WO2023032679A1 - High frequency circuit, and communication device - Google Patents

Abstract

A high-frequency circuit (1) equipped with a power amplification circuit (10) which corresponds to a first power class which allows a first maximum output power that is equal to or greater than the maximum output power allowed by a power class 2, a filter circuit (60) which is connected to the output end of the power amplification circuit (10) and has a passband that includes the uplink operation band of a band A for frequency division duplexing, a directional coupler (31), and a control circuit (70) for controlling the power amplification circuit (10), wherein: the directional coupler (31) has an input port (311) connected to the output end of the power amplification circuit (10), an output port (312) connected to an antenna connection terminal (101), and a coupling port (313) connected to the control circuit (70) and the external connection terminal (141); and the control circuit (70) restricts amplification of the high-frequency signal via the power amplification circuit (10) on the basis of a first signal from the coupling port (313).

Description

High frequency circuit and communication device

The present invention relates to high frequency circuits and communication devices.

In 3GPP (registered trademark) (3rd Generation Partnership Project), frequency division duplex (FDD) bands for power classes that allow higher maximum output power than before (e.g. power classes 1, 1.5, 2, etc.) Its application to

U.S. Patent Application Publication No. 2015/0133067

However, if a power class that allows a higher maximum output power than before is applied to the FDD band, the module may be damaged by high power signals.

Therefore, the present invention provides a high-frequency circuit and a communication device that can suppress module damage due to high-power signals.

A high-frequency circuit according to an aspect of the present invention includes: a power amplifier circuit corresponding to a first power class that allows a first maximum output power that is equal to or higher than the maximum output power allowed in power class 2; a first filter circuit having a passband including an uplink operating band of a first band for frequency division duplexing; a directional coupler; and a control circuit for controlling the power amplifier circuit; has an input port connected to the output terminal of the power amplifier circuit via the first filter circuit, an output port connected to the antenna connection terminal, and a coupling port connected to the control circuit and the external connection terminal. The control circuit limits amplification of the high frequency signal by the power amplifier circuit based on the first signal from the coupling port.

A high-frequency circuit according to an aspect of the present invention includes: a power amplifier circuit corresponding to a first power class that allows a first maximum output power that is equal to or higher than the maximum output power allowed in power class 2; a first filter circuit having a passband including a first band uplink operating band for frequency division duplexing, a first directional coupler and a second directional coupler, and a control circuit for controlling a power amplifier circuit. and, the first directional coupler has a first input port connected to the output terminal of the power amplifier circuit via the first filter circuit, a first output port connected to the antenna connection terminal, and an external a first coupling port connected to the connection terminal; the second directional coupler has a second input port connected to the output end of the power amplifier circuit; and the antenna connection terminal via the first filter circuit. and a second coupling port coupled to a control circuit, wherein the control circuit amplifies a high frequency signal by a power amplifier circuit based on a first signal from the second coupling port. limit.

According to the high-frequency circuit according to one aspect of the present invention, it is possible to suppress the module from being damaged by a high-power signal.

FIG. 1 is a circuit configuration diagram of a high-frequency circuit and a communication device according to Embodiment 1. FIG. FIG. 2 is a functional configuration diagram of the control circuit according to the first embodiment. FIG. 3 is a flow chart showing processing of the control circuit according to the first embodiment. FIG. 4 is a circuit configuration diagram of a high-frequency circuit and a communication device according to Embodiment 2. FIG. FIG. 5 is a circuit configuration diagram of a high-frequency circuit and a communication device according to the third embodiment. FIG. 6 is a circuit configuration diagram of a high-frequency circuit and a communication device according to the fourth embodiment. FIG. 7 is a circuit configuration diagram of a high-frequency circuit and a communication device according to the fifth embodiment. FIG. 8 is a circuit configuration diagram of a high frequency circuit and a communication device according to another embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the embodiments described below are all comprehensive or specific examples. Numerical values, shapes, materials, components, arrangement of components, connection forms, and the like shown in the following embodiments are examples, and are not intended to limit the present invention.

In addition, each drawing is a schematic diagram that has been appropriately emphasized, omitted, or adjusted in proportion to show the present invention, and is not necessarily strictly illustrated, and the actual shape, positional relationship, and ratio may differ. In each figure, substantially the same configurations are denoted by the same reference numerals, and redundant description may be omitted or simplified.

In the circuit configuration of the present invention, "connected" includes not only direct connection with connection terminals and/or wiring conductors, but also electrical connection via other circuit elements. "Directly connected" means directly connected by connection terminals and/or wiring conductors without intervening other circuit elements. "Connected between A and B" means connected to both A and B between A and B, in addition to being connected in series with the path connecting A and B , is connected between the path and ground.

(Embodiment 1)
[1.1 Circuit configuration of high-frequency circuit 1 and communication device 5]
A circuit configuration of a high-frequency circuit 1 according to Embodiment 1 and a communication device 5 including the same will be described with reference to FIG. FIG. 1 is a circuit configuration diagram of a high-frequency circuit 1 and a communication device 5 according to this embodiment.

[1.1.1 Circuit Configuration of Communication Device 5]
First, the communication device 5 will be described. The communication device 5 corresponds to a so-called UE, and is typically a mobile phone, smart phone, tablet computer, or the like. Such a communication device 5 includes a high frequency circuit 1 , an antenna 2 , an RFIC (Radio Frequency Integrated Circuit) 3 and a BBIC (Baseband Integrated Circuit) 4 .

The high frequency circuit 1 transmits high frequency signals between the antenna 2 and the RFIC 3 . The internal configuration of the high frequency circuit 1 will be described later.

The antenna 2 is connected to the antenna connection terminal 101 of the high frequency circuit 1 . The antenna 2 receives a high frequency signal from the high frequency circuit 1 and outputs it to the outside.

The RFIC 3 is an example of a signal processing circuit that processes high frequency signals. Specifically, the RFIC 3 performs signal processing such as up-conversion on the transmission signal input from the BBIC 4 , and outputs the high-frequency transmission signal generated by the signal processing to the transmission path of the high-frequency circuit 1 . The RFIC 3 also has a control section that controls the switch circuit, amplifier circuit, and the like of the high-frequency circuit 1 . A part or all of the functions of the RFIC 3 as a control unit may be configured outside the RFIC 3 , for example, in the BBIC 4 or the high frequency circuit 1 .

The BBIC 4 is a baseband signal processing circuit that performs signal processing using an intermediate frequency band that is lower in frequency than the high frequency signal transmitted by the high frequency circuit 1 . Signals processed by the BBIC 4 include, for example, image signals for image display and/or audio signals for calling through a speaker.

Note that the antenna 2 and the BBIC 4 are not essential components in the communication device 5 according to the present embodiment.

[1.1.2 Circuit configuration of high-frequency circuit 1]
Next, the high frequency circuit 1 will be described. As shown in FIG. 1, the high frequency circuit 1 includes a power amplifier circuit 10, a directional coupler 31, a filter circuit 60, a control circuit 70, an antenna connection terminal 101, a high frequency input terminal 111, a control terminal 131 , and external output terminals 141 and 142 .

The antenna connection terminal 101 is connected to the antenna 2 outside the high frequency circuit 1 .

A high-frequency input terminal 111 is an input terminal for receiving a transmission signal of band A for FDD from the outside of the high-frequency circuit 1 . In this embodiment, the high frequency input terminal 111 is connected to the RFIC 3 outside the high frequency circuit 1 .

Band A is an example of the first band, and is constructed using a radio access technology (RAT: Radio Access Technology) predefined by standardization organizations (for example, 3GPP and IEEE (Institute of Electrical and Electronics Engineers), etc.) It is a frequency band for a communication system that uses Examples of communication systems that can be used include, but are not limited to, 5GNR (5th Generation New Radio) systems, LTE (Long Term Evolution) systems, and WLAN (Wireless Local Area Network) systems.

The control terminal 131 is connected to the RFIC 3 outside the high frequency circuit 1 . The control terminal 131 is a terminal for transmitting control signals. That is, the control terminal 131 is a terminal for receiving a control signal from the outside of the high frequency circuit 1 and/or a terminal for supplying a control signal to the outside of the high frequency circuit 1 . A control signal is a signal relating to control of an electronic circuit included in the high-frequency circuit 1 . Specifically, the control signal is a digital signal for controlling the power amplifier circuit 10 .

Each of the external output terminals 141 and 142 is a terminal for supplying a signal to the outside of the high frequency circuit 1 . Outside the high frequency circuit 1 , each of the external output terminals 141 and 142 is connected to the RFIC 3 . Inside the high-frequency circuit 1 , the external output terminal 141 is connected to the coupling port 313 of the directional coupler 31 , and the external output terminal 142 is connected to the isolation port 314 of the directional coupler 31 .

The power amplifier circuit 10 is connected between the high frequency input terminal 111 and the filter circuit 60, and can amplify the transmission signal of band A using the power supply voltage supplied from the outside of the high frequency circuit 1. The power amplifier circuit 10 corresponds to a first power class that allows a first maximum output power that is equal to or higher than the maximum output power allowed in power class 2 .

A power class is a classification of UE output power defined by maximum output power, etc. A smaller power class value indicates that a higher power output is allowed. For example, in 3GPP, the maximum allowed output power for power class 1 is 31 dBm, the maximum allowed output power for power class 1.5 is 29 dBm, the maximum allowed output power for power class 2 is 26 dBm, and the maximum allowed output power for power class 2 is 26 dBm. 3 is 23 dBm.

The first power class is a power class that allows a maximum output power of 26 dBm or more that is allowed in power class 2. Therefore, in 5GNR FR1 (Frequency Range 1), the first power class is power class 1 that allows a maximum output power of 31 dBm, power class 1.5 that allows a maximum output power of 29 dBm, and a maximum output power of 26 dBm. Any of the power classes 2 and 2 can be used.

　The maximum output power of the UE is defined as the output power at the antenna end of the UE. The measurement of the maximum output power of the UE is done, for example, in a manner defined by 3GPP or the like. For example, in FIG. 1 the maximum output power is measured by measuring the radiated power at antenna 2 . Instead of measuring the radiation power, it is also possible to measure the output power of the antenna 2 by providing a terminal near the antenna 2 and connecting a measuring instrument (such as a spectrum analyzer) to the terminal.

Also, the power class to which the power amplifier circuit corresponds can be specified by the maximum output power of the power amplifier circuit. For example, the maximum output power of a power amplifier circuit corresponding to power class 2 is greater than 26 dBm. Generally, the higher the maximum output power, the larger the size of the power amplifier circuit. Therefore, by comparing the sizes of the two power amplifier circuits, it may be possible to make a relative comparison of the power classes supported by the two power amplifier circuits.

In this embodiment, the power amplifier circuit 10 includes a power amplifier 11 . The power amplifier 11 corresponds to the first power class. That is, the power amplifier 11 can amplify the transmission signal of band A to power higher than the first maximum output power allowed in the first power class. Note that the configuration of the power amplifier circuit 10 is not limited to this. For example, the power amplifier circuit 10 may be a multistage amplifier circuit.

The directional coupler 31 can extract part of the power propagating in a specific direction on the path between the filter circuit 60 and the antenna connection terminal 101 . Here, the directional coupler 31 is a bidirectional coupler, and extracts part of the forward propagating power (progressive wave) and part of the backward propagating power (reflected wave). can be done.

The directional coupler 31 has an input port 311 , an output port 312 , a coupled port 313 and an isolated port 314 . The input port 311 is a port to which power (traveling wave) is applied, and is connected to the output end of the power amplifier circuit 10 via the filter circuit 60 . The coupling port 313 is a port to which part of the power (traveling wave) applied to the input port 311 is coupled, and is connected to the control circuit 70 and the external output terminal 141 . The output port 312 is a port that outputs the other part of the power (traveling wave) applied to the input port 311 and is connected to the antenna connection terminal 101 . The isolation port 314 is a port to which part of the power (reflected wave) applied to the output port 312 is coupled, and is connected to the control circuit 70 and the external output terminal 142 .

The filter circuit 60 is an example of a first filter circuit and has a passband that includes the Band A uplink operating band. Filter circuit 60 is connected between antenna connection terminal 101 and power amplifier circuit 10 . In this embodiment, the filter circuit 60 comprises a filter 61 having a passband that includes the Band A uplink operating band.

The filter 61 is connected between the antenna connection terminal 101 and the power amplifier circuit 10 . Specifically, one end of the filter 61 is connected to the output end of the power amplifier 11 , and the other end of the filter 61 is connected to the antenna connection terminal 101 via the directional coupler 31 . Filter 61 corresponds to the first power class. That is, the filter 61 has power durability corresponding to the first power class. As a result, the filter circuit 60 can pass the band A transmission signal amplified by the power amplifier circuit 10 to an output power higher than the first maximum output power.

The filter 61 may be configured using, for example, a surface acoustic wave (SAW) filter, a bulk acoustic wave (BAW) filter, an LC resonance filter, or a dielectric filter, and further are not limited to these.

The control circuit 70 is connected to the control terminal 131 and can control the power amplifier circuit 10 and the like. Specifically, the control circuit 70 receives a digital control signal from the RFIC 3 via the control terminal 131 and outputs the control signal to the power amplifier circuit 10 and the like.

Also, the control circuit 70 is connected to the coupling port 313 and the isolation port 314 of the directional coupler 31 . Specifically, the control circuit 70 is connected to the coupling port 313 via a branch path branched from the path connecting the coupling port 313 and the external output terminal 141, and is connected to the isolation port 314 and the external output terminal 142. is connected to the isolation port 314 via a branch path branched from. Note that the control circuit 70 may be directly connected to the directional coupler 31 without passing through the branch path. The control circuit 70 limits the amplification of the high frequency signal by the power amplifier circuit 10 based on the signal (first signal) from the coupling port 313 and the signal (second signal) from the isolation port 314 .

Note that the circuit configuration of the high-frequency circuit 1 in FIG. 1 is an example, and is not limited to this. For example, the high-frequency circuit 1 includes a switch connected between the antenna connection terminal 101 and the directional coupler 31 and/or a switch connected between the directional coupler 31 and the filter circuit 60. good too.

[1.2 Functional Configuration of Control Circuit 70]
Next, the functional configuration of the control circuit 70 will be described with reference to FIG. FIG. 2 is a functional configuration diagram of the control circuit 70 according to the first embodiment.

The control circuit 70 includes preamplifiers 701 a and 701 b, detectors 702 a and 702 b, a power calculator 703 , a comparator 704 and a controller 705 .

Preamplifiers 701a and 701b amplify the signal from the coupling port 313 and the signal from the isolation port 314, respectively. Thereby, the preamplifier 701a can amplify the signal corresponding to the traveling wave, and the preamplifier 701b can amplify the signal corresponding to the reflected wave.

Detectors 702a and 702b detect modulated signals from the signals amplified by preamplifiers 701a and 701b, respectively. As a result, the power value P3 of the signal from the coupling port 313 and the power value P4 of the signal from the isolation port 314 can be obtained.

A power calculator 703 calculates the power supply value Ps supplied to the directional coupler 31 . Specifically, power calculator 703 calculates the sum (P3+P4) of power value P3 of the signal from coupling port 313 and power value P4 from isolation port 314 as supply power value Ps. The power calculator 703 may calculate the weighted sum of the power values P3 and P4 as the supplied power value Ps. At this time, the weight of each of the power values P3 and P4 may be determined in advance empirically and/or experimentally. Note that 0 can also be used as the weight of the power value P3 or P4.

The comparator 704 compares the power supply value Ps calculated by the power calculator 703 with the threshold value Pth, and outputs the comparison result to the controller 705 . As the threshold value Pth, the maximum power value allowed in the high-frequency circuit 1 can be used, and an empirically and/or experimentally predetermined value may be used.

Note that the comparator 704 does not necessarily have to compare the power supply value Ps with the threshold value Pth. For example, the comparator 704 may compare only one of the power value P3 of the signal from the coupling port 313 and the power value P4 of the signal from the isolation port 314 with the threshold value Pth. In this case, the power calculator 703 does not need to calculate the supplied power value Ps.

The controller 705 limits amplification of the high frequency signal by the power amplifier circuit 10 based on the comparison result. Specifically, when the power supply value Ps is greater than or equal to the threshold value Pth, the controller 705 limits amplification of the high-frequency signal by the power amplifier circuit 10 . On the other hand, when the power supply value Ps is less than the threshold value Pth, the controller 705 does not limit amplification of the high frequency signal by the power amplifier circuit 10 .

A bias current supplied to the power amplifier circuit 10 can be used to limit the amplification of the high-frequency signal by the power amplifier circuit 10 . In this case, the controller 705 reduces the bias current based on the control signal from the RFIC 3 when the power supply value Ps is greater than or equal to the threshold value Pth. For reducing the bias current, for example, an attenuator for reducing the bias current can be used. A method for reducing the bias current is not particularly limited.

Also, the power supply voltage supplied to the power amplifier circuit 10 may be used to limit the amplification of the high-frequency signal by the power amplifier circuit 10 . For example, the controller 705 may stop supplying the power supply voltage when the power supply value Ps is greater than or equal to the threshold value Pth.

[1.3 Processing of Control Circuit 70]
Next, processing by the control circuit 70 configured as described above will be described with reference to FIG. FIG. 3 is a flow chart showing processing of the control circuit 70 according to the first embodiment.

First, the preamplifier 701a and the detector 702a acquire the power value P3 of the signal from the coupling port 313 (S101). Furthermore, the preamplifier 701b and the detector 702b acquire the power value P4 of the signal from the coupling port 313 (S102).

Next, the power calculator 703 calculates the power supply value Ps (S103). For example, power calculator 703 calculates the sum of power values P3 and P4 as supply power value Ps.

Then, the comparator 704 compares the calculated power supply value Ps with the threshold value Pth (S104). Specifically, comparator 704 determines whether power supply value Ps is greater than or equal to threshold value Pth.

Here, if the power supply value Ps is greater than or equal to the threshold value Pth (Yes in S104), the controller 705 limits the amplification of the high frequency signal in the power amplifier circuit 10 (S105), and ends the process.

On the other hand, if the power supply value Ps is less than the threshold value Pth (No in S104), the controller 705 ends the process without limiting the amplification of the high-frequency signal in the power amplifier circuit 10. That is, step S105 is skipped.

The order of processing in the flowchart of FIG. 3 is an example, and is not limited to this. For example, steps S101 and S102 may be performed at the same time or their order may be changed.

[1.4 Effect etc.]
As described above, the high-frequency circuit 1 according to the present embodiment includes the power amplifier circuit 10 corresponding to the first power class that allows the first maximum output power that is equal to or higher than the maximum output power allowed in the power class 2, and the power amplifier circuit 10 a filter circuit 60 connected to the output of the circuit 10 and having a passband including the band A uplink operating band for frequency division duplexing; a directional coupler 31; and a control circuit 70 for controlling the power amplifier circuit 10; , the directional coupler 31 includes an input port 311 connected to the output end of the power amplifier circuit 10 via the filter circuit 60, an output port 312 connected to the antenna connection terminal 101, a control circuit 70 and and a coupling port 313 connected to the external connection terminal 141 , and the control circuit 70 limits amplification of the high-frequency signal by the power amplifier circuit 10 based on the first signal from the coupling port 313 .

According to this, the amplification of the power amplifier circuit 10 is limited based on the signal corresponding to the traveling wave, and the limitation is performed by the control circuit 70. Since the control circuit 70 is included in the high frequency circuit 1, quicker feedback control is possible. For example, when a high-frequency signal with an output power exceeding the maximum output power allowed by the high-frequency circuit 1 is output, the amplification of the power amplifier circuit 10 can be quickly limited, and the module will not be damaged by the high-power signal. can be suppressed. In particular, in the FDD band, there is no switching between transmission and reception, and high-frequency signals are continuously transmitted. Furthermore, the directional coupler 31 connected to the external connection terminal 141 for feedback control by the RFIC 3 or the like can be used for feedback control by the control circuit 70 . Therefore, an increase in the number of directional couplers included in the high frequency circuit 1 can be suppressed.

Further, for example, in the high-frequency circuit 1 according to the present embodiment, the control circuit 70 may limit the amplification of the high-frequency signal by the power amplifier circuit 10 by stopping the supply of the power supply voltage to the power amplifier circuit 10. .

According to this, since the amplification of the power amplifier circuit 10 is restricted using the power supply voltage, faster feedback control can be realized.

Further, for example, in the high-frequency circuit 1 according to the present embodiment, the control circuit 70 may limit the amplification of the high-frequency signal by the power amplifier circuit 10 by reducing the bias current of the power amplifier circuit 10 .

According to this, since the amplification of the power amplifier circuit 10 is limited using the bias current, feedback control can be realized more easily.

Further, for example, in the high-frequency circuit 1 according to the present embodiment, the control circuit 70 limits the amplification of the high-frequency signal by the power amplifier circuit 10 when the power value of the first signal from the coupling port 313 is equal to or greater than the threshold. Alternatively, if the power value of the first signal from the coupling port 313 is less than the threshold, the amplification of the high frequency signal by the power amplifier circuit 10 may not be restricted.

According to this, when the power value of the traveling wave is large, the amplification of the power amplifier circuit 10 can be limited, and when a high frequency signal with an output power exceeding the maximum output power allowed by the high frequency circuit 1 is output, , the amplification of the power amplifier circuit 10 can be limited quickly.

Further, for example, in the high-frequency circuit 1 according to the present embodiment, the directional coupler 31 may further include an isolation port 314 connected to the control circuit 70 , and the control circuit 70 connects the coupling port 313 to Amplification of the high frequency signal by the power amplifier circuit 10 may be limited based on the first signal from the isolation port 314 and the second signal from the isolation port 314 .

According to this, the amplification of the power amplifier circuit 10 is limited based on not only the traveling wave but also the reflected wave, so feedback control based on the power supplied to the directional coupler 31 is possible. Therefore, it is possible to more accurately reflect the power of the high-frequency signal passing through the components on the transmission path (for example, the filter circuit 60, etc.) in the control, and to more effectively suppress damage to the module due to high-power signals. .

Further, for example, in the high-frequency circuit 1 according to the present embodiment, the control circuit 70 determines that the sum of the power value of the first signal from the coupling port 313 and the power value of the second signal from the isolation port 314 is equal to or greater than the threshold. In this case, the amplification of the high frequency signal by the power amplifier circuit 10 may be restricted, and when the sum of the power value of the first signal and the power value of the second signal is less than the threshold, the power amplifier circuit 10 may limit the amplification of the high frequency signal. Amplification need not be limited.

According to this, when the sum of the power value of the forward wave and the power value of the reflected wave is large, the amplification of the power amplifier circuit 10 can be limited, and the components (for example, the filter circuit 60) on the transmission path allow When a high-frequency signal with power exceeding the maximum output power is output, the amplification of the power amplifier circuit 10 can be quickly limited.

Further, the communication device 5 according to the present embodiment includes an RFIC 3 that processes high frequency signals, and a high frequency circuit 1 that transmits high frequency signals between the RFIC 3 and the antenna 2 .

According to this, the effect of the high-frequency circuit 1 can be realized in the communication device 5.

(Embodiment 2)
Next, Embodiment 2 will be described. The present embodiment is mainly different from the first embodiment in that connection and disconnection between the directional coupler 31 and the control circuit 70 can be switched. The present embodiment will be described below with reference to FIG. 4, focusing on the differences from the first embodiment.

[2.1 Circuit Configuration of High Frequency Circuit 1A]
FIG. 4 is a circuit configuration diagram of a high frequency circuit 1A and a communication device 5A according to this embodiment. Note that the communication device 5A is the same as the communication device 5 according to the first embodiment except that the high frequency circuit 1A is provided instead of the high frequency circuit 1, so the description is omitted.

The high frequency circuit 1A includes a power amplifier circuit 10, a directional coupler 31, switches 32 and 33, a filter circuit 60, a control circuit 70, an antenna connection terminal 101, a high frequency input terminal 111, and a control terminal 131. , and external output terminals 141 and 142 .

The switch 32 is an example of a first switch and is connected between the coupling port 313 of the directional coupler 31 and the control circuit 70 . Switch 32 has terminals 321 and 322 . Terminal 321 is connected to coupling port 313 . Terminal 322 is connected to control circuit 70 .

In this connection configuration, the switch 32 can switch connection and disconnection of the terminals 321 and 322 based on a control signal from the RFIC 3, for example. That is, the switch 32 can switch connection and disconnection of the coupling port 313 and the control circuit 70 . Here, the switch 32 connects the coupling port 313 to the control circuit 70 when the first power class is applied to the transmission of band A signals, and connects the coupling port 313 to the control circuit 70 when the second power class is applied to the transmission of the band A signals. Also, coupling port 313 is not connected to control circuit 70 . The switch 32 is configured by, for example, an SPST (Single-Pole Single-Throw) type switch circuit.

The second power class is a power class that allows a second maximum output power that is lower than the first maximum output power that is allowed in the first power class. For example, if power class 2, which allows a maximum output power of 26 dBm, is used as the first power class, power class 3, which allows a maximum output power of 23 dBm, can be used as the second power class.

The switch 33 is an example of a second switch and is connected between the isolation port 314 of the directional coupler 31 and the control circuit 70. The switch 33 has terminals 331 and 332 . Terminal 331 is connected to isolation port 314 . Terminal 332 is connected to control circuit 70 .

In this connection configuration, the switch 33 can switch connection and disconnection of the terminals 331 and 332 based on a control signal from the RFIC 3, for example. That is, the switch 33 can switch connection and disconnection of the isolation port 314 and the control circuit 70 . Here, the switch 33 connects the isolation port 314 to the control circuit 70 when the first power class is applied to transmission of band A signals, and the second power class is applied to transmission of band A signals. , the isolation port 314 is not connected to the control circuit 70 . The switch 33 is configured by, for example, an SPST type switch circuit.

[2.2 Effects, etc.]
As described above, the high-frequency circuit 1A according to the present embodiment may further include the switch 32 connected between the coupling port 313 and the control circuit 70. The switch 32 is used for transmitting band A signals. The coupling port 313 may be connected to the control circuit 70 when a first power class is applied to the second power class allowing a second maximum output power lower than the first maximum output power for the transmission of signals in band A. The coupling port 313 may not be connected to the control circuit 70 when the power class is applied.

According to this, when the second power class is applied to transmission of band A signals, the control circuit 70 is not connected to the coupling port 313 . Therefore, the extraction of a portion of the signal from the coupling port 313 to the control circuit 70 can be discontinued when the module is unlikely to be damaged by a high power signal. When the second power class is applied, the power of the signal from the coupling port 313 is also reduced. Therefore, by interrupting the extraction of the signal to the control circuit 70, the signal is output to the RFIC 3 or the like via the external output terminal 141. It is possible to suppress the decrease in the signal level caused by the

Further, for example, the high-frequency circuit 1A according to the present embodiment may further include a switch 33 connected between the isolation port 314 and the control circuit 70. The switch 33 is used for transmitting band A signals. Isolation port 314 may be connected to control circuit 70 when a first power class is applied and a second power class permitting a second maximum output power lower than the first maximum output power for transmission of band A signals. The isolation port 314 may not be connected to the control circuit 70 when the power class is applied.

According to this, the control circuit 70 is not connected to the isolation port 314 when the second power class is applied to transmission of band A signals. Therefore, when the possibility of module damage due to high power signals is low, extraction of a portion of the signal from the isolation port 314 to the control circuit 70 can be discontinued. When the second power class is applied, the power of the signal from the isolation port 314 is also reduced. Therefore, by interrupting the extraction of the signal to the control circuit 70, the signal is output to the RFIC 3 or the like via the external output terminal 142. It is possible to suppress a decrease in the signal level that is received.

(Embodiment 3)
Next, Embodiment 3 will be described. This embodiment mainly differs from the above-described first embodiment in that in addition to band A for FDD, band B for time division duplex (TDD) is also supported. The present embodiment will be described below with reference to FIG. 5, focusing on the differences from the first embodiment.

[3.1 Circuit Configuration of High Frequency Circuit 1B]
FIG. 5 is a circuit configuration diagram of a high frequency circuit 1B and a communication device 5B according to this embodiment. Note that the communication device 5B is the same as the communication device 5 according to the first embodiment except that the high-frequency circuit 1B is provided instead of the high-frequency circuit 1, so the description is omitted.

The high frequency circuit 1B includes a power amplifier circuit 10B, a directional coupler 31, switches 51 to 54, filter circuits 601 and 602, a control circuit 70, an antenna connection terminal 101, a high frequency input terminal 111, and a high frequency output. A terminal 121 , a control terminal 131 , and external output terminals 141 and 142 are provided.

A high-frequency input terminal 111 is an input terminal for receiving a transmission signal of band A for FDD and a transmission signal of band B for TDD from the outside of the high-frequency circuit 1B. In this embodiment, the high frequency input terminal 111 is connected to the RFIC 3 outside the high frequency circuit 1B.

The high-frequency output terminal 121 is an output terminal for supplying a received signal of band A for FDD and a received signal of band B for TDD to the outside of the high-frequency circuit 1B. In this embodiment, the high frequency output terminal 121 is connected to the RFIC 3 outside the high frequency circuit 1B.

The power amplifier circuit 10B is connected between the high frequency input terminal 111 and the filter circuits 601 and 602, and can amplify the transmission signals of the bands A and B using the power supply voltage supplied from the outside of the high frequency circuit 1B. . The power amplifier circuit 10B corresponds to a first power class that allows a first maximum output power that is equal to or higher than the maximum output power allowed in power class 2 .

In this embodiment, the power amplifier circuit 10B includes a power amplifier 11B. The power amplifier 11B corresponds to the first power class. That is, the power amplifier 11B can amplify the transmission signals of the bands A and B to power higher than the first maximum output power allowed in the first power class.

The low noise amplifier 21 is connected between the filter circuits 601 and 602 and the high frequency output terminal 121, and can amplify the received signals of the bands A and B using the power supply voltage supplied from the outside of the high frequency circuit 1B. .

The filter circuit 601 is an example of a first filter circuit, and can pass transmission signals and reception signals of band A for FDD. The filter circuit 601 has filters 61 and 62 .

The filter 61 has a passband including the uplink operating band of band A, and is connected between the antenna connection terminal 101 and the power amplifier circuit 10B. Specifically, one end of the filter 61 is connected via the switch 52 to the output terminal of the power amplifier 11B, and the other end of the filter 61 is connected via the switch 51 to the antenna connection terminal 101 . Filter 61 corresponds to the first power class. That is, the filter 61 has power durability corresponding to the first power class. As a result, the filter circuit 601 can pass the band A transmission signal that has been amplified to an output power higher than the first maximum output power by the power amplifier circuit 10B.

The filter 62 has a passband that includes the downlink operation band of band A and is connected between the antenna connection terminal 101 and the low noise amplifier 21 . Specifically, one end of filter 62 is connected to antenna connection terminal 101 via switch 51 , and the other end of filter 62 is connected to the input terminal of low noise amplifier 21 via switch 54 .

The filter circuit 602 is an example of a second filter circuit, and can pass the transmission signal and reception signal of band B for TDD. The filter circuit 602 has a filter 63 .

The filter 63 has a passband including band B, and is connected between the antenna connection terminal 101 and the power amplifier circuit 10B and the low noise amplifier 21. Specifically, one end of the filter 63 is connected to the antenna connection terminal 101 via the switch 51, the other end of the filter 63 is connected to the output terminal of the power amplifier 11B via the switches 53 and 52, and the switch 53 and 54 to the input end of the low noise amplifier 21 . Filter 63 corresponds to the first power class. That is, the filter 63 has power durability corresponding to the first power class. As a result, the filter circuit 602 can pass the transmission signal of band B that has been amplified to an output power higher than the first maximum output power by the power amplifier circuit 10B.

Band B is an example of a second band, and is a frequency band for a communication system built using a RAT predefined by a standardization organization or the like.

The switch 51 is connected between the antenna connection terminal 101 and the filter circuits 601 and 602 . The switch 51 has terminals 511-513. Terminal 511 is connected to antenna connection terminal 101 via directional coupler 31 . Terminal 512 is connected to filter circuit 601 . Terminal 513 is connected to filter circuit 602 .

In this connection configuration, the switch 51 can connect the terminal 511 to either of the terminals 512 and 513 based on a control signal from the RFIC 3, for example. That is, the switch 51 can switch the connection of the antenna connection terminal 101 between the filter circuits 601 and 602 . The switch 51 is configured by, for example, an SPDT (Single-Pole Double-Throw) type switch circuit.

The switch 52 is connected between the power amplifier circuit 10B and the filters 61 and 63. The switch 52 has terminals 521-523. Terminal 521 is connected to power amplifier circuit 10B. Terminal 522 is connected to filter 61 . Terminal 523 is connected to filter 63 via switch 53 .

In this connection configuration, the switch 52 can connect the terminal 521 to either of the terminals 522 and 523 based on a control signal from the RFIC 3, for example. That is, the switch 52 can switch the connection of the power amplifier circuit 10B between the filters 61 and 63. FIG. The switch 52 is composed of, for example, an SPDT type switch circuit.

The switch 53 is connected between the filter 63 and the power amplifier circuit 10B and the low noise amplifier 21. The switch 53 has terminals 531-533. Terminal 531 is connected to filter 63 . Terminal 532 is connected via switch 52 to the output terminal of power amplifier 11B. Specifically, terminal 532 is connected to terminal 523 of switch 52 . Terminal 533 is connected to the input terminal of low noise amplifier 21 via switch 54 . Specifically, terminal 533 is connected to terminal 543 of switch 54 .

In this connection configuration, the switch 53 can connect the terminal 531 to either of the terminals 532 and 533 based on a control signal from the RFIC 3, for example. That is, the switch 53 can switch the connection of the filter 63 between the power amplifier 11B and the low noise amplifier 21. FIG. The switch 53 is composed of, for example, an SPDT type switch circuit.

A switch 54 is connected between the low noise amplifier 21 and the filters 62 and 63 . The switch 54 has terminals 541-543. Terminal 541 is connected to the input terminal of low noise amplifier 21 . Terminal 542 is connected to filter 62 . Terminal 543 is connected to filter 63 via switch 53 .

In this connection configuration, the switch 54 can connect the terminal 541 to either of the terminals 542 and 543 based on a control signal from the RFIC 3, for example. That is, the switch 54 can switch the connection of the low noise amplifier 21 between the filters 62 and 63 . The switch 54 is composed of, for example, an SPDT type switch circuit.

Note that the circuit configurations of the high-frequency circuit 1B and the communication device 5B in FIG. 5 are merely examples, and are not limited thereto. For example, although the low noise amplifier 21 is shared by the bands A and B in FIG. In this case, one of the two low noise amplifiers should be connected to the filter 62 and the other of the two low noise amplifiers should be connected to the filter 63 . Also, in FIG. 5, the antenna 2 is shared by the bands A and B, but the communication device 5B may have two antennas for the bands A and B separately.

[3.2 Effects, etc.]
As described above, the high frequency circuit 1B according to the present embodiment further includes the filter circuit 602 connected to the output terminal of the power amplifier circuit 10B and having a passband including the band B for time division duplexing.

According to this, not only the band A for FDD but also the band B for TDD can achieve the same effect as the high-frequency circuit 1 according to the first embodiment.

(Embodiment 4)
Next, Embodiment 4 will be described. The present embodiment differs from the first embodiment mainly in that two power amplifiers connected in parallel are used in the power amplifier circuit. The present embodiment will be described below with reference to FIG. 6, focusing on the differences from the first embodiment.

[4.1 Circuit Configuration of High Frequency Circuit 1C]
FIG. 6 is a circuit configuration diagram of a high frequency circuit 1C and a communication device 5C according to this embodiment. Note that the communication device 5C is the same as the communication device 5 according to the first embodiment except that the high frequency circuit 1C is provided instead of the high frequency circuit 1, so the description is omitted.

The high frequency circuit 1C includes a power amplifier circuit 10C, a directional coupler 31, transformers 41 and 42, a filter circuit 60C, a control circuit 70, an antenna connection terminal 101, a high frequency input terminal 111, and a control terminal 131. , and external output terminals 141 and 142 .

The power amplifier circuit 10C is connected between the high frequency input terminal 111 and the filter circuit 60C, and can amplify the transmission signal of band A using the power supply voltage supplied from the outside of the high frequency circuit 1C. The power amplifier circuit 10C corresponds to a first power class that allows a first maximum output power that is equal to or higher than the maximum output power allowed in power class 2 . In this modification, the power amplifier circuit 10C includes power amplifiers 11a and 11b connected in parallel.

The power amplifier 11 a is an example of a first power amplifier, and can amplify one of the two signals distributed by the transformer 41 . Here, the power amplifier 11a alone does not have to support the first power class. That is, the power amplifier 11a may not be able to amplify the transmission signal of band A to power higher than the first maximum output power allowed in the first power class.

The power amplifier 11b is an example of a second power amplifier, and can amplify the other of the two signals distributed by the transformer 41. Here, the power amplifier 11b alone does not have to support the first power class. That is, the power amplifier 11b may not be able to amplify the transmission signal of band A to power higher than the first maximum output power allowed in the first power class.

Thus, in this embodiment, the power amplifiers 11a and 11b do not have to individually correspond to the first power class. By synthesizing the two signals amplified by the two power amplifiers 11a and 11b, the band A transmission signal can be amplified to a power higher than the first maximum output power allowed in the first power class.

Note that the power amplifier circuit 10C may be a multistage amplifier circuit. At this time, the power amplifier circuit 10C may include two power amplifiers connected to the input terminals of the power amplifiers 11a and 11b, respectively, as power amplifiers corresponding to the input stage. Moreover, the power amplifier circuit 10C may include one power amplifier connected to the input terminals of the power amplifiers 11a and 11b as a power amplifier corresponding to the input stage. In this case, one power amplifier may be connected between the input terminal 411 of the transformer 41 and the high frequency input terminal 111 .

The transformer 41 functions as a distributor and can distribute one signal into two signals with phases opposite to each other. Transformer 41 includes input terminal 411 , ground terminal 412 , output terminals 413 and 414 , primary coil 415 and secondary coil 416 .

The input terminal 411 constitutes one end of the primary coil 415 . The input terminal 411 is connected to the high frequency input terminal 111 .

The ground terminal 412 constitutes the other end of the primary coil 415 . A ground terminal 412 is connected to the ground.

The output terminal 413 constitutes one end of the secondary coil 416 . The output terminal 413 is connected to the input terminal of the power amplifier 11a.

The output terminal 414 constitutes the other end of the secondary coil 416 . The output terminal 414 is connected to the input terminal of the power amplifier 11b.

The transformer 42 is an example of a synthesizer, and can synthesize two signals with opposite phases to each other. Transformer 42 includes input terminals 421 and 422 , output terminal 423 , ground terminal 424 , primary coil 425 and secondary coil 426 .

The input terminal 421 is an example of a first input terminal and constitutes one end of the primary coil 425 . The input terminal 421 is connected to the output terminal of the power amplifier 11a through the filter 61a.

The input terminal 422 is an example of a second input terminal and constitutes the other end of the primary coil 425 . The input terminal 422 is connected to the output terminal of the power amplifier 11b through the filter 61b.

The output terminal 423 constitutes one end of the secondary coil 426 . The output terminal 423 is connected to the antenna connection terminal 101 .

The ground terminal 424 constitutes the other end of the secondary coil 426 . Ground terminal 424 is connected to the ground.

Although the transformer 42 is used as the combiner in this embodiment, the combiner is not limited to this. For example, a Wilkinson synthesizer may be used as the synthesizer.

The filter circuit 60C is an example of a first filter circuit and has a passband that includes the band A uplink operating band. Filter circuit 60C is connected between antenna connection terminal 101 and power amplifier circuit 10C. In this variant, the filter circuit 60C comprises filters 61a and 61b each having a passband that includes the Band A uplink operating band.

The filter 61a is an example of a first filter and is connected between the output terminal of the power amplifier 11a and the input terminal 421 of the transformer 42. Specifically, one end of the filter 61 a is connected to the output end of the power amplifier 11 a, and the other end of the filter 61 a is connected to the input terminal 421 of the transformer 42 .

The filter 61b is an example of a second filter and is connected between the output terminal of the power amplifier 11b and the input terminal 422 of the transformer 42. Specifically, one end of the filter 61b is connected to the output end of the power amplifier 11b, and the other end of the filter 61b is connected to the input terminal 422 of the transformer .

Note that the circuit configuration of the high-frequency circuit 1C in FIG. 6 is an example, and is not limited to this. For example, the transformer 41 may not be included in the high frequency circuit 1C. In this case, two phase-adjusted band A signals may be supplied from the RFIC 3 to the high-frequency circuit 1C.

[4.2 Effects, etc.]
As described above, the high-frequency circuit 1C according to the present embodiment further includes a transformer 42. The transformer 42 has input terminals 421 and 422 and an output terminal 423 connected to the input port 311 of the directional coupler 31. , power amplifier circuit 10C having power amplifiers 11a and 11b, filter circuit 60C having a passband that includes the uplink operating band of band A, and the output of power amplifier 11a and A filter 61a connected between the input terminal 421 of the transformer 42 and having a passband including the uplink operating band of band A, connected between the output of the power amplifier 11b and the input terminal 422 of the transformer 42. and a filter 61b.

According to this, the two power amplifiers 11a and 11b connected in parallel can be used to amplify the transmission signal to a power higher than the first maximum output power. That is, the power amplifiers 11a and 11b can achieve the first maximum output power even if the transmission signal cannot be amplified to a power higher than the first maximum output power. Furthermore, since two filters 61a and 61b connected in parallel are used, the individual power durability of the filters 61a and 61b can be suppressed.

(Embodiment 5)
Next, Embodiment 5 will be described. The present embodiment differs from the first embodiment mainly in that the high-frequency circuit includes two directional couplers. The present embodiment will be described below with reference to FIG. 7, focusing on the differences from the first embodiment.

[5.1 Circuit Configuration of High Frequency Circuit 1D]
FIG. 7 is a circuit configuration diagram of a high-frequency circuit 1D and a communication device 5D according to this embodiment. Note that the communication device 5D is the same as the communication device 5 according to the first embodiment except that the high-frequency circuit 1D is provided instead of the high-frequency circuit 1, so the description is omitted.

The high frequency circuit 1D includes a power amplifier circuit 10, directional couplers 31 and 34, a filter circuit 60, a control circuit 70, an antenna connection terminal 101, a high frequency input terminal 111, a control terminal 131, and an external output terminal. 141 and 142.

In this embodiment, the directional coupler 31 is an example of a first directional coupler, and the input port 311, the output port 312 and the coupling port 313 of the directional coupler 31 are respectively the first input port, It is an example of a first output port and a first coupling port. A coupling port 313 and an isolation port 314 of the directional coupler 31 are not connected to the control circuit 70 .

The directional coupler 34 is an example of a second directional coupler, and can extract part of the power propagating in a specific direction on the path between the power amplifier circuit 10 and the filter circuit 60. Here, the directional coupler 34 is a bidirectional coupler, and extracts part of the forward propagating power (progressive wave) and part of the backward propagating power (reflected wave). be able to.

The directional coupler 34 has an input port 341 , an output port 342 , a coupling port 343 and an isolation port 344 . The input port 341 is an example of a second input port, is a port to which power (traveling wave) is applied, and is connected to the output end of the power amplifier circuit 10 . The coupling port 343 is an example of a second coupling port, is a port to which part of the power (traveling wave) applied to the input port 341 is coupled, and is connected to the control circuit 70 . The output port 342 is an example of a second output port, and is a port that outputs the other part of the power (traveling wave) applied to the input port 341. Through the filter circuit 60 and the directional coupler 31, It is connected to the antenna connection terminal 101 . The isolation port 344 is a port to which part of the power (reflected wave) applied to the output port 342 is coupled, and is connected to the control circuit 70 .

[5.2 Effects, etc.]
As described above, the high-frequency circuit 1D according to the present embodiment includes the power amplifier circuit 10 corresponding to the first power class that allows the first maximum output power that is equal to or higher than the maximum output power allowed in the power class 2, and the power amplifier circuit 10 a filter circuit 60 connected to the output of circuit 10 and having a passband including the band A uplink operating band for frequency division duplexing; directional couplers 31 and 34; and a control circuit for controlling power amplifier circuit 10. 70, the directional coupler 31 has an input port 311 connected to the output terminal of the power amplifier circuit 10 via the filter circuit 60, an output port 312 connected to the antenna connection terminal 101, and an external connection. The directional coupler 34 has an input port 341 connected to the output terminal of the power amplifier circuit 10 and is connected to the antenna connection terminal 101 via the filter circuit 60. and a coupling port 343 connected to the control circuit 70 , and the control circuit 70 limits amplification of the high-frequency signal by the power amplifier circuit 10 based on the first signal from the coupling port 343 . do.

According to this, the control circuit 70 can acquire a signal from the coupling port 343 of the directional coupler 34 connected between the power amplifier circuit 10 and the filter circuit 60 . Therefore, it is possible to more accurately grasp the power of the high-frequency signal input to the filter circuit 60, and to more effectively suppress damage to the filter circuit 60 due to a high-power signal.

Further, for example, in the high-frequency circuit 1D according to the present embodiment, the control circuit 70 may limit the amplification of the high-frequency signal by the power amplifier circuit 10 by stopping the supply of the power supply voltage to the power amplifier circuit 10. .

According to this, since the amplification of the power amplifier circuit 10 is restricted using the power supply voltage, faster feedback control can be realized.

Further, for example, in the high-frequency circuit 1D according to the present embodiment, the control circuit 70 may limit the amplification of the high-frequency signal by the power amplifier circuit 10 by reducing the bias current of the power amplifier circuit 10.

According to this, since the amplification of the power amplifier circuit 10 is limited using the bias current, feedback control can be realized more easily.

Further, for example, in the high-frequency circuit 1D according to the present embodiment, the control circuit 70 limits the amplification of the high-frequency signal by the power amplifier circuit 10 when the power value of the first signal from the coupling port 343 is equal to or greater than the threshold. Alternatively, if the power value of the first signal from the coupling port 343 is less than the threshold, the amplification of the high frequency signal by the power amplifier circuit 10 may not be restricted.

According to this, when the power value of the traveling wave is large, the amplification of the power amplifier circuit 10 can be limited, and when a high frequency signal with an output power exceeding the maximum output power allowed by the high frequency circuit 1D is output, , the amplification of the power amplifier circuit 10 can be limited quickly.

Further, for example, in the high-frequency circuit 1D according to the present embodiment, the directional coupler 34 may further include an isolation port 344 connected to the control circuit 70 , and the control circuit 70 receives the second signal from the coupling port 343 . Amplification of high frequency signals by the power amplifier circuit 10 may be limited based on the 1 signal and the second signal from the isolation port 344 .

According to this, the amplification of the power amplifier circuit 10 is limited based on not only the traveling wave but also the reflected wave, so feedback control based on the power supplied to the directional coupler 34 is possible. Therefore, it is possible to more accurately reflect the power of the high-frequency signal passing through the components on the transmission path (for example, the filter circuit 60, etc.) in the control, and to more effectively suppress damage to the module due to high-power signals. .

Further, for example, in the high-frequency circuit 1D according to the present embodiment, the control circuit 70 determines that the sum of the power value of the first signal from the coupling port 343 and the power value of the second signal from the isolation port 344 is equal to or greater than the threshold. In this case, the amplification of the high frequency signal by the power amplifier circuit 10 may be restricted, and when the sum of the power value of the first signal and the power value of the second signal is less than the threshold, the power amplifier circuit 10 may limit the amplification of the high frequency signal. Amplification need not be limited.

According to this, when the sum of the power value of the forward wave and the power value of the reflected wave is large, the amplification of the power amplifier circuit 10 can be limited, and the components (for example, the filter circuit 60) on the transmission path allow When a high-frequency signal with power exceeding the maximum output power is output, the amplification of the power amplifier circuit 10 can be quickly limited.

Further, the communication device 5D according to the present embodiment includes an RFIC 3 that processes high frequency signals, and a high frequency circuit 1D that transmits high frequency signals between the RFIC 3 and the antenna 2.

According to this, the effect of the high-frequency circuit 1D can be realized in the communication device 5D.

(Other embodiments)
Although the high-frequency circuit, communication device, and communication method according to the present invention have been described above based on the embodiments, the high-frequency circuit, communication device, and communication method according to the present invention are not limited to the above-described embodiments. do not have. Another embodiment realized by combining arbitrary constituent elements in the above embodiment, and a modification obtained by applying various modifications that a person skilled in the art can think of without departing from the scope of the present invention to the above embodiment For example, the present invention also includes various devices incorporating the high-frequency circuit.

For example, in the circuit configuration of the high-frequency circuit and the communication device according to each of the above-described embodiments, even if another circuit element and wiring are inserted between the paths connecting the circuit elements and signal paths disclosed in the drawings. good. For example, an impedance matching circuit may be inserted between the power amplifier circuit 10 and the filter circuit 60 and/or between the filter circuit 60 and the antenna connection terminal 101 .

Also, for example, the first to fifth embodiments may be combined arbitrarily. For example, the switches 32 and 33 in the above second embodiment may be employed in any one of the high frequency circuits 1B to 1D according to the third to fifth embodiments. Moreover, the third and fifth embodiments may be combined. That is, the high-frequency circuit 1D according to the fifth embodiment may further include a filter circuit 602 connected to the output end of the power amplifier circuit 10 and having a passband including band B for time division duplexing. In this case, directional coupler 34 may be connected between power amplifier circuit 10 and filter circuits 60 and 602 .

Although bidirectional couplers are used as the directional couplers 31 and 34 in each of the above embodiments, they are not limited to this. For example, unidirectional couplers may be used as directional couplers 31 and/or 34 . In this case, the directional couplers 31 and/or 34 may not have isolation ports. That is, the isolation port 314 or 344 does not have to be connected to the control circuit 70 and the external output terminal 142 . At this time, the control circuit 70 may not include the preamplifier 701b and the wave detector 702b, and the power calculator 703 may not calculate the supplied power value Ps.

Although the high-frequency circuit 1B and the communication device 5B according to the third embodiment correspond to the bands A and B, the number of bands that can correspond is not limited to two. For example, the high-frequency circuit and communication device may be configured to support band C in addition to bands A and B. Such a high frequency circuit and communication device will be described with reference to FIG.

FIG. 8 is a circuit configuration diagram of a high frequency circuit 1E and a communication device 5E according to another embodiment. Note that the communication device 5E is the same as the communication device 5B according to the third embodiment, except that the communication device 5E further includes an antenna 2E and a high-frequency circuit 1E instead of the high-frequency circuit 1B, so description thereof will be omitted.

The high frequency circuit 1E includes a power amplifier circuit 10B, a power amplifier 12, directional couplers 31 and 35, switches 51E, 52, 53 and 54, filter circuits 601 and 602, a filter 64, and a control circuit 70. , antenna connection terminals 101 and 102, high frequency input terminals 111 and 112, a high frequency output terminal 121, a control terminal 131, and external output terminals 141-143.

The antenna connection terminal 102 is connected to the antenna 2E outside the high frequency circuit 1E.

The high frequency input terminal 112 is an input terminal for receiving a transmission signal of band C from the outside of the high frequency circuit 1E. In this embodiment, the high frequency input terminal 112 is connected to the RFIC 3 outside the high frequency circuit 1E.

The external output terminal 143 is a terminal for supplying a signal to the outside of the high frequency circuit 1E. The external output terminal 143 is connected to the RFIC 3 outside the high frequency circuit 1E. The external output terminal 143 is connected to the coupling port 353 of the directional coupler 35 inside the high frequency circuit 1E.

The power amplifier 12 is connected between the high frequency input terminal 112 and the filter 64, and can amplify the band C transmission signal. The power amplifier 12 supports the second power class and does not need to support the first power class.

The directional coupler 35 can extract part of the power propagating in a specific direction on the path between the filter 64 and the antenna connection terminal 102 . Here, the directional coupler 35 is a unidirectional coupler, and can extract part of the forward propagating power (travelling wave). A bidirectional coupler may be used as the directional coupler 35 . Moreover, the directional coupler 35 may not be included in the high frequency circuit 1E.

The directional coupler 35 has an input port 351 , an output port 352 and a coupling port 353 . The input port 351 is a port to which power (traveling wave) is applied, and is connected to the output terminal of the power amplifier 12 via the filter 64 . A coupling port 353 is a port to which a part of the power (traveling wave) applied to the input port 351 is coupled, and is connected to the external output terminal 143 but not connected to the control circuit 70 . The output port 352 is a port that outputs the other part of the power (traveling wave) applied to the input port 351 and is connected to the antenna connection terminal 102 .

The switch 51E is connected between the antenna connection terminals 101 and 102, the filter circuits 601 and 602, and the filter 63. The switch 51E has terminals 511-515. Terminal 511 is connected to antenna connection terminal 101 via directional coupler 31 . Terminal 512 is connected to filter circuit 601 . Terminal 513 is connected to filter circuit 602 . Terminal 514 is connected to antenna connection terminal 102 via directional coupler 35 . Terminal 515 is connected to filter 64 .

In this connection configuration, the switch 51E can exclusively connect the terminal 511 to the terminals 512 and 513 based on a control signal from the RFIC 3, for example. In addition, switch 51E can connect terminal 514 to terminal 515 exclusively.

The filter 64 is connected between the antenna connection terminal 102 and the power amplifier 12 . Specifically, one end of the filter 64 is connected to the output end of the power amplifier 12, and the other end of the filter 64 is connected to the antenna connection terminal 102 via the switch 51E and the directional coupler 35.

The filter 64 has a passband that includes the band C transmission band. Band C is a frequency band for communication systems built using RATs predefined by standards bodies and the like. Band C may be the frequency band for FDD, the frequency band for TDD, or the SUL (Supplementary Uplink) band.

The present invention can be widely used in communication equipment such as mobile phones as a high-frequency circuit arranged in the front end section.

1, 1A, 1B, 1C, 1D, 1E high frequency circuit 2 antenna 3 RFIC
4 BBIC
5, 5A, 5B, 5C, 5D, 5E Communication Device 10, 10B, 10C Power Amplifier Circuit 11, 11a, 11b, 11B, 12 Power Amplifier 21 Low Noise Amplifier 31, 34, 35 Directional Coupler 32, 33, 51 , 51E, 52, 53, 54 Switches 41, 42 Transformers 60, 60C, 601, 602 Filter circuits 61, 61a, 61b, 62, 63, 64 Filters 70 Control circuits 101, 102 Antenna connection terminals 111, 112 High frequency input terminal 121 High-frequency output terminal 131 Control terminals 141, 142, 143 External output terminals 311, 341 Input ports 312, 342 Output ports 313, 343 Coupling ports 314, 344 Isolation ports 321, 322, 331, 332, 511, 512, 513, 521 , 522, 523, 531, 532, 533, 541, 542, 543 Terminals 411, 421, 422 Input terminals 412, 424 Ground terminals 413, 414, 423 Output terminals 415, 425 Primary coils 416, 426 Secondary coils 701a, 701b Preamplifier 702a, 702b Detector 703 Power calculator 704 Comparator 705 Controller

Claims (19)

1. a power amplifier circuit corresponding to a first power class that allows a first maximum output power that is equal to or higher than the maximum output power allowed in power class 2;
   a first filter circuit connected to the output of the power amplifier circuit and having a passband including a first band uplink operating band for frequency division duplexing;
   a directional coupler;
   a control circuit that controls the power amplifier circuit,
   The directional coupler is
   an input port connected to the output end of the power amplifier circuit via the first filter circuit;
   an output port connected to the antenna connection terminal;
   a coupling port connected to the control circuit and an external connection terminal;
   wherein the control circuit limits amplification of a high frequency signal by the power amplifier circuit based on a first signal from the coupling port;
   high frequency circuit.
2. The control circuit limits the amplification of the high-frequency signal by the power amplifier circuit by stopping the supply of the power supply voltage to the power amplifier circuit.
   A high-frequency circuit according to claim 1.
3. The control circuit limits amplification of the high-frequency signal by the power amplifier circuit by reducing the bias current of the power amplifier circuit.
   3. The high-frequency circuit according to claim 1 or 2.
4. The control circuit limits amplification of the high-frequency signal by the power amplifier circuit when the power value of the first signal is equal to or greater than a threshold, and limits the amplification of the high-frequency signal by the power amplifier circuit when the power value of the first signal is less than the threshold. Do not limit the amplification of high-frequency signals by the power amplifier circuit,
   A high-frequency circuit according to any one of claims 1 to 3.
5. further comprising a first switch connected between said coupling port and said control circuit;
   The first switch is
   connecting the coupling port to the control circuit when the first power class is applied to the transmission of the signal in the first band;
   not connecting the coupling port to the control circuit when a second power class allowing a second maximum output power lower than the first maximum output power is applied for transmission of signals in the first band;
   A high-frequency circuit according to any one of claims 1 to 4.
6. The directional coupler further has an isolation port connected to the control circuit,
   The control circuit limits amplification of a high frequency signal by the power amplifier circuit based on the first signal from the coupling port and the second signal from the isolation port.
   A high-frequency circuit according to any one of claims 1 to 5.
7. The control circuit limits amplification of the high-frequency signal by the power amplifier circuit when the sum of the power value of the first signal and the power value of the second signal is equal to or greater than a threshold, and the power value of the first signal and not limiting the amplification of the high-frequency signal by the power amplification circuit when the sum of the power values of the second signal is less than the threshold;
   A high-frequency circuit according to claim 6.
8. further comprising a second switch connected between the isolation port and the control circuit;
   The second switch is
   connecting the isolation port to the control circuit when the first power class is applied to transmission of the first band signal;
   not connecting the isolation port to the control circuit when a second power class that allows a second maximum output power lower than the first maximum output power is applied to the transmission of the signal in the first band;
   A high-frequency circuit according to claim 6 or 7.
9. The high frequency circuit further comprises a second filter circuit connected to the output end of the power amplifier circuit and having a passband including a second band for time division duplexing.
   A high-frequency circuit according to any one of claims 1 to 8.
10. The high-frequency circuit further comprises a synthesizer,
    The combiner is
    a first input terminal;
    a second input terminal;
    an output terminal connected to the input port;
    The power amplifier circuit is
    a first power amplifier;
    a second power amplifier;
    The first filter circuit is
    a first filter having a passband that includes the first band of uplink operating bands and connected between the output of the first power amplifier and the first input of the combiner;
    a second filter having a passband that includes the first band of uplink operating bands and connected between the output of the second power amplifier and the second input of the combiner;
    A high-frequency circuit according to any one of claims 1 to 9.
11. a signal processing circuit that processes high frequency signals;
    A high-frequency circuit according to any one of claims 1 to 10, which transmits the high-frequency signal between the signal processing circuit and the antenna,
    Communication device.
12. a power amplifier circuit corresponding to a first power class that allows a first maximum output power that is equal to or higher than the maximum output power allowed in power class 2;
    a first filter circuit connected to the output of the power amplifier circuit and having a passband including a first band uplink operating band for frequency division duplexing;
    a first directional coupler and a second directional coupler;
    a control circuit that controls the power amplifier circuit,
    The first directional coupler is
    a first input port connected to the output terminal of the power amplifier circuit via the first filter circuit;
    a first output port connected to the antenna connection terminal;
    a first coupling port connected to the external connection terminal;
    The second directional coupler is
    a second input port connected to the output terminal of the power amplifier circuit;
    a second output port connected to the antenna connection terminal via the first filter circuit;
    a second coupling port connected to the control circuit;
    wherein the control circuit limits amplification of a high frequency signal by the power amplifier circuit based on a first signal from the second coupling port;
    high frequency circuit.
13. The control circuit limits the amplification of the high-frequency signal by the power amplifier circuit by stopping the supply of the power supply voltage to the power amplifier circuit.
    A high frequency circuit according to claim 12.
14. The control circuit limits amplification of the high-frequency signal by the power amplifier circuit by reducing the bias current of the power amplifier circuit.
    14. The high frequency circuit according to claim 12 or 13.
15. The control circuit limits amplification of the high-frequency signal by the power amplifier circuit when the power value of the first signal is equal to or greater than a threshold, and limits the amplification of the high-frequency signal by the power amplifier circuit when the power value of the first signal is less than the threshold. Do not limit the amplification of high-frequency signals by the power amplifier circuit,
    The high-frequency circuit according to any one of claims 12-14.
16. The second directional coupler further has an isolation port connected to the control circuit,
    The control circuit limits amplification of a high frequency signal by the power amplifier circuit based on the first signal from the second coupling port and the second signal from the isolation port.
    The high-frequency circuit according to any one of claims 12-15.
17. The control circuit limits amplification of the high-frequency signal by the power amplifier circuit when the sum of the power value of the first signal and the power value of the second signal is equal to or greater than a threshold, and the power value of the first signal and not limiting the amplification of the high-frequency signal by the power amplification circuit when the sum of the power values of the second signal is less than the threshold;
    17. A high frequency circuit according to claim 16.
18. The high frequency circuit further comprises a second filter circuit connected to the output end of the power amplifier circuit and having a passband including a second band for time division duplexing.
    The high-frequency circuit according to any one of claims 12-17.
19. a signal processing circuit that processes high frequency signals;
    The high-frequency circuit according to any one of claims 12 to 18, which transmits the high-frequency signal between the signal processing circuit and the antenna,
    Communication device.

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