JP2000082780A - Communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication device which can be reduced in size and stabilized in operation and can be manufactured by a simplified manufacturing process. SOLUTION: A broadcast radio receiver 100 is for receiving an FM broadcast. It is constituted of a semiconductor chip 10 for receiving, a quartz oscillator 40, a stereophonic demodulation circuit 50, an audio adjusting section 60, a power amplifier 70, a speaker 80, and an antenna 90. The semiconductor chip 10 for receiving has a high frequency analog circuit 20 and a frequency synthesizer 30, which are formed on a single semiconductor substrate into a single chip and therefore are handled as one component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication device for transmitting and receiving various signals using a frequency synthesizer.

[0002]

2. Description of the Related Art In radio broadcasting, a broadcasting station sends
A signal obtained by modulating an audio signal using a modulation method such as modulation or FM modulation is transmitted. For this reason, the radio receiver demodulates the received signal according to the modulation method, and performs audio output from the speaker by performing volume adjustment and the like.

FIG. 7 is a diagram showing a configuration of a conventional radio receiver. A radio receiver 500 shown in FIG. 1 is a radio receiver using a superheterodyne system, and is a high-frequency analog circuit 5 that performs a predetermined reception process on a broadcast signal.
10 and a frequency synthesizer 52 for outputting a local oscillation signal mixed with the broadcast signal and controlling its frequency.
0, a crystal oscillator 530 connected to the frequency synthesizer 520, and a stereo demodulation circuit 540 for demodulating an L signal (left audio signal) and an R signal (right audio signal) from a composite signal output from the high frequency analog circuit 510. , An audio adjustment unit 550 that adjusts the volume and sound quality of the L signal and the R signal, a power amplifier 560 that amplifies and outputs the L signal and the R signal according to the volume adjustment by the audio adjustment unit 550, and performs audio output. It is configured to include a speaker 570 and an antenna 580 for receiving a broadcast signal. The user can listen to a desired broadcast by instructing the radio receiver 500 to select a channel or adjust the volume.

[0004]

The high-frequency analog circuit 510 constituting the radio receiver 500 described above.
The frequency synthesizer 520 and the like are manufactured and sold as separate functional components, and the radio receiver 500 is assembled by combining these components.

[0005] However, since the high-frequency analog circuit 510, the frequency synthesizer 520, and the like are separate functional components, the area required for assembling these components increases. In particular, portable radio receivers are required to be as small as possible, but an increase in the area required for assembly has hindered miniaturization. If the signal line connecting the high-frequency analog circuit 510 and the frequency synthesizer 520 is long or arranged close to other signal lines, noise is mixed into the signal line, and the high-frequency analog circuit 510 Sometimes became unstable. Furthermore, since the manufacturer of the radio receiver 500 assembles the high-frequency analog circuit 510 and the frequency synthesizer 520 respectively, there is a problem that the manufacturing process becomes complicated and the number of steps increases.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a communication device capable of miniaturizing, stabilizing operation, and simplifying a manufacturing process.

[0007]

In order to solve the above-mentioned problems, a communication apparatus according to the present invention includes a high-frequency analog circuit for performing a predetermined receiving operation involving a frequency conversion process on an input signal, and a frequency conversion process. A frequency synthesizer that outputs an oscillation signal to be used and controls the frequency is integrally formed on a single semiconductor substrate. By integrally forming the high-frequency analog circuit and the frequency synthesizer on a semiconductor substrate, the area required for assembling components is reduced, so that the communication device can be downsized. Also,
The signal line connecting the high-frequency analog circuit and the frequency synthesizer is shortened, and noise mixed in this signal line can be suppressed, and the operation of the high-frequency analog circuit can be stabilized. Furthermore, since the high-frequency analog circuit and the frequency synthesizer can be assembled as a single component, the number of components at the time of assembly is reduced, and the manufacturing process can be simplified.

Further, in the communication apparatus of the present invention, a high-frequency analog circuit for performing a predetermined transmission operation involving a frequency conversion process on an input signal, and outputs an oscillation signal used for the frequency conversion process and controls the frequency thereof. The frequency synthesizer and the frequency synthesizer are integrally formed on a single semiconductor substrate. Also in this case, the area required for assembling the components is reduced, so that the communication device can be downsized. In addition, the signal line connecting the high-frequency analog circuit and the frequency synthesizer is shortened, suppressing noise mixed in this signal line,
The operation of the high-frequency analog circuit can be stabilized.
Furthermore, since the high-frequency analog circuit and the frequency synthesizer can be assembled as a single component, the number of components at the time of assembly is reduced, and the manufacturing process can be simplified.

Particularly, when a guard ring for noise reflection is formed between the high-frequency analog circuit and the frequency synthesizer, the noise generated from the frequency synthesizer is suppressed from being mixed into the high-frequency analog circuit. The operation of the circuit can be further stabilized.
Further, the high-frequency analog circuit and the frequency synthesizer may be arranged apart from each other by a predetermined distance. Also in this case, it is possible to suppress noise generated from the frequency synthesizer from being mixed into the high-frequency analog circuit, and to further stabilize the operation of the high-frequency analog circuit.

Further, a shield member for preventing external noise from being mixed may be provided, and a high-frequency analog circuit and a frequency synthesizer integrally formed may be arranged inside the shield member. Since the shield member prevents external noise from being mixed in, the operation of the high-frequency analog circuit can be further stabilized.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A radio receiver according to an embodiment of the present invention includes a high-frequency analog circuit for performing a predetermined receiving operation such as a demodulation process and a frequency synthesizer for outputting a local oscillation signal and controlling the frequency thereof. It is characterized by being integrally formed on a single semiconductor substrate. Hereinafter, a radio receiver according to an embodiment will be described with reference to the drawings.

FIG. 1 is a diagram showing the overall configuration of a radio receiver. A radio receiver 100 shown in FIG. 1 is for receiving an FM broadcast, and includes a semiconductor chip 10 for reception,
It includes a crystal unit 40, a stereo demodulation circuit 50, an audio adjustment unit 60, a power amplifier 70, a speaker 80, and an antenna 90.

The receiving semiconductor chip 10 has a high-frequency analog circuit 20 and a frequency synthesizer 30 formed on a single semiconductor substrate such as silicon. That is, the high-frequency analog circuit 20 and the frequency synthesizer 30 are integrated into one chip, and are treated as a single component. Therefore, the area required for assembling the high-frequency analog circuit 20 and the frequency synthesizer 30 is reduced. Further, a signal line connecting the high-frequency analog circuit 20 and the frequency synthesizer 30 is shortened, and noise mixed in the signal line can be suppressed. Further, the high frequency analog circuit 20 and the frequency synthesizer 30 can be assembled as a single component.

The high frequency analog circuit 20 receives a predetermined FM broadcast signal and performs demodulation processing and the like, and includes a high frequency receiving circuit 21, a frequency conversion circuit 22, an intermediate frequency amplification circuit 23, and a detection circuit 24. Have been.

The high-frequency receiving circuit 21 includes an antenna tuning circuit and a high-frequency amplifier circuit, performs high-frequency amplification on the FM broadcast signal input from the antenna 90, and outputs the amplified FM broadcast signal.

The high frequency receiving circuit 2
By mixing the amplified FM broadcast signal output from 1 with the local oscillation signal output from the frequency synthesizer 30, an intermediate frequency signal obtained by converting the frequency of the FM broadcast signal is output. For example, when a desired FM broadcast signal to be received is input to the frequency conversion circuit 22, the signal is mixed with a local oscillation signal output from the frequency synthesizer 30 to convert the signal into an intermediate frequency signal of 10.7 MHz. .

The intermediate frequency amplifier 23 amplifies the intermediate frequency signal output from the frequency converter 22 and
A tuning operation for extracting only a signal near 0.7 MHz is performed. The detection circuit 24 performs FM detection on the amplified intermediate frequency signal output from the intermediate frequency amplification circuit 23 and outputs a composite signal. As a specific FM detection method, for example, there is a method in which a change in frequency of an intermediate frequency signal is temporarily converted into a change in amplitude, and AM detection is performed on the converted signal.

The frequency synthesizer 30 is for controlling and outputting the frequency of a local oscillation signal, and includes a voltage controlled oscillator (VCO) 31 for outputting a local oscillation signal,
A frequency divider 32 having a frequency division ratio N for dividing the local oscillation signal output from the CO 31, a reference oscillator 33 for outputting a reference frequency signal determined by the crystal oscillator 40, a divided local oscillation signal and a reference frequency The phase comparator 34 includes a phase comparator 34 for comparing a phase with a signal, and a low-pass filter (LPF) 35 for outputting a DC voltage for controlling the VCO 31 in accordance with a result of the phase comparison by the phase comparator 34.

The operation of the frequency synthesizer 30 is as follows. For example, when the VCO 31 needs to output a local oscillation signal having a frequency of N × fr,
When 31 outputs a local oscillation signal of frequency fosc, frequency divider 32 divides this local oscillation signal into a signal of frequency fosc / N and outputs the signal to phase comparator 34. On the other hand, the reference oscillator 33 outputs a reference frequency signal having a frequency fr determined by the crystal unit 40 to the phase comparator 34. The phase comparator 34 outputs the frequency fosc / N output from the frequency divider 32.
Is compared with the signal of the frequency fr output from the reference oscillation 33 to determine the phase difference, and output a signal having a duty ratio according to the comparison result. The LPF 35 feeds back a DC control voltage corresponding to the signal output from the phase comparator 34 to the VCO 31. The VCO 31 controls fosc / N and f
The oscillation frequency is changed so that r becomes equal, that is, fosc becomes equal to N × fr, and the frequency N × fr
Output the local oscillation signal.

The stereo demodulation circuit 50 demodulates the L signal and the R signal from the composite signal output from the detection circuit 24. The audio adjustment unit 60 includes the stereo demodulation circuit 5
The volume and sound quality of the L signal and the R signal output from 0 are adjusted. Specifically, the audio adjustment unit 60 adjusts the volume of the L signal and the R signal by changing the gain of the power amplifier 70 at the subsequent stage. The audio adjustment unit 60 includes a built-in variable resistor for sound quality adjustment (not shown).
, The sound quality of the L signal and the R signal is adjusted. The power amplifier 70 outputs the L signal and the R signal in accordance with the gain adjusted by the audio adjustment unit 60.
Amplify the signal. These amplified L and R signals are output as audio from the speaker 80.

As described above, the radio receiver 1 of the present embodiment
In the reference numeral 00, the high-frequency analog circuit 20 and the frequency synthesizer 30 constitute the receiving semiconductor chip 10. That is, the high-frequency analog circuit 20 and the frequency synthesizer 30 are integrated into one chip. By integrating the high-frequency analog circuit 20 and the frequency synthesizer 30 into one chip, the area required for assembling the components is reduced as compared with the conventional case where the high-frequency analog circuit 20 and the frequency synthesizer 30 are separate functional parts. Therefore, the size of the radio receiver 100 can be reduced. Also,
By using one chip, the signal line connecting the high-frequency analog circuit 20 and the frequency synthesizer 30 is shortened, and noise mixed in this signal line can be suppressed, and the operation of the high-frequency analog circuit 20 can be stabilized. Further, the high-frequency analog circuit 20 and the frequency synthesizer 30
Can be assembled as a single part, the number of parts at the time of assembly is reduced, and the manufacturing process can be simplified.

In the above-described embodiment, the positional relationship between the high-frequency analog circuit 20 and the frequency synthesizer 30 constituting the receiving semiconductor chip 10 is not particularly considered. For example, the receiving semiconductor chip shown in FIG. 1
As in 1, the guard ring 12 for noise reflection may be formed between the high-frequency analog circuit 20 and the frequency synthesizer 30. By forming the guard ring 12, noise generated from the frequency synthesizer 30 can be suppressed from being mixed into the high-frequency analog circuit 20, and the operation of the high-frequency analog circuit 20 can be further stabilized.

The receiving semiconductor chip 13 shown in FIG.
As described above, the high-frequency analog circuit 20 and the frequency synthesizer 30 may be arranged at a predetermined distance from each other. By arranging them at a predetermined distance, noise generated from the frequency synthesizer 30 is prevented from entering the high-frequency analog circuit 20, and the operation of the high-frequency analog circuit 20 can be further stabilized.

The receiving semiconductor chip 14 shown in FIG.
As described above, a shield member 15 such as a resin mold for preventing noise from entering from the outside may be provided, and the high-frequency analog circuit 20 and the frequency synthesizer 30 may be arranged inside the shield member 15. Since the noise from the outside is prevented by the shield member 15, the operation of the high-frequency analog circuit 20 can be further stabilized.

In the embodiment described above, only the high-frequency analog circuit 20 and the frequency synthesizer 30 are integrated into one chip. However, as in the radio receiver 200 shown in FIG. The receiving semiconductor chip 16 may include the stereo demodulation circuit 50 and the audio adjustment unit 60. Since the stereo demodulation circuit 50 and the audio adjustment unit 60 are also integrally formed on a single semiconductor substrate, the high-frequency analog circuit 20, the frequency synthesizer 30, the stereo demodulation circuit 50, the audio adjustment unit 6
Since 0 is integrated into one chip, the area required for assembling the components is further reduced, and the radio receiver 200 can be further reduced in size. Further, since the stereo demodulation circuit 50 and the audio adjustment unit 60 connected to the subsequent stage of the high-frequency analog circuit 20 are integrated into one chip, the operation of the high-frequency analog circuit 20 can be further stabilized. Further, the high-frequency analog circuit 20, the frequency synthesizer 3
0, the stereo demodulation circuit 50 and the audio adjustment unit 60 can be assembled as a single component, so that the manufacturing process can be further simplified.

In the above-described embodiment, the LPF 35 is built in the semiconductor chips 10 and 16 for reception.
When the area occupied by the capacitor included inside 35 increases (when a large time constant is required), LPF 3
5 may be connected to the outside of the receiving semiconductor chips 10 and 16.

In the above-described embodiment, a radio receiver for receiving an FM broadcast is used as a communication device.
Other media, such as a radio receiver that receives other broadcasts other than FM broadcasts such as M broadcasts and PCM broadcasts, a radio receiver that can receive both FM broadcasts and AM broadcasts, and a television receiver, are set as reception targets. The present invention can be applied to a receiver or a receiver that receives a signal other than a broadcast signal. In these cases, the receiving semiconductor chip may be constituted by at least a high-frequency analog circuit for receiving each broadcast signal and a frequency synthesizer.

The present invention can be similarly applied to a transmitter for transmitting various signals. FIG. 6 is a diagram showing a partial configuration of a transmitter according to an embodiment to which the present invention is applied. The transmitter 300 shown in FIG. 6 is a portion obtained by extracting a portion of a mobile telephone that performs transmission processing, and includes a transmission semiconductor chip 310, a crystal oscillator 340, a transmission power amplifier 350, and an antenna 360. .

The transmitting semiconductor chip 310 has a high-frequency analog circuit 320 and a frequency synthesizer 330 formed on a single semiconductor substrate. That is, the high-frequency analog circuit 320 and the frequency synthesizer 330 are integrated into one chip, and are treated as a single component. Therefore, similarly to the radio receiver 100 shown in FIG. 1, the transmitter 300 can be downsized, the operation of the high-frequency analog circuit 320 can be stabilized, and the manufacturing process of the transmitter 300 can be simplified.

The high-frequency analog circuit 320 performs a modulation process or the like on an audio signal output from a transmitter (not shown). The transmission signal processing circuit 321 and the modulator 32
2. It includes a frequency conversion circuit 323.

The transmission signal processing circuit 321 performs various signal processing such as amplitude limiting processing on the audio signal output from the transmitter, and outputs a baseband signal. Modulator 32
2 modulates a predetermined high-frequency signal with the baseband signal. The frequency conversion circuit 323 mixes the modulated high-frequency signal output from the modulator 322 with the oscillation signal output from the frequency synthesizer 330 to convert the frequency of the high-frequency signal to a predetermined frequency (for example, 80
The signal is converted to a frequency of 0 MHz band or 1.5 GHZ band, and a signal (transmission signal) after the frequency conversion is output.

The frequency synthesizer 330 has the same configuration as the frequency synthesizer 30 shown in FIG.
It includes a VCO 331, a frequency divider 332, a reference oscillator 333, a phase comparator 334, and an LPF 335. The frequency synthesizer 330 performs a phase comparison between a signal obtained by dividing the oscillation signal output from the VCO 331 and a reference frequency signal determined by the crystal oscillator 340, and outputs the VCO according to the comparison result.
By changing the control voltage applied to 331,
The frequency of the oscillation signal output from the VCO 331 is controlled.

The transmission power amplifier 350 amplifies the power of the transmission signal output from the frequency conversion circuit 323. The power-amplified transmission signal is transmitted from antenna 360 to the base station.

As described above, the transmitter 300 of the present embodiment
Is a high-frequency analog circuit 320 and a frequency synthesizer 3
The transmission semiconductor chip 310 is constituted by 30. That is, the high-frequency analog circuit 320 and the frequency synthesizer 330 are integrated into one chip. Therefore, similarly to the radio receiver 100 shown in FIG. 1, the area required for assembling the components is reduced, and the transmitter 300 can be reduced in size. In addition, the high frequency analog circuit 320 and the frequency synthesizer 3
The signal line connecting the signal line 30 to the signal line 30 is shortened, and noise mixed in the signal line is suppressed, and the operation of the high-frequency analog circuit 320 can be stabilized. Further, since the high-frequency analog circuit 320 and the frequency synthesizer 330 can be assembled as a single component, the number of components at the time of assembly is reduced, and the manufacturing process can be simplified.

[0035]

As described above, according to the present invention, the high-frequency analog circuit and the frequency synthesizer are integrally formed on a single semiconductor substrate, and the area required for assembling the components is reduced. The device can be downsized. Further, a signal line connecting the high-frequency analog circuit and the frequency synthesizer is shortened, and noise mixed in this signal line can be suppressed, and the operation of the high-frequency analog circuit can be stabilized. Furthermore, since the high-frequency analog circuit and the frequency synthesizer can be assembled as a single component, the number of components at the time of assembly is reduced, and the manufacturing process can be simplified.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of a radio receiver according to an embodiment.

FIG. 2 is a diagram showing a receiving semiconductor chip on which a guard ring is arranged.

FIG. 3 is a diagram showing a receiving semiconductor chip in which a high-frequency analog circuit and a frequency synthesizer are formed separately.

FIG. 4 is a diagram showing a receiving semiconductor chip in which a high-frequency analog circuit and a frequency synthesizer are arranged inside a shield member.

FIG. 5 is a diagram illustrating an overall configuration of a radio receiver in which a stereo demodulation circuit and an audio adjustment unit are formed on a receiving semiconductor chip together with a high-frequency analog circuit and a frequency synthesizer.

FIG. 6 is a diagram illustrating a partial configuration of a transmitter according to an embodiment.

FIG. 7 is a diagram showing an overall configuration of a conventional radio receiver.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Receiving semiconductor chip 20 High frequency analog circuit 30 Frequency synthesizer 31 Voltage controlled oscillator (VCO) 40 Crystal oscillator 50 Stereo demodulation circuit 60 Audio adjustment unit 70 Power amplifier 80 Speaker 90 Antenna 100 Radio receiver

Claims (5)

[Claims] 1. A high-frequency analog circuit that performs a predetermined receiving operation involving a frequency conversion process on an input signal, and a frequency synthesizer that outputs an oscillation signal used for the frequency conversion process and controls the frequency thereof. A communication device, wherein the high-frequency analog circuit and the frequency synthesizer are integrally formed on a single semiconductor substrate. 2. A high-frequency analog circuit that performs a predetermined transmission operation involving a frequency conversion process on an input signal, and a frequency synthesizer that outputs an oscillation signal used for the frequency conversion process and controls the frequency thereof. A communication device, wherein the high-frequency analog circuit and the frequency synthesizer are integrally formed on a single semiconductor substrate. 3. The communication device according to claim 1, wherein a guard ring is formed between the high-frequency analog circuit and the frequency synthesizer. 4. The communication device according to claim 1, wherein the high-frequency analog circuit and the frequency synthesizer are arranged at a predetermined distance from each other. 5. The device according to claim 1, further comprising: a shield member for preventing external noise from being mixed, wherein the high-frequency analog circuit and the frequency synthesizer are arranged inside the shield member. Communication device.