JP2010057012A - Device of amplifying distortion correction - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that failure cannot be detected when failure such as poor connection or device failure occurs in a path between a directional coupler 5 and a circulator 7 because a means for detecting the failure is not provided, though an isolator is inserted between the directional coupler 5 and the circulator 7 to prevent a malfunction in distortion correction due to interfering waves such as other carriers which come from an antenna 9. <P>SOLUTION: A device 1 of amplifying distortion correction for amplifying a transmission high-frequency signal subjected to up-conversion of transmission data 15 by a power amplifier 4 and for output of it from the antenna 9 includes the directional coupler 5, a first circulator 6, and a second circulator 7 inserted between the amplifier 4 and the antenna 9, and reflected wave detecting circuits 12 to 14 to be connected to each port of the directional coupler 5, the first circulator 6, and the second circulator 7 from which each reflected wave is taken out. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a distortion compensation amplifying apparatus, and more particularly to a distortion compensation amplifying apparatus that can easily detect a failure without increasing a transmission loss of an output unit when a failure occurs in a signal transmission path.

  In recent years, the progress of digital television and mobile phones has been remarkable and rapidly spreading. Broadcasting equipment used in these broadcasting systems, broadcasting equipment such as relay stations, or broadcasting equipment used in other wireless systems are required to have high reliability. When a failure occurs, this failure is detected quickly. It is desired to respond quickly. Also, as a broadcasting facility, a distortion compensation amplifying apparatus that compensates for a distortion component generated by a signal amplifier is used in order to maintain a high quality signal to be transmitted. This distortion compensation amplifying apparatus also has a function for preventing the distortion compensation from malfunctioning due to interference waves such as other carriers mixed from the antenna in order to correctly compensate the distortion component generated by its own amplification action.

  An example of a conventional distortion compensation amplifying apparatus is shown in FIG. 5 disclosed in Japanese Patent Laid-Open No. 2006-197545 (Patent Document 1) (hereinafter referred to as Prior Art 1). In the distortion compensation amplification apparatus 100 shown in FIG. 5, 101 is a digital predistortion signal processing unit (DPD signal processing unit), 3 is an amplitude / phase modulator (analog quadrature modulator), and 4 is a power amplification unit (AMP). , 102 is a directional coupler (coupler), 103 is an isolator, 7 is a circulator, 8 is a duplexer (DUP), 9 is an antenna, 10 is a directional coupler (coupler), 11 is a distortion detection circuit (distortion DET), Reference numeral 12 denotes a reflected wave detection circuit, 20 denotes a DPD calculation unit, 21 denotes a multicarrier modulation wave IQ generation unit, 22 denotes a distortion compensation calculation unit, 23 denotes a distortion wave monitoring unit, and 24 denotes a reflection wave calculation unit.

The DPD signal processing unit 101 receives the transmission data 15 and includes a DPD calculation unit 20, a distortion monitoring unit 23, and a reflected wave calculation unit 24. The DPD calculation unit 20 further generates a multicarrier IQ modulated wave signal. The multi-carrier modulation wave IQ generation unit 21 and a distortion compensation calculation unit 22 that performs an operation of compensating for distortion of transmission signal power detected by the distortion detection circuit 11 are configured.
The reflected wave calculation unit 24 detects the reflected wave level from the antenna 9 of the transmission signal power. At this time, an interference wave may be mixed into the antenna 9 from another antenna.

  Transmission data generated as IQ data (orthogonal data) by the DPD signal processing unit 101 is subjected to orthogonal modulation and frequency conversion (UP-CONV) into a high frequency signal by the amplitude / phase modulator 3. A transmission high-frequency signal that is a UP-CONV multi-carrier modulation wave is input to the power amplifying unit 4 and amplified to a predetermined output.

  The directional coupler 102 is for branching out and taking out a part of the power of the power-amplified transmission high-frequency signal that is the output of the power amplifier 4. The extracted power is further output to the distortion detection circuit (distortion DET) 11 for monitoring the output power and the distortion wave monitoring unit 23 for monitoring the distortion wave, using the directional coupler 10. A distortion component included in the transmission high-frequency signal power generated during the amplification process is detected and monitored.

  The isolator 103 receives the transmission high-frequency signal power that is the output of the directional coupler 5 in the traveling direction, and outputs it with almost no attenuation.

  The distortion detection circuit 11 converts the transmission high-frequency signal component branched by the directional couplers 102 and 10 and the distortion component (third order, fifth order, seventh order, etc.) included in the transmission high-frequency signal component into low-frequency signals. (DOWN-CONV), the band is limited and the analog / digital converter (A / D) captures the output signal. The output signal is sent to the distortion compensation calculation unit 22 of the DPD signal processing unit 2.

  The circulator 7 has three terminals, and the transmission high-frequency signal power from the isolator 103 side is allowed to pass to the duplexer 8 side without being attenuated, while the backward signal is attenuated to substantially prevent the signal from passing. Further, the reflected wave and the interference wave from the duplexer 8 side are allowed to pass through the reflected wave detection circuit 12 without being attenuated.

  In order to calculate the ratio of traveling wave power to reflected wave power (VSWR), the reflected wave detection circuit 12 limits the band after DOWN-CONV and imports it into the A / D to detect the reflected wave level.

  The transmission high-frequency signal power input to the duplexer 8 is passed through a band-pass filter having a predetermined frequency band, and is output as a transmission-limited high-frequency signal power having a limited bandwidth. The transmission high-frequency signal power output from the duplexer 8 is supplied to the antenna (ANT) 9 via the terminal at the specified output end, and is radiated from the antenna (ANT) 9 as the transmission-limited high-frequency signal power of the band-limited specified output. .

In the distortion compensation amplifying device of the prior art 1 having the circuit configuration as described above, the impedance matching of the transmission line cannot be performed when a connection failure or a failure such as equipment occurs in the line between the duplexer 8 and the antenna 9, and the transmission high frequency Most of the signal power is reflected, and the reflected wave to the reflected wave detection circuit 12 increases. In this prior art 1, when such a failure occurs, the autocorrelation value and the cross-correlation value between the transmission high-frequency signal and the return signal that is the reflected wave are obtained, and the failure of the distortion compensation amplification device is detected.
JP 2006-197545 A

  By the way, in the above prior art, the isolator 103 is inserted between the directional coupler 102 and the circulator 7 in order to prevent the distortion compensation from malfunctioning due to interference waves such as other carriers mixed from the antenna 9. In the above prior art 1, it is possible to detect a failure of the distortion compensation amplifying apparatus 100 when a connection failure or a failure of a device or the like occurs in the line between the duplexer 8 and the antenna 9. When a connection failure or a failure such as a device occurs, there is a problem that the failure cannot be detected because there is no means for detecting this failure. A directional coupler can be inserted on the output side of the isolator 103 of FIG. 5 to monitor the output power and detect a failure by the output power monitor. However, in the case of a directional coupler, there is a problem that the transmission loss increases by about 0.5 dB and the efficiency of the distortion compensation amplifying device deteriorates.

  In view of the above problems, an object of the present invention is to provide a distortion compensation amplification device that can easily detect a failure when a connection failure or a failure occurs in a device or the like in a signal transmission path without increasing transmission loss on the output side. It is to provide.

  The gist of the invention according to the present invention is a distortion compensation amplifying apparatus that amplifies a transmission high-frequency signal obtained by up-converting transmission data by an amplifier and outputs the amplified signal from an antenna, and a directional coupler inserted in the transmission path of the amplifier and the antenna The first circulator, the second circulator, and the directional coupler, the first circulator, and the reflected wave detection circuit connected to the port from which the reflected wave is taken out of the second circulator. It exists in the distortion compensation amplifying apparatus.

  According to the present invention, in the signal transmission path, it is possible to easily detect a failure when a connection failure or a failure occurs in a device without increasing the transmission loss on the output side.

  Next, the best mode for carrying out the present invention will be specifically described with reference to the drawings.

(First embodiment)
FIG. 1 shows a circuit configuration of a distortion compensation amplifying apparatus 1 according to a first embodiment of the present invention. In the present embodiment, a three-port circulator 6 is used in place of the isolator 103 of the prior art 1 shown in FIG. 5, and a directional coupler that extracts a part of the traveling wave from only the coupling port 51 of the prior art 1. Instead of the (coupler) 102, a directional coupler (coupler) 5 for taking out a reflected wave from the circulator 7 side also from the isolation port 52 is used. The first port of the three-port circulator 6 is a transmission high-frequency signal power input port, the second port is a transmission high-frequency signal power output port, and the third port is a reflected wave output port that outputs a return signal from the circulator 7 side. Yes.

  Thereby, when the reflected wave returns to the circulator 6 from the circulator 7 side, this reflected power is output from the third port of the circulator 6, and this reflected power is detected by the reflected wave detection circuit 13. Further, when the reflected wave returns from the circulator 6 side to the directional coupler (coupler) 5, the reflected power is output from the isolation port 52 of the directional coupler (coupler) 5, and the reflected power is reflected from the reflected wave detection circuit. 14 is detected. According to the present embodiment, it is possible to detect a connection failure between the directional coupler 102 and the circulator 7 or a failure such as a device that could not be detected by the prior art 1.

  Hereinafter, the configuration and operation of the distortion compensation amplifying apparatus 1 according to the first embodiment of the present invention will be described in more detail with reference to FIGS. In FIG. 1, 2 is a digital predistortion signal processor (DPD signal processor), 3 is an amplitude / phase modulator (analog quadrature modulator), 4 is a power amplifier (AMP), and 5 is a directional coupler (coupler). ), 6 and 7 are circulators, 8 is a duplexer (DUP), 9 is an antenna, 10 is a directional coupler (coupler), 11 is a distortion detection circuit (distortion DET), 12 to 14 are reflected wave detection circuits, and 20 is A digital predistortion calculation unit (DPD calculation unit), 21 is a multicarrier modulated wave IQ generation unit, 22 is a distortion compensation calculation unit, 23 is a distortion wave monitoring unit, and 25 is a reflected wave calculation unit.

  The DPD signal processing unit 2 receives the transmission data 15 and includes a DPD calculation unit 20, a distorted wave monitoring unit 23, and a reflected wave calculation unit 25. The DPD calculation unit 20 further generates a multicarrier IQ modulated wave signal. The multi-carrier modulation wave IQ generation unit 21 and the distortion compensation calculation unit 22 that performs the operation of compensating the distortion of the transmission high-frequency signal power detected by the distortion detection circuit 11 are configured. The reflected wave calculation unit 25 detects the reflected wave level from the reflected wave detection circuits 12 to 14 and identifies the position of the failure location. At this time, an interference wave from another antenna may be mixed in the reflected wave.

  Transmission data generated as IQ data (orthogonal data) by the DPD signal processing unit 2 is subjected to orthogonal modulation and frequency conversion (UP-CONV) into a high frequency signal by the amplitude / phase modulator 3. A transmission high-frequency signal that is a UP-CONV multi-carrier modulation wave is input to the power amplifying unit 4 and is amplified to a predetermined output.

  The directional coupler 5 is for extracting a part of the power-amplified transmission high-frequency signal, which is the output of the power amplifier 4, into a traveling wave and a reflected wave, and the traveling wave is amplified. The distortion component included in the transmitted high-frequency signal is extracted from the coupling port 51 to the directional coupler 10, and the reflected wave from the circulator 6 side is extracted from the isolation port 52 to the reflected wave detection circuit 14.

  The electric power extracted from the coupling port 51 of the directional coupler 5 is further output to a distortion detection circuit (distortion DET) 11 for monitoring output power using the directional coupler 10.

  The distortion detection circuit 11 converts the transmission high-frequency signal component attenuated and branched by the directional coupler 5 and distortion components (third-order, fifth-order, seventh-order, etc.) contained in the transmission high-frequency signal component into low-frequency signals. It is converted (DOWN-CONV), band-limited, and captured by an analog / digital converter (A / D). The output signal is sent to the distortion compensation calculation unit 22 of the DPD signal processing unit 2.

  Further, the directional coupler 10 outputs power for monitoring the distorted wave to the distorted wave monitoring unit 23. The distorted wave monitoring unit 23 detects and monitors a distortion component included in the transmission high-frequency signal generated during the amplification process based on the transmission high-frequency signal from the directional coupler 10.

  The reflected wave extracted from the isolation port 52 of the directional coupler 5 is DOWN-CONV by the reflected wave detection circuit 14 and then band-limited and taken into A / D, and the reflected wave level is reflected by the reflected wave calculation unit 25. Is detected.

  The circulator 6 has three ports and substantially attenuates the transmission high-frequency signal power with respect to the traveling wave from the directional coupler (coupler) 5 side (first port) to the circulator 7 side (second port). The reflected wave in the opposite direction is substantially blocked. In addition, the reflected high-frequency signal power is allowed to pass through the reflected wave from the circulator 7 side (second port) to the reflected wave detection circuit 13 side (third port) with almost no attenuation, and in the opposite direction. Shut off. The reflected wave detection circuit 13 limits the band of the extracted reflected wave after DOWN-CONV, captures it to the A / D, and the reflected wave calculation unit 25 detects the reflected wave level.

  The circulator 7 has three ports, the transmission high-frequency signal power from the circulator 6 side (first port) is passed through the duplexer 8 side without being attenuated, the reverse signal is attenuated, and the signal is substantially blocked. To do. Further, the reflected wave and the interference wave from the duplexer 8 side (second port) are allowed to pass through the reflected wave detection circuit 12 side (third port) without being attenuated, and are substantially blocked in the opposite direction. In order to calculate the ratio of traveling wave power to reflected wave power (VSWR), the reflected wave detection circuit 12 limits the band after DOWN-CONV and imports it into the A / D, and the reflected wave calculation unit 25 detects the reflected wave level. Is done.

  The reflected waves detected by the reflected wave detection circuits 12 to 14 in this way are taken into the reflected wave calculation unit 25, and the reflected wave calculation unit 25 detects the levels of these reflected waves and also detects the detected reflected wave levels. The location of the failure location is identified based on the result.

  The transmission high-frequency signal power input to the duplexer 8 is passed through a band-pass filter having a predetermined transmission high-frequency signal band, and is output as a transmission-limited high-frequency signal power of a band-limited specified output. The transmission high-frequency signal power output from the duplexer 8 is supplied to the antenna (ANT) 9 via the terminal at the specified output end, and is radiated from the antenna (ANT) 9 as the transmission-limited high-frequency signal power of the band-limited specified output. .

  FIG. 2 shows an example when a path failure occurs at point A between the directional coupler 5 and the circulator 6. The transmission high-frequency signal returns to the directional coupler 5 as a reflected wave B at the failure point A. A part of this reflected wave is taken out from the isolation port 52 of the directional coupler 5 and output to the reflected wave detection circuit 14. The reflected wave detection circuit 14 detects the reflected wave B and outputs it to the reflected wave calculation unit 25. The circulator 6 and the circulator 7 have a characteristic of attenuating about 25 dB with respect to the reflected wave. Therefore, by determining the level of these reflected waves, it is possible to know in which part of the downstream side of the directional coupler 5 the reflection has occurred, so that the reflected wave calculation unit 25 detects the level of the reflected wave and A failure can be detected.

  FIG. 3 shows an example when a path failure occurs at a point C between the circulator 6 and the circulator 7. The transmitted high-frequency signal returns to the circulator 6 as a reflected wave D at the failure point C. This reflected wave passes through the circulator 6 to the reflected wave detection circuit 13 side. The reflected wave detection circuit 13 detects this reflected wave and outputs it to the reflected wave calculation unit 25. The circulator 7 has a characteristic of attenuating about 25 dB with respect to the reflected wave. Therefore, by determining the level of the reflected wave, it is possible to know in which part of the circulator 6 downstream the reflection has occurred, so the reflected wave calculation unit 25 detects the level of the reflected wave and detects a failure at point C. be able to.

  As described above, according to the present embodiment, a failure can be easily detected when a connection failure or a failure occurs in a device or the like in the signal transmission path of the distortion compensation amplification device. In addition, in the present embodiment, a failure is detected using a circulator instead of a directional coupler, as compared with the conventional one in which a directional coupler is inserted on the output side of the isolator 103 shown in FIG. As a result, there is no transmission loss due to the directional coupler. Therefore, failure detection can be performed without increasing the transmission loss on the output side, and the efficiency of the distortion compensation amplifying device does not deteriorate.

(Second Embodiment)
FIG. 4 shows a circuit configuration of a distortion compensation amplifying apparatus 30 according to the second embodiment of the present invention. 4, the same reference numerals as those in the configuration diagram shown in FIG. 1 denote the same components.
The distortion compensation amplifying apparatus 30 of the present embodiment is different from the distortion compensation amplifying apparatus 1 of the first embodiment in the following points. That is, in the first embodiment, the reflected wave output is extracted from each of the isolation port 52 of the directional coupler 5, the third port of the circulator 6, and the third port of the circulator 7. The reflected wave detection circuit 14, the reflected wave detection circuit 13, and the reflected wave detection circuit 12 are connected. In this embodiment, the reflected wave output from each of the directional coupler 5, the circulator 6, and the circulator 7 is switched to the switch 35. Are output to the contacts a, b, and c, and are switched and selected by the switch 35 to be connected to one reflected wave detection circuit 36.

In this embodiment, since the reflected wave detection circuit 36 is common, for example, the reflected wave calculation unit 37 switches the contacts a, b, and c of the switch 35 in order, and the reflected wave detection circuit 36 is time-divisionally or intermittently. The reflected waves from the directional coupler 5, circulator 6, and circulator 7 are detected and output to the reflected wave calculation unit 37. The reflected wave calculation unit 37 detects the level of the reflected wave based on the signal from the reflected wave detection circuit 36, and specifies the position of the failure location based on the detected reflected wave level.
Other details are the same as those in the first embodiment, and a detailed description thereof will be omitted.

  According to the present embodiment, as in the first embodiment, when a connection failure or a failure such as a device occurs in the signal transmission path of the distortion compensation amplification device, the failure can be easily detected. In addition, in the present embodiment, a failure is detected using a circulator instead of a directional coupler, as compared with the conventional one in which a directional coupler is inserted on the output side of the isolator 103 shown in FIG. As a result, there is no transmission loss due to the directional coupler. Therefore, failure detection can be performed without increasing the transmission loss on the output side, and the efficiency of the distortion compensation amplifying device does not deteriorate. Furthermore, according to the present embodiment, since the reflected wave detection circuit is shared, there is an effect that the circuit configuration is simplified.

Summarizing the characteristics of the above embodiment, the distortion compensation amplification apparatus of the present embodiment is a distortion compensation amplification apparatus that amplifies a transmission high-frequency signal obtained by up-converting transmission data by an amplifier and outputs the amplified signal from an antenna. And a directional coupler, a first circulator, and a second circulator inserted in the transmission path of the antenna, and ports of the directional coupler, the first circulator, and the second circulator from which reflected waves are extracted. And a reflected wave detection circuit connected thereto.
Further, in the distortion compensation amplification apparatus according to the second embodiment, the reflected wave detection circuit is connected to a port from which the reflected wave of the directional coupler, the first circulator, and the second circulator is taken out via a switch. It is characterized by that.
The switch in the distortion compensation amplifier of the second embodiment sequentially takes out the reflected waves of the directional coupler, the first circulator, and the second circulator and outputs them to the reflected wave detection circuit. It is characterized by.
Further, in the distortion compensation amplifying apparatus of the present embodiment, the first circulator and the second circulator include at least a first port to which the transmission high-frequency signal is input, a second port to which the transmission high-frequency signal is output, and A third port from which a reflected wave from the second port side is output is provided, and the reflected wave detection circuit is connected to the third port of the first circulator and the second circulator.
In addition, the distortion compensation amplification apparatus according to the present embodiment is characterized in that the reflected wave detection circuit is connected to an isolation port of the directional coupler.
In addition, the distortion compensation amplification apparatus according to the present embodiment includes a failure detection unit that detects a failure location in the transmission path of the amplifier and the antenna based on the output level of the reflected wave detection circuit. .

  Although the present invention has been specifically described above by way of the embodiments, it is needless to say that these embodiments are exemplifications and can be modified and implemented without departing from the gist of the present invention. For example, an example in which the present invention is applied to a digital predistortion type amplifier has been described as an embodiment, but the present invention can also be applied to a feedforward amplifier as shown in FIG.

  The present invention is not limited to the distortion compensation amplifying apparatus used for the transmitter, but can be widely used for the failure detection technique of the high frequency amplifier.

It is a figure which shows the circuit structure of the distortion compensation amplification apparatus by the 1st Embodiment of this invention. It is a figure explaining the failure detection of the distortion compensation amplification apparatus by the 1st Embodiment of this invention. It is a figure explaining other examples of failure detection of a distortion compensation amplification device by a 1st embodiment of the present invention. It is a figure which shows the circuit structure of the distortion compensation amplification apparatus by the 2nd Embodiment of this invention. It is a figure which shows an example of the circuit structure of the distortion compensation amplification apparatus by a prior art.

Explanation of symbols

1, 30, 100: Distortion compensation amplifiers 2, 31, 101: Digital predistortion signal processing unit (DPD signal processing unit)
3. Amplitude / phase modulator (analog quadrature modulator)
4 ... Power amplifier (AMP)
5, 10, 102 ... Directional coupler (coupler)
6, 7 ... Circulator 8 ... Duplexer (DUP)
9 ... Antenna 11 ... Strain detection circuit (Strain DET)
12-14, 36 ... reflected wave detection circuit 15 ... transmission data 20 ... DPD calculation unit 21 ... multicarrier modulation wave IQ generation unit 22 ... distortion compensation calculation unit 23 ... distortion wave Monitor unit 24, 25, 37 ... reflected wave calculation unit 35 ... switch 51 ... coupling port 52 ... isolation port 103 ... isolator

Claims (1)

In a distortion compensation amplification device that amplifies a transmission high-frequency signal obtained by up-converting transmission data by an amplifier and outputs it from an antenna,
A directional coupler, a first circulator, and a second circulator inserted in the transmission path of the amplifier and the antenna;
A distortion compensation amplifying apparatus comprising: a reflected wave detection circuit connected to a port from which a reflected wave is taken out of the directional coupler, the first circulator, and the second circulator.

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