JP2007274374A - Multi-channel power amplifier and relay broadcasting apparatus using the power amplifier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To discriminate an abnormality in each input signal level or an output signal level by a Ch if an input signal has 2Chs or more, and further, to also discriminate an abnormality in a power amplifier itself. <P>SOLUTION: A MCPA is configured as follows. Branchers are provided at the input side and the output side of each of two or more internal power amplifiers, distributors are connected to the respective branchers, Ch extraction filters are connected to the respective distributors, and detectors are connected to the respective filters, so that an abnormality in the input signal can be detected by a Ch by the input side detector and an abnormality in an output signal amplified by each of the power amplifiers by the Ch and an abnormality in the internal power amplifiers can be detected by the output side detector. Such a MCPA is used for a relay broadcasting apparatus. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a multi-channel power amplifier (MCPA) of a single power amplification method and a parallel synthesis method and a relay broadcasting apparatus using the same, and is used in a relay station for television broadcasting, CATV broadcasting, a mobile base station in mobile radio communication, etc. It is what is used.

  Conventionally, as a power amplification method for relay broadcasting equipment, a method of obtaining specified power with a single channel power amplifier (SCPA) and an output of a multi channel power amplifier (MCPA) are combined. Thus, there are various methods such as a method of obtaining specified power (parallel synthesis method).

(Single power amplifier type SCPA and its level abnormality detection method)
An example of a relay broadcast device using SCPA is shown in FIG. FIG. 4 shows a case where the input signal is 1 wave (1 channel: 1 Ch). In this relay broadcasting device, the input signal received by the receiving antenna is frequency-converted to the required frequency band by an orthogonal frequency division multiplexing signal converter (signal processor: OFDM-SP: Orthogonal Frequency Division Multiplexing-Signal Processor) and input to SCPA. , Level amplified by SCPA's internal power amplifier (PA) and output.

  Abnormality detection of the input signal level and the output signal level in the relay broadcast apparatus of FIG. 4 is performed as follows. A part of the input signal is branched by the input branching device A of SCPA, the input level is detected by the input side detector (DET), and a part of the output signal is branched by the output side branching device B. (DET) is used to detect the output level. In this case, since the input signal is 1 Ch, if the input signal (radio wave) stops and stops or the level is lowered, the level detected by the input DET will be lost or lowered, and the level of the input signal will be abnormal. When the detection voltage level at the input DET is normal and the detection voltage level at the output DET is abnormal, it can be determined that the output signal level is abnormal and the SCPA PA is abnormal.

(Single power amplifier type MCPA and its level abnormality detection method)
An example of a relay broadcasting apparatus using a single power amplifier type MCPA is shown in FIG. FIG. 5 shows a case where the input signal is two waves (2Ch). In this relay broadcasting device, the input signal received by the receiving antenna is demultiplexed by Ch with 2 demultiplexer (2DIV), and each Ch input signal is separately required frequency band by two OFDM-SP connected in parallel. The output signals from both OFDM-SPs are mixed by a mixer (2MIX), input to one MCPA, level-amplified by the PA of the MCPA, and output.

In order to detect abnormalities in the input level and output level of the relay broadcasting device in FIG. 5, a part of the input signal is branched by the MCPA input side branching device A, the input level is detected by the input side DET, and the output side branching is performed. A part of the output signal is branched by the device B, and the level of the output signal is detected by the output side DET. In this case, it can be determined as follows based on the detection result.
1. When the detection voltage level of the input side DET is down (abnormal), an abnormality occurs from the input terminal (IN) to the 2nd demultiplexer (2DIV).
2. When there is no detection voltage level on the input side DET, both input radio waves are stopped.
3. PA is abnormal when the input DET detection voltage level is normal and the output DET detection voltage level is down (abnormal).

(Parallel composite power amplifier type MCPA and its level abnormality detection method)
FIG. 6 shows another example of the relay broadcasting apparatus using the parallel combined power amplifier type MCPA. FIG. 6 shows a case where the input signal is two waves (2Ch). In this relay broadcasting device, the input signal received by the receiving antenna is demultiplexed by Ch with 2 demultiplexer (2DIV), and each Ch input signal is separately required frequency band by two OFDM-SP connected in parallel. The output signals from both OFDM-SPs are mixed by the mixer (2MIX), demultiplexed into two channels by the second demultiplexer (2DIV), and each Ch signal is separated into two MCPAs. Are amplified and level amplified by MCPA PA, and their outputs are mixed by 2MIX and transmitted.

In order to detect an abnormality in the input level and output level of the relay broadcast apparatus in FIG. 6, a part of the input signal is branched by the input side branching devices A of the two transmission paths C and D of MCPA. The input level is detected by the input side DET, a part of the output signal is branched by the output side branching devices B of the transmission lines C and D, and the level of the output signal is detected by the output side DET. In this case, it can be determined as follows based on the detection result.
1. When the detection voltage level of the input side DET is down (abnormal), an abnormality occurs from the input terminal (IN) to the 2nd demultiplexer (2DIV).
2. When there is no detection voltage level on the input side DET, both input radio waves are stopped.
3. PA is abnormal when the input DET detection voltage level is normal and the output DET detection voltage level is down (abnormal).

  5 and 6, since the input signal is 2Ch, even if the detection voltage level of the input DET goes down and the level goes down due to the stoppage of the input signal, which Ch is stopped. Or it cannot be judged whether the level is down. In order to determine the cause, it is troublesome to compare the detection level of the input DET with the output level of each OFDM-SP.

  In the present invention, when the input signal is 2 Ch or more, the abnormality of each input signal level and output signal level can be discriminated for each Ch, and further, the abnormality of the power amplifier itself can be discriminated.

  The multi-channel power amplifier according to claim 1 of the present application is an MCPA of a single power amplification method, and a relay broadcasting apparatus that amplifies an input signal of 2 Ch or more with one internal power amplifier in one MCPA and outputs it to the outside In the present invention, a branching device is provided on the input side and output side of the internal power amplifier, a distributor is connected to each branching device, and a filter for extracting the Ch is connected to each distributor, and each filter is detected. A detector is connected and the input side detector can detect abnormalities in the input signal for each Ch, and the output side detector detects abnormalities per channel in the output signal amplified by the internal power amplifier and abnormalities in the internal power amplifier. It is something that can be done.

  The multi-channel power amplifier according to claim 2 of the present application is a parallel composite power amplification type MCPA, and two or more MCPAs in which two or more internal power amplifiers are connected in parallel are connected in parallel, and each MCPA has an individual internal power. In a relay broadcasting device that amplifies input signals of 2 Ch or more with an amplifier, synthesizes the amplified signals in each MCPA, synthesizes synthesized signals output from two or more MCPAs, and outputs them to the outside. Each of the two or more internal power amplifiers is provided with a branching device on each input side and output side, a distributor is connected to each branching device, and a filter for extracting the Ch is connected to each distributor. The detector is connected to the input side, the input side detector can detect the abnormality of the input signal for each Ch, the output side detector amplifies the output signal amplified by each of the power amplifiers, and the internal power amplifier. Can detect abnormalities Those were Unishi.

  The MCPA according to claim 3 of the present application is also a parallel composite power amplification type MCPA, and two or more MCPAs in which two or more internal power amplifiers are connected in parallel are connected in parallel, and each internal power amplifier of each MCPA is 2 Ch or more. In the relay broadcasting device that amplifies the input signals of the two, synthesizes the amplified signals in each MCPA, synthesizes the synthesized signals output from two or more MCPAs, and outputs them to the outside, each MCPA has two or more internal The input side of the power amplifier is a common transmission line, and the common transmission line is provided with a common branching unit. The common branching unit is connected to a branching end of the branching unit, and is input to each of two or more distributioning ends of the splitter. A filter for extracting a signal for each channel is connected, two or more transmission paths are provided on the output side of the branching unit, an internal power amplifier is connected to each transmission path, and a branching unit is connected to the output side of the internal power amplifier. The branch end of each branching device is provided Distributors are connected, and filters for extracting input signals for each Ch are connected to each distribution end, and detectors are connected to each filter, so that abnormalities in the input signals can be detected for each Ch by the detector of the common branch section. The detector on the output side can detect the Ch-specific abnormality of the output signal amplified by each of the power amplifiers and the abnormality of the internal power amplifier.

  A relay broadcast apparatus according to claim 4 of the present application is a relay broadcast apparatus that amplifies an input signal of 2 Ch or more with one internal power amplifier in one MCPA and outputs the amplified signal to the outside. A channel power amplifier is used.

  In the relay broadcast apparatus according to claim 5 of the present application, two or more MCPAs in which two or more internal power amplifiers are connected in parallel are connected in parallel, and each MCPA individual internal power amplifier amplifies an input signal of 2 Ch or more. 4. The multi-channel power according to claim 2, wherein the amplified signals are combined in each MCPA, and the combined signals output from two or more MCPAs are combined and output to the outside. An amplifier is used.

  The multi-channel power amplifier according to claim 1 can detect abnormalities of input signal level / output signal level of 2Ch or more for each Ch, and can determine whether the input signal level is abnormal or the power amplifier is abnormal. Therefore, maintenance and management are easy.

  The multi-channel power amplifiers according to claims 2 and 3 can also detect abnormalities in the input signal level and output signal level of 2 Ch or more separately for each Ch, and can reliably detect and discriminate the abnormality of MCPA itself and the abnormality occurrence location. So maintenance and management become easy. In addition, the signal power can be increased because the MCPA is a parallel synthesis method.

  Since the multi-channel power amplifier according to the third aspect is provided with the common branch portion, in addition to the above effects, there is an effect that the configuration is simple and inexpensive.

  Since the multi-channel power amplifier according to claim 1 is used in the relay broadcast device according to claim 4, a relay broadcast device having the same effect as the multi-channel power amplifier according to claim 1 is obtained.

  Since the relay broadcast apparatus according to the fifth aspect uses the multi-channel power amplifier according to the second and third aspects, the relay broadcast apparatus has the same effect as the multi-channel power amplifier according to the second and third aspects.

(Embodiment 1)
A first example of a relayed broadcasting apparatus using the MCPA of the present invention is shown in FIG. Similar to the relay broadcast apparatus shown in FIG. 4, this relay broadcast apparatus uses a single MCPA of a single power amplifier system incorporating only one internal power amplifier.

  In the relay broadcasting apparatus of FIG. 1, the input signal received by the receiving antenna is frequency-converted to a required frequency band by OFDM-SP, the output signal from OFDM-SP is input to MCPA, and the level is amplified by the PA in MCPA. Is output.

  The MCPA in FIG. 1 is provided with an input branching device 1 and an output branching device 2 between an input terminal (IN) and an output terminal (OUT), and a PA is disposed between both branching devices 1 and 2. A distributor 3 is connected to a branch end of the input side branching device 1, a band pass filter (BPF) is connected to each of the two distribution ends of the distributor 3, and a DET is connected to each BPF. A distributor 4 is connected to the branch end of the output-side branching device 2, BPFs are connected to the two distributing ends of the distributor 4, and DETs are connected to the respective BPFs.

(Abnormality detection with the amplifier in Fig. 1)
In the MCPA of FIG. 1, BPF is connected to each of the two distribution ends of the distributor 3 on the input side and to each of the two distribution ends of the distributor 4 on the output side. If two BPFs are used for Ch1 and Ch2 and Ch1 and Ch2, the input DET detects abnormalities in the Ch1 and Ch2 input signals, and the output DET detects abnormalities in the Ch1 and Ch2 output signals. be able to. Further, if the input signal levels of Ch1 and Ch2 detected by the input side DET are normal, but the output signal levels of Ch1 and Ch2 detected by the output side DET are abnormal, it is determined that the PA is abnormal. be able to.

(Embodiment 2)
FIG. 2 shows a second example of the relay broadcast apparatus using the MCPA of the present invention. This relay broadcast apparatus uses two MCPAs with built-in power amplifiers.

  In the relay broadcasting device of FIG. 2, the input signal received by the receiving antenna is demultiplexed by the 2 demultiplexer (2DIV), and each Ch input signal is separately required by two OFDM-SPs connected in parallel. The output signals from both OFDM-SPs are mixed by a mixer (2MIX), input to the next MCPA, level amplified by each PA of the MCPA, and output.

  The two MCPAs in FIG. 2 have the same configuration and the same functions, and include an input-side hybrid coupler (HYB) and an output-side hybrid coupler (HYB), and two transmission paths 5 and 6 between them. Each of the transmission lines 5 and 6 is provided with an input-side branching device 1 and an output-side branching device 2, an internal amplifier (PA1, PA2) is provided between both branching devices 1 and 2, A distributor 3 is connected to one end, a BPF is connected to two distribution ends of the distributor 3, and a DET is connected to each BPF. A distributor 4 is connected to the branch end of the output-side branching device 2, BPFs are connected to the two distributing ends of the distributor 4, and DETs are connected to the respective BPFs.

(Abnormality detection in the amplifier of FIG. 2)
The MCPA in FIG. 2 has BPFs connected to the input and output sides of the two transmission lines 5 and 6, so if two BPFs on the input and output sides are used for Ch1 and Ch2, respectively. It is possible to detect an abnormality in the input signals of Ch1 and Ch2 on the input side DET of the transmission lines 5 and 6, and an abnormality in the output signals of Ch1 and Ch2 on the output side DET. If the input signal levels of Ch1 and Ch2 detected at the input side DET of each transmission line are normal, but the output signal levels of Ch1 and Ch2 detected at the output side DET are abnormal, MCPA It can be determined that the PA is abnormal.

(Embodiment 3)
FIG. 3 shows a third example of the relay broadcast apparatus using the MCPA of the present invention. This relay device also uses two MCPAs with built-in power amplifiers. The MCPA in FIG. 3 is the input branching device 1 of both transmission paths 3 and 4 of the MCPA shown in FIG. 2 and the input connected thereto. The side distributor 3 and the two BPFs connected to the two distribution ends of the branching unit 3 and the two DETs connected to the respective BPFs are combined into one block and arranged as a common branching unit 7 in the preceding stage of the input side HYB. However, the PA, the output branching device 2, the distributor 4, the two BPFs, and the two DETs provided in the transmission lines 5 and 6 between the input side HYB and the output side HYB are left. Two BPFs connected to the two distribution ends of the distributor 4 are for Ch1 and Ch2, respectively.

  In the relay broadcasting apparatus of FIG. 3, the 2ch input signal received by the receiving antenna is demultiplexed by the 2 demultiplexer (2DIV), and separately required by two OFDM-SPs in which each Ch input signal is connected in parallel. The frequency is converted to the frequency band, the output signals from both OFDM-SPs are mixed by the mixer (2MIX), demultiplexed into two Ch signals by the next two demultiplexers (2DIV), and each Ch signal is separated separately. Input to each of the two MCPAs. The signal input to the MCPA is output via the input side branching device 1-input side HYB-transmission path 5, 6-PA-output side branching device 2, output side HYB. The signals output from the two MCPAs are mixed by 2MIX and transmitted from the transmitting antenna to the outside.

(Abnormality detection in the amplifier of FIG. 3)
1. In the MCPA of FIG. 3, the input signal of 2Ch is branched by the input side branching device 1, divided by 2 by the input side distributor 3, extracted by Ch by BPF, and the level is detected by each DET. Level abnormalities can be identified for each channel.
2. The signals amplified by the PAs of the transmission lines 5 and 6 in FIG. 3 are branched by the output-side branching device 2 in the subsequent stage, divided into two by the output-side divider, and extracted by Ch by the BPF. Since the level is detected at, an abnormal level of the output signal can be determined for each Ch. In this case, when there is no abnormality in the input signal level and there is an abnormality in the output signal level, it can be determined that the PA is abnormal. In this case, it is also possible to determine which transmission system PA is abnormal.

  In any of the first to third embodiments, the receiving antenna, the duplexer (2DIV), the two OFDM-SPs arranged in parallel, the mixer (2MIX), the HYB, and the transmitting antenna are the same as those shown in FIGS. They may be of the same configuration and function, or may be improved.

The block diagram which shows an example of the relay broadcasting apparatus using MCPA of the single power amplifier system of this invention. The block diagram which shows an example of the relay broadcasting apparatus using MCPA of the parallel composition system of this invention. The block diagram which shows the other example of the relay broadcasting apparatus using MCPA of the parallel composition system of this invention. The block diagram which shows an example of the relay broadcasting apparatus using SCPA of the conventional single power amplifier system. The block diagram which shows an example of the relay broadcasting apparatus which used MCPA of the conventional single power amplifier system. The block diagram which shows the other examples of the relay broadcast apparatus using MCPA of the conventional parallel composition system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Input side branch device 2 Output side branch device 3 Input side distributor 4 Output side distributor 5, 6 Transmission line 7 Common branch part
MCPA multi-channel power amplifier
BPF bandpass filter
DET detector
HYB input and output hybrid couplers
PA Internal power amplifier 2DIV Divider
OFDM-SP Orthogonal Frequency Division Multiplex Signal Converter 2MIX Mixer

Claims (5)

  In the MCPA of the relay broadcasting apparatus that amplifies an input signal of 2 channels (Ch) or more with one internal power amplifier in the multi-channel power amplifier (MCPA) and outputs it to the outside, the input side and the output side of the internal power amplifier A branching device is provided, a distributor is connected to each branching device, a filter for extracting the Ch is connected to each distributor, a detector is connected to each filter, and a detector on the input side The multi-channel power is characterized in that the abnormality of the input signal can be detected for each Ch, and the output side detector can detect the abnormality for each Ch of the output signal amplified by the internal power amplifier and the abnormality of the internal power amplifier. amplifier.   Two or more MCPAs connected in parallel with two or more internal power amplifiers are connected in parallel, and each MCPA's individual internal power amplifier amplifies the input signal of 2Ch or more, and synthesizes the amplified signals in each MCPA. In the MCPA of the relay broadcasting apparatus that synthesizes the synthesized signals output from two or more MCPAs and outputs them to the outside, each MCPA is provided with branching devices on the input side and the output side of two or more internal power amplifiers. A distributor is connected to each branching device, a filter for extracting the Ch is connected to each distributor, a detector is connected to each filter, and the input side detector detects an abnormality in the input signal Ch. A multi-channel power amplifier, which can be detected separately, and an abnormality of each output signal and an abnormality of an internal power amplifier of an output signal amplified by each of the power amplifiers can be detected by a detector on the output side.   Two or more MCPAs connected in parallel with two or more internal power amplifiers are connected in parallel, and each MCPA's individual internal power amplifier amplifies the input signal of 2Ch or more, and synthesizes the amplified signals in each MCPA. In the MCPA of the relay broadcasting apparatus that synthesizes the composite signals output from two or more MCPAs and outputs them to the outside, each MCPA uses the input side of two or more internal power amplifiers as a common transmission line, and the common transmission line A common branching unit is provided. A divider is connected to the branching end of the branching unit, and a filter for extracting an input signal for each Ch is connected to each of two or more distributioning ends of the splittering unit. 2 or more transmission lines are provided, internal power amplifiers are connected to the respective transmission lines, a branching device is provided on the output side of these internal power amplifiers, and a distributor is connected to the branching end of each branching device. Input signal to each distribution terminal by Ch Filters are connected to each other, detectors are connected to the respective filters, and the abnormality of the input signal can be detected for each Ch by the detector of the common branch section, and amplified by each of the power amplifiers by the detector on the output side. A multi-channel power amplifier characterized by being able to detect Ch-specific abnormalities of output signals and internal power amplifier abnormalities.   In a relay broadcasting apparatus that amplifies an input signal of 2 Ch or more with one internal power amplifier in one MCPA and outputs it to the outside, the multi-channel power amplifier according to claim 1 is used for the MCPA. Broadcast equipment. Two or more MCPAs connected in parallel with two or more internal power amplifiers are connected in parallel, and each MCPA's individual internal power amplifier amplifies the input signal of 2Ch or more, and synthesizes the amplified signals in each MCPA. A relay broadcast apparatus for combining a composite signal output from two or more MCPAs and outputting the composite signal to the outside, wherein the multi-channel power amplifier according to claim 2 or 3 is used for the MCPA. .

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