JP2020057957A - Amplifying device, down converter, and receiving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust a peak level of an output signal to a certain value or less even if the dynamic range of an input signal is large. SOLUTION: A first attenuator that attenuates an input signal with a first attenuation amount corresponding to a first control signal and outputs a first attenuated signal, and an amplifier that amplifies the first attenuated signal and outputs an amplified signal. A second attenuator that attenuates the amplified signal output from the amplifier and outputs a second attenuated signal with a predetermined second attenuation amount, a strength of the second attenuated signal, and a predetermined reference strength of the signal. Provided is an amplification device including a first signal generation unit for generating a first control signal based on the result of comparison. [Selection diagram] Fig. 2

Description

  The present invention relates to an amplification device, a down converter, and a reception device.

  2. Description of the Related Art There is known an automatic gain control (AGC) automatic gain control (AGC) amplifier that automatically controls the gain of the amplifier (see, for example, Patent Documents 1 and 2).

JP 2001-61133 A JP-A-2002-94408

  Such an amplifier stabilizes the peak value of the output signal within an appropriate intensity range by, for example, feeding back the peak value of the output signal and adjusting the gain, even if the signal intensity of the input signal fluctuates. However, when such an amplifying device is used for satellite communication or the like, an input signal of the amplifying device becomes a weak signal such as noise when a signal from a satellite is being searched. That is, when comparing the state after the satellite is captured with the state before the satellite is captured, a signal whose signal strength differs by several digits or more may be input to the amplifier. In this case, if the amplification device is controlled to increase the gain in response to the weak signal, a sudden increase in the input signal after the acquisition of the satellite causes a large signal such that a circuit at the subsequent stage of the amplification device is destroyed. May occur.

  Therefore, the present invention has been made in view of these points, and an object of the present invention is to provide an amplifier capable of adjusting the peak level of an output signal to a certain value or less even when the dynamic range of an input signal is large.

  In a first aspect of the present invention, a first attenuator for attenuating an input signal by a first attenuation amount according to a first control signal and outputting a first attenuated signal, and amplifying and amplifying the first attenuated signal An amplifier that outputs a signal, a second attenuator that attenuates the amplified signal output from the amplifier by a predetermined second attenuation and outputs a second attenuated signal, and an intensity of the second attenuated signal; An amplification device comprising: a first signal generation unit configured to generate the first control signal based on a result of comparing a predetermined signal with a reference intensity.

  The first signal generation unit generates the first control signal for increasing the first attenuation when the intensity of the second attenuation signal is greater than the reference intensity, and generates the first control signal for increasing the first attenuation. When the intensity is smaller than the reference intensity, the first control signal for reducing the first attenuation may be generated.

  A second signal generation unit that generates a second control signal that controls an amount of attenuation of the second attenuator, wherein the second attenuator converts the amplified signal with the second amount of attenuation according to the second control signal. May be attenuated. The amplifying device may further include a detection unit that detects the intensity of the second attenuated signal based on a part of the power extracted from the second attenuated signal. The amplifying device may further include a storage unit that stores a value indicating the second attenuation amount determined in a state where the first attenuation amount is minimum.

  In a second aspect of the present invention, a signal generator for generating a predetermined frequency signal, and a mixer for mixing the predetermined frequency signal and an input high-frequency signal to generate a mixing signal And a down-converter comprising: the amplifier according to the first aspect, which receives the mixing signal as the input signal.

  According to a third aspect of the present invention, there is provided a receiving apparatus comprising: an antenna that receives a radio signal from a satellite and converts it into an electric signal; and a down converter according to a second aspect that receives the electric signal as the high-frequency signal. provide.

  According to the present invention, there is an effect that the peak level of the output signal of the amplifier can be adjusted to a certain value or less even if the dynamic range of the input signal is large.

1 shows a configuration example of a ground station 100 according to the present embodiment together with a satellite 10. 2 shows a configuration example of a down converter 130 according to the present embodiment. 4 shows an example of input / output characteristics of the amplification device 200 according to the present embodiment. 4 shows an example of a gain characteristic of the amplifying device 200 according to the present embodiment.

<Configuration example of satellite system>
FIG. 1 shows a configuration example of a ground station 100 according to the present embodiment together with a satellite 10. The ground station 100 communicates with space satellites, spacecraft, and the like. FIG. 1 shows an example of a ground station 100 communicating with a satellite 10. The satellite 10 and the ground station 100 communicate using a radio signal whose carrier is modulated according to a signal to be transmitted. The ground station 100 includes an antenna 110, an input / output circuit 120, a down converter 130, a signal processing unit 140, and an up converter 150.

  The antenna 110 receives a radio signal transmitted from the satellite 10 and converts it into an electric signal. The antenna 110 converts an electric signal into a radio signal and transmits the radio signal to the satellite 10. The antenna 110 is, for example, an antenna that also performs transmission and reception. Alternatively, antenna 110 may have separate transmitting and receiving antennas.

  The input / output circuit 120 supplies an electric signal from the antenna 110 to the down converter 130. Further, the input / output circuit 120 supplies an electric signal from the up-converter 150 to the antenna 110. The input / output circuit 120 includes a circulator 121, an input filter 122, an input amplifier 123, an output amplifier 124, and an output filter 125.

  The circulator 121 has a plurality of input / output ports. The circulator 121 outputs a signal input to one port from the next port, outputs a signal input from the next port from the next port, and outputs a signal input to the last port from the one port. Let it. FIG. 1 shows an example in which the circulator 121 has three input / output ports. In this case, circulator 121 outputs an electric signal received from antenna 110 to input filter 122. Further, circulator 121 outputs an electric signal received from output filter 125 to antenna 110.

  The input filter 122 passes a signal in a frequency band including the signal frequency of the electric signal received from the circulator 121 to the input amplifier 123. Further, the input filter 122 reduces signals in a frequency band different from the frequency band. The input filter 122 includes, for example, at least one of a band-pass filter, a low-pass filter, and a high-pass filter.

  The input amplifier 123 amplifies and outputs a signal received from the input filter 122. The input amplifier 123 amplifies the signal at a predetermined amplification factor. The input amplifier 123 supplies the amplified signal to the down converter 130. Output amplifier 124 amplifies and outputs a signal received from up-converter 150. The output amplifier 124 amplifies the signal at a predetermined amplification factor. The output amplifier 124 supplies the amplified signal to the output filter 125.

  The output filter 125 passes a signal in a frequency band including the signal frequency of the electric signal received from the output amplifier 124 to the antenna 110. Further, the output filter 125 reduces a signal in a frequency band different from the frequency band. The output filter 125 includes, for example, at least one of a band-pass filter, a low-pass filter, and a high-pass filter.

  Down converter 130 receives the electric signal converted by antenna 110 as a high-frequency signal via input / output circuit 120. The down converter 130 extracts the modulated signal superimposed on the high-frequency signal and supplies it to the signal processing unit 140.

  The signal processing unit 140 converts the modulated signal received from the down converter 130 into a digital signal and performs digital processing. The signal processing unit 140 demodulates the modulated signal and restores the modulated signal to a signal transmitted by the satellite 10. The signal processing unit 140 may further digitally process the restored signal according to the purpose of communication with the satellite 10. Further, the signal processing unit 140 generates a modulated signal according to a signal to be transmitted to the satellite 10. The signal processing unit 140 converts the modulated signal into an analog signal and supplies the analog signal to the up-converter 150.

  The up-converter 150 modulates the carrier with the modulation signal received from the signal processing unit 140. The up-converter 150 has, for example, a carrier generator and a mixer, and mixes a carrier and a modulated signal. The up-converter 150 supplies an electric signal obtained by modulating a carrier by mixing to the antenna 110 via the input / output circuit 120. The up-converter 150 may have a configuration of a known up-converter in wireless communication, and a detailed description thereof will be omitted.

  In the ground station 100 according to the above embodiment, the antenna 110, the input / output circuit 120, the down converter 130, and the signal processing unit 140 function as a receiving device, and the antenna 110, the input / output circuit 120, the signal processing unit 140, The up-converter 150 functions as a transmission device. Note that the ground station 100 may have only the function of the receiving device. The configurations of the input / output circuit 120, the signal processing unit 140, and the like are merely examples, and may be appropriately configured according to the purpose of communication.

  Such a ground station 100 searches for a radio signal from the satellite 10 and receives the radio signal to capture the satellite 10 and make it communicable. Therefore, while searching for a wireless signal, the signal received by the downconverter 130 provided in the ground station 100 is a weak signal such as noise. In a state in which the satellite 10 can be captured and communicated, the signal received by the downconverter 130 is a signal that is several orders of magnitude larger than noise. As described above, since the input signal of the down converter 130 has a large dynamic range, it is difficult to automatically adjust the gain of the amplifying device inside the down converter 130.

  For example, if the amplification device is controlled to increase the gain in response to a weak signal, a sudden increase in the input signal after capturing the satellite causes a signal large enough to destroy a circuit at the subsequent stage of the amplification device. May cause it. Further, if the gain is limited according to the input signal after the satellite is captured, a weak signal for searching for the satellite 10 may not be sufficiently amplified, and it may be difficult to capture the satellite 10. Therefore, the downconverter 130 according to the present embodiment is provided with an amplifying device that can adjust the peak level of the output signal to a certain value or less even if the dynamic range of the input signal is large, and appropriately modulates the input signal. Convert to a signal. The down converter 130 will be described below.

<Configuration Example of Down Converter 130>
FIG. 2 shows a configuration example of the down converter 130 according to the present embodiment. The down converter 130 extracts a modulation signal from the high-frequency signal by mixing and filtering, and amplifies the extracted modulation signal. The down converter 130 includes a first isolator 131, a first amplifier 132, a signal generator 133, a mixer 134, a filter 135, a second amplifier 136, and an amplifier 200.

  The first isolator 131 supplies the high-frequency signal received from the input / output circuit 120 to the first amplifier 132 at the subsequent stage. In addition, the first isolator 131 prevents transmission of a signal from the first amplifier 132 to the input / output circuit 120. The first isolator 131 reduces a signal traveling in the reverse direction, prevents a decrease in communication quality due to noise or the like, and protects circuit elements and the like. The first amplifier 132 amplifies and outputs a high-frequency signal received from the first isolator 131. The first amplifier 132 amplifies the high-frequency signal at a predetermined amplification factor. The first amplifier 132 supplies the amplified high-frequency signal to the mixer unit 134.

  The signal generator 133 generates a predetermined frequency signal. The signal generator 133 generates a frequency signal close to the frequency of the high-frequency signal. The signal generator 133 generates a frequency signal having a frequency obtained by subtracting or adding the frequency of the IF signal from the frequency of the carrier wave, for example, when the frequency signal supplied to the signal processing unit 140 at the subsequent stage of the down converter 130 is an IF signal. Let it. The signal generator 133 supplies the generated frequency signal to the mixer 134.

  Mixer section 134 generates a mixing signal by mixing a predetermined frequency signal and an input high-frequency signal. The mixer section 134 generates a mixing signal having a sum and difference frequency between the high-frequency signal received from the first amplifier 132 and the frequency signal received from the signal generator 133. The mixer unit 134 supplies the generated mixing signal to the filter unit 135.

  The filter unit 135 passes a part of the mixing signal. The filter unit 135 passes, for example, a difference signal between the high-frequency signal and the frequency signal to the second amplifier 136. In this case, the filter unit 135 reduces the sum signal of the high frequency signal and the frequency signal. It is desirable that the filter unit 135 reduces spurious components and noise components generated at a frequency different from the frequency of the difference signal. The filter unit 135 includes, for example, at least one of a band-pass filter, a low-pass filter, and a high-pass filter.

  The second amplifier 136 amplifies and outputs the mixing signal received from the filter unit 135. The second amplifier 136 amplifies the mixing signal at a predetermined amplification factor. The second amplifier 136 supplies the amplified mixing signal to the amplifier 200.

<Configuration Example of Amplifying Device 200>
The amplification device 200 receives the mixing signal from the first amplifier 132 as an input signal. The amplifying device 200 protects elements connected to the subsequent stage by providing elements for separately adjusting the gain when amplifying a weak signal and the gain when amplifying a signal larger than the reference intensity. While amplifying the input signal. The amplification device 200 includes a first attenuator 210, an amplifier 220, a second attenuator 230, a branching unit 240, a detection unit 250, a first signal generation unit 260, a storage unit 270, and a second signal generation unit 280. And a second isolator 290.

  The first attenuator 210 receives an input signal from the first amplifier 132, attenuates the input signal, and outputs a first attenuated signal. The first attenuator 210 is a variable attenuation attenuator. The first attenuator 210 receives the first control signal from the first signal generator 260, and attenuates the input signal by a first attenuation amount according to the first control signal. The first attenuator 210 supplies the first attenuated signal to the amplifier 220. That is, the first attenuator 210 adjusts the signal strength of the signal input to the amplifier 220.

  The amplifier 220 amplifies the first attenuated signal and outputs an amplified signal. The amplifier 220 amplifies the first attenuated signal at a predetermined amplification factor. The amplifier 220 supplies an amplified signal obtained by amplifying the first attenuated signal to the second attenuator 230.

  The second attenuator 230 attenuates the amplified signal output from the amplifier 220 by a predetermined second attenuation, and outputs a second attenuated signal. The second attenuator 230 is, for example, a variable attenuation attenuator. The second attenuator receives the second control signal from the second signal generation unit 280, and attenuates the amplified signal by a second attenuation according to the second control signal. The second attenuator 230 supplies the second attenuation signal to the branch unit 240. That is, the second attenuator 230 adjusts the signal strength of the signal output from the amplifier 220.

  The branching unit 240 supplies a part of the second attenuation signal received from the second attenuator 230 to the detection unit 250, and supplies the rest to the second isolator 290. The branching unit 240 branches the second attenuated signal at a predetermined branching ratio. The branching unit 240 makes the signal strength supplied to the detection unit 250 smaller than the signal strength supplied to the second isolator 290. For example, the branching unit 240 branches the second attenuated signal into about 10: 1. The branching unit 240 is, for example, a coupler such as a directional coupler.

The detecting section 250 receives a part of the second attenuated signal branched from the branching section 240 and measures the power of a part of the second attenuated signal. The detection unit 250 detects the intensity of the second attenuated signal based on a part of the power branched from the second attenuated signal. The detection unit 250 includes, for example, a power sensor and outputs a voltage value V _det corresponding to the measured power. Since the measurement result of the power is proportional to the intensity of the second attenuated signal, the detection unit 250 may output the voltage value V _det which is the measurement result of the power as it is as the detection result of the intensity of the second attenuated signal. The detection unit 250 supplies the detection result to the first signal generation unit 260.

The first signal generator 260 generates a first control signal based on a result of comparing the intensity of the second attenuated signal with a predetermined reference intensity of the signal. Here, the first signal generation unit 260 uses, for example, the voltage value V _det received from the detection unit 250 as the intensity of the second attenuation signal. In this case, the first signal generation unit 260 uses a predetermined reference voltage V _ref corresponding to the predetermined reference intensity as the reference intensity of the predetermined signal. The first signal generator 260 includes a reference voltage source 262 that outputs such a reference voltage _Vref .

The first signal generation unit 260 generates a first control signal for increasing the first attenuation when the intensity of the second attenuation signal is higher than the reference intensity. For example, when the voltage value V _det is larger than the reference voltage V _ref (V _det > V _ref ), the first signal generation unit 260 generates the first control signal so that the input signal is further attenuated by the first attenuator 210. I do. The first signal generator 260 supplies the first control signal to the first attenuator 210 to increase the first attenuation of the first attenuator 210. That is, the first signal generator 260 reduces the gain of the amplifier 200.

Further, the first signal generation section 260 generates a first control signal for reducing the first attenuation amount when the intensity of the second attenuation signal is smaller than the reference intensity. For example, when the voltage value V _det is smaller than the reference voltage V _ref (V _det <V _ref ), the first signal generation unit 260 generates the first control signal in a direction in which the first attenuator 210 does not attenuate the input signal. . The first signal generator 260 supplies the first control signal to the first attenuator 210 to reduce the first attenuation of the first attenuator 210. That is, the first signal generator 260 increases the gain of the amplifier 200.

The first signal generation unit 260 has, for example, a comparator such as a comparator, and supplies a comparison result of the voltage value V _det and the reference voltage V _ref to the first attenuator 210 as a first control signal. Further, at least a part of the first signal generation unit 260 may be configured by a computer or the like. In this case, the computer includes, for example, a processor such as a CPU, and functions as at least a part of the first signal generation unit 260 according to the present embodiment by executing a program or the like. The computer may further include a GPU (Graphics Processing Unit) or the like.

  As described above, the amplification device 200 substantially controls the amplification signal of the amplifier 220 by loop control by the first attenuator 210, the amplifier 220, the second attenuator 230, the branching unit 240, the detection unit 250, and the first signal generation unit 260. It can be a constant reference intensity. In the present embodiment, the range of the input signal from which the amplification device 200 can output the amplified signal as a substantially constant reference intensity is defined as a limiter region.

  Here, the amplification device 200 sets the amplified signal to a substantially constant reference intensity within the variable range of the first attenuation amount of the first attenuator 210. Therefore, when the intensity of the input signal is reduced below the range of the limiter region, the first attenuation remains at the minimum, and the amplifier 200 outputs an amplified signal having a magnitude smaller than the reference intensity. In this case, since the gain is fixed, the amplifier 200 outputs an amplified signal having an intensity proportional to the input signal. In the present embodiment, the range of an input signal from which the amplification device 200 outputs an amplified signal having an intensity proportional to the input signal is defined as a fixed gain region.

  When the range of the input signal is in the fixed gain region, the first attenuation of the first attenuator 210 is minimized, so that the gain of the amplifier 200 is determined by the second attenuation of the second attenuator 230. That is, by determining the second attenuation amount in advance, the gain of the amplifier 200 in the fixed gain region can be determined.

The storage unit 270 stores the value indicating the second attenuation determined in the state where the first attenuation is minimum as described above. The storage unit 270 includes a storage device such as a ROM (Read Only Memory) and a RAM (Random Access Memory). Further, storage unit 270 may store information on reference voltage V _ref . In this case, the reference voltage source 262 reads information stored in the storage unit 270, and outputs a reference voltage V _ref corresponding to the read information. The reference voltage source 262 has, for example, a DA converter or the like, and outputs a reference voltage V _ref based on information stored in the storage unit 270.

  When at least a part of the first signal generation unit 260 is configured by a computer or the like, the storage unit 270 is, for example, a ROM that stores a BIOS (Basic Input Output System) or the like of the computer and a work area. Includes RAM. Further, the storage unit 270 may store various information including an OS (Operating System), an application program, and / or a database referred to when the application program is executed. That is, the storage unit 270 may include a large-capacity storage device such as a hard disk drive (HDD) and / or a solid state drive (SSD).

  The second signal generator 280 generates a second control signal for controlling the amount of attenuation of the second attenuator 230. The second signal generation unit 280 reads the information stored in the storage unit 270 and supplies a second control signal corresponding to the read information to the second attenuator 230. The second signal generation unit 280 has, for example, a DA converter and the like, and supplies a second control signal based on the information stored in the storage unit 270 to the second attenuator 230. Note that, as with the first signal generation unit 260, at least a part of the second signal generation unit 280 may be configured by a computer or the like.

  The second isolator 290 outputs the second attenuated signal received from the branching unit 240 as an output signal of the amplifier 200. In addition, second isolator 290 prevents transmission of a signal from a subsequent stage of amplifying device 200 to branching unit 240. Similarly to the first isolator 131, the second isolator 290 reduces a signal traveling in the reverse direction, prevents a decrease in communication quality due to noise or the like, and protects circuit elements and the like.

  The amplifying device 200 according to the above-described embodiment switches to one of the operation in the fixed gain region and the operation in the limit region according to the signal strength of the input signal. The change in the output signal strength of the amplification device 200 according to such an input signal will be described below.

<Input / output characteristics of the amplification device 200>
FIG. 3 shows an example of input / output characteristics of the amplifying device 200 according to the present embodiment. The horizontal axis in FIG. 3 indicates the intensity of the input signal of the amplifier 200, and the vertical axis indicates the intensity of the output signal of the amplifier 200. Note that the intensity of the output signal of the amplifying device 200 is a part of the intensity of the second attenuated signal, but for the sake of convenience, the description will be made assuming that they substantially match. Further, an input signal when the output signal of the amplifier 200 has the reference intensity is defined as a first intensity.

When the input signal has a relatively small intensity equal to or less than the first intensity, the amplification device 200 outputs a signal having an intensity proportional to the input signal. Further, when the input signal becomes larger than the first intensity, the amplification device 200 outputs a signal having an intensity substantially equal to the reference intensity. Note that the magnitude of the reference intensity can be determined by the magnitude of the reference voltage _Vref . Here, it is desirable that the variable range of the reference intensity and the amount of attenuation of the first attenuator 210 be set so that even if the input signal is maximized, it is within the range of the limit area.

<Gain Characteristics of Amplifier 200>
FIG. 4 shows an example of a gain characteristic of the amplifying device 200 according to the present embodiment. The horizontal axis of FIG. 4 indicates the intensity of the input signal of the amplifier 200, and the vertical axis indicates the gain of the amplifier 200. When the input signal has a relatively small intensity equal to or less than the first intensity, the amount of attenuation of the first attenuator 210 becomes the minimum value, and the gain of the amplifier 200 becomes a substantially constant value. In this case, the gain of the amplifier 200 can be determined by the second attenuation of the second attenuator 230, that is, by the second control signal. Further, when the input signal becomes larger than the first strength, the gain of the amplification device 200 decreases in proportion to the strength of the input signal so that the strength of the output signal is used as the reference strength.

  When the input signal is a weak signal such as noise, the amplifying device 200 according to the present embodiment operates with a fixed gain without limiting the gain. Then, when the input signal is a signal large enough to exceed the first strength, the amplifying device 200 functions as a limiter that limits the gain. That is, the amplification device 200 can perform an amplification operation in response to a signal input having a large dynamic range. Therefore, by providing such an amplifying device 200 in the down converter 130, the down converter 130 can cope with an input signal having a large dynamic range.

  That is, when downconverter 130 receives a weak signal such as noise while searching for a wireless signal, amplifying apparatus 200 operates in the fixed gain region. When the down converter 130 receives a signal that is several orders of magnitude or more larger than noise in a state where the satellite 10 can be captured and communicated, the amplifying device 200 operates in the limit region. Thus, the downconverter 130 can stably extract the modulated signal from the received signal and appropriately execute communication with the satellite 10 without generating a signal that is large enough to destroy a subsequent circuit or the like.

  Also, in the amplifying device 200 according to the present embodiment, the first attenuator 210 used for limiting the gain is provided in a stage preceding the amplifier 220. Accordingly, even if the input signal becomes larger than the first strength, the signal attenuated by the first attenuator 210 can be supplied to the amplifier 220, and the signal larger than the first strength is input to the amplifier 220. Can be prevented. Further, when the input signal becomes smaller than the first intensity, the first attenuation of the first attenuator 210 becomes minimum. Therefore, when operating at a fixed gain, the amplifying device 200 minimizes the loss at the preceding stage of the amplifier 220, so that the small signal amplifying operation can be performed with the NF minimized.

  It has been described that the amplifying device 200 according to the above-described embodiment functions as a limiter that limits the gain when the input signal is a signal large enough to exceed the first intensity. In this case, the amplifying device 200 can output a signal having a substantially constant reference intensity even if the input signal fluctuates due to temperature fluctuation, environmental fluctuation, successive change, and the like.

  In addition, the amplification device 200 may cause the storage unit 270 to store a correction value corresponding to such a change. That is, in the amplifying device 200, even if there is a change in temperature or the like, the second signal generation unit 280 supplies a second control signal corresponding to the change to the second attenuator 230. This allows the amplification device 200 to stably execute the small signal amplification operation in the fixed gain region even when the input signal fluctuates. In this case, it is preferable that the amplifying device 200 further include a sensor that detects a change in an input signal or an environment.

  In the amplifying apparatus 200 according to the present embodiment, the example in which the second attenuator 230 is a variable attenuator has been described, but the present invention is not limited to this. The second attenuator 230 may be an attenuator having a fixed attenuation.

  As described above, the present invention has been described using the embodiment, but the technical scope of the present invention is not limited to the scope described in the above embodiment, and various modifications and changes are possible within the scope of the gist. is there. For example, the specific embodiment of the dispersion / integration of the apparatus is not limited to the above embodiment, and all or a part of the apparatus may be functionally or physically dispersed / integrated in an arbitrary unit. Can be. Further, new embodiments that are generated by arbitrary combinations of the plurality of embodiments are also included in the embodiments of the present invention. The effect of the new embodiment caused by the combination has the effect of the original embodiment.

Reference Signs List 10 satellite 100 ground station 110 antenna 120 input / output circuit 121 circulator 122 input filter 123 input amplifier 124 output amplifier 125 output filter 130 down converter 131 first isolator 132 first amplifier 133 signal generator 134 mixer 135 filter 136 second amplifier 140 signal processing unit 150 up-converter 200 amplifying device 210 first attenuator 220 amplifier 230 second attenuator 240 branch unit 250 detection unit 260 first signal generation unit 262 reference voltage source 270 storage unit 280 second signal generation unit 290 second isolator

Claims (7)

A first attenuator that attenuates an input signal by a first attenuation amount according to a first control signal and outputs a first attenuation signal;
An amplifier for amplifying the first attenuated signal and outputting an amplified signal;
A second attenuator that attenuates the amplified signal output from the amplifier by a predetermined second attenuation amount and outputs a second attenuated signal;
An amplification device comprising: a first signal generation unit that generates the first control signal based on a result of comparing the intensity of the second attenuation signal with a predetermined reference intensity of the signal. The first signal generation unit generates the first control signal for increasing the first attenuation when the intensity of the second attenuation signal is greater than the reference intensity, and generates the first control signal for increasing the first attenuation. When the intensity is smaller than the reference intensity, generating the first control signal for reducing the first attenuation amount;
The amplification device according to claim 1. A second signal generation unit that generates a second control signal that controls an amount of attenuation of the second attenuator;
The amplification device according to claim 1, wherein the second attenuator attenuates the amplified signal by the second attenuation amount according to the second control signal.   The amplification device according to any one of claims 1 to 3, further comprising a detection unit configured to detect the intensity of the second attenuation signal based on a part of the power extracted from the second attenuation signal.   The amplification device according to claim 1, further comprising a storage unit configured to store a value indicating the second attenuation amount determined in a state where the first attenuation amount is a minimum. A signal generator for generating a predetermined frequency signal,
A mixer unit that mixes the predetermined frequency signal and an input high-frequency signal to generate a mixing signal;
A down converter, comprising: the amplifier according to claim 1, wherein the down converter receives the mixing signal as the input signal. An antenna that receives a radio signal from a satellite and converts it into an electric signal;
A receiving device comprising: the down converter according to claim 6, wherein the down converter receives the electric signal as the high-frequency signal.

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