A phased array RF front end for Ka-band satellite communications

Abstract

The present invention discloses a Ka-band satellite communication phased array radio frequency front end, belonging to the field of satellite communication. It is composed of an up-conversion module, a Ka-band transmitting phased array antenna, a Ka-band receiving phased array antenna, a down-conversion module, a control circuit, a combined navigation circuit and the like. It controls the frequency, gain and antenna pointing through a network port, and internally realizes the purpose of up-conversion and Ka-band transmission of satellite communication uplink signals and Ka-band reception and down-conversion of downlink signals by an up-conversion module, a Ka-band transmitting phased array antenna, a Ka-band receiving phased array antenna, a down-conversion module, a control circuit and a combined navigation circuit. The present invention has the advantages of high operating frequency, wide bandwidth, high integration, small size, light weight, stable and reliable performance, etc. It can work normally in harsh outdoor environments, and is particularly suitable for use as a Ka-band radio frequency front end for high-orbit or low-orbit satellite communication ground terminal stations.

Description

Technical Field

[0001] The present invention relates to the field of satellite communications, and in particular to a Ka-band satellite communication phased array radio frequency front end, which can be used for a ground terminal station of high-orbit or low-orbit satellite communications. Background Art

[0002] With the development of satellite communications, the demand for satellite communication systems to support high orbit, low orbit, and high and low orbit at the same time is becoming more and more urgent. In particular, low-orbit satellite communications require beams to be flexibly pointed to fast-moving satellites. At present, the RF front end used for satellite communications mainly uses parabolic antennas, and the beam pointing is a mechanical rotation method with poor flexibility. In particular, beam switching requires dual parabolic antennas, which have a high profile, large volume, and poor portability. Summary of the invention

[0003] The technical problem to be solved by the present invention is to avoid the deficiencies in the above-mentioned background technology and provide a Ka-band satellite communication phased array RF front end. The present invention has the advantages of high operating frequency, wide bandwidth, high integration, small size, light weight, stable and reliable performance, etc.

[0004] The technical solution adopted by the present invention is:

[0005] A Ka-band satellite communication phased array radio frequency front end, comprising a Ka-band transmitting phased array antenna 2, a Ka-band receiving phased array antenna 3, a control circuit 5 and a combined navigation circuit 6, and also comprising an up-conversion module 1 and a down-conversion module 4;

[0006] The up-conversion module 1 is used to attenuate and amplify the externally input C-band uplink intermediate frequency signal according to the control signal input by the control circuit 5, and up-convert the amplified and attenuated signal to the Ka-band uplink radio frequency signal, and then output it to the Ka-band transmitting phased array antenna 2 after amplification and filtering;

[0007] The Ka-band transmitting phased array antenna 2 is used to amplify the Ka-band uplink radio frequency signal according to the control signal input by the control circuit 5, and transmit the amplified Ka-band uplink radio frequency signal to the specified satellite direction through beam air synthesis;

[0008] The Ka-band receiving phased array antenna 3 is used to receive the specified airborne Ka-band downlink satellite signal according to the control signal input by the control circuit 5, and amplify the received Ka-band downlink satellite signal and output it to the down-conversion module 4;

[0009] The down-conversion module 4 is used to amplify and filter the Ka-band downlink RF signal output by the Ka-band receiving phased array antenna 3 according to the control signal input by the control circuit 5, and down-convert the amplified and filtered signal to a C-band downlink intermediate frequency signal, and then output it after filtering, attenuation and amplification;

[0010] The control circuit 5 is used to receive external instructions and position information of the integrated navigation circuit 6, and convert them into internal control signals to control the frequency and gain of the up-conversion module 1 and the down-conversion module 4, as well as the beam pointing of the Ka-band transmitting phased array antenna 2 and the Ka-band receiving phased array antenna 3;

[0011] The integrated navigation circuit 6 is used to calculate and indicate current position information and transmit the position information to the control circuit 5 .

[0012] Furthermore, the up-conversion module 1 includes a first digitally controlled attenuation circuit 7, a first intermediate frequency amplifier circuit 8, a first mixing circuit 9, a first radio frequency filter circuit 10, an analog attenuation circuit 11, a first radio frequency amplifier circuit 12, a first isolator 13, a first double frequency circuit 14, and a first local oscillator circuit 15;

[0013] The first digitally controlled attenuation circuit 7 is used to attenuate the C-band uplink intermediate frequency signal input from the external interface according to the instruction of the control circuit 5, and then output it to the first intermediate frequency amplification circuit 8;

[0014] The first intermediate frequency amplifier circuit 8 is used to amplify the C-band uplink intermediate frequency signal output by the first digitally controlled attenuation circuit 7, and then output it to the first mixer circuit 9;

[0015] The first mixing circuit 9 is used to mix the C-band uplink intermediate frequency signal output by the first intermediate frequency amplifier circuit 8 with the local oscillator double frequency signal output by the first double frequency circuit 14, and then output the Ka-band uplink radio frequency signal to the first radio frequency filter circuit 10;

[0016] The first RF filter circuit 10 is used to filter the Ka-band uplink RF signal output by the first mixer circuit 9, filter out out-of-band spurious signals, and then output it to the analog attenuation circuit 11;

[0017] The analog attenuation circuit 11 is used to simulate the attenuation of the Ka-band uplink RF signal output by the first RF filter circuit 10 to a specified power, and then output it to the first RF amplification circuit 12;

[0018] The first radio frequency amplifier circuit 12 is used to amplify the Ka-band uplink radio frequency signal output by the analog attenuation circuit 11, and then output it to the first isolator 13;

[0019] The first isolator 13 is used to perform impedance matching on the Ka-band uplink RF signal output by the first RF amplification circuit 12, and then output it to the Ka-band transmitting phased array antenna 2;

[0020] The first double frequency circuit 14 is used for doubling the frequency of the local oscillator signal output by the first local oscillator circuit 15, and outputting the doubled local oscillator signal to the first mixer circuit 9;

[0021] The first local oscillator circuit 15 is used to output a local oscillator signal with a variable frequency to the first double frequency circuit 14 according to the instruction of the control circuit 5 .

[0022] Further, the down-conversion module 4 includes a second isolator 16, a second RF amplifying circuit 17, a second RF filtering circuit 18, a second mixing circuit 19, an intermediate frequency filtering circuit 20, a second digitally controlled attenuation circuit 21, a second intermediate frequency amplifying circuit 22, a second double frequency circuit 23, and a second local oscillator circuit 24;

[0023] The second isolator 16 is used to perform impedance matching on the Ka-band downlink RF signal output by the Ka-band receiving phased array antenna 3, and then output it to the second RF amplification circuit 17;

[0024] The second RF amplifier circuit 17 is used to amplify the Ka-band downlink RF signal output by the second isolator 16, and then output it to the second RF filter circuit 18;

[0025] The second RF filter circuit 18 is used to filter the Ka-band downlink RF signal output by the second RF amplifier circuit 17, filter out out-of-band spurious signals, and then output it to the second mixer circuit 19;

[0026] The second mixing circuit 19 is used to mix the Ka-band downlink RF signal output by the second RF filter circuit 18 with the local oscillator 2-times-frequency signal output by the second 2-times-frequency circuit 23, and output a C-band downlink intermediate frequency signal to the intermediate frequency filter circuit 20;

[0027] The intermediate frequency filter circuit 20 is used to filter the C-band downlink intermediate frequency signal output by the second mixer circuit 19, filter out out-of-band spurious signals, and then output it to the second digitally controlled attenuation circuit 21;

[0028] The second digitally controlled attenuation circuit 21 is used to attenuate the C-band downlink intermediate frequency signal input by the intermediate frequency filter circuit 20 according to the instruction of the control circuit 5, and then output it to the second intermediate frequency amplification circuit 22;

[0029] The second intermediate frequency amplifier circuit 22 is used to amplify the C-band downlink intermediate frequency signal output by the second digitally controlled attenuation circuit 21, and then output it to the external interface;

[0030] The second double frequency circuit 23 is used for doubling the frequency of the local oscillation signal output by the second local oscillation circuit 24, and outputting the doubled local oscillation signal to the second mixer circuit 19;

[0031] The second local oscillator circuit 24 is used to output a local oscillator signal with a variable frequency to the second double frequency circuit 23 according to the instruction of the control circuit 5 .

[0032] Compared with the background technology, the present invention has the following advantages:

[0033] 1. The present invention has a simple and compact structure, low cost, is easy to manufacture, can achieve a high degree of integration, is easy to achieve miniaturization, and has promotion and application value.

[0034] 2. The up-conversion module 1 and the down-conversion module 4 of the present invention have simple structures and can be manufactured using a micro-assembly process. Thus, they have the advantages of small size and light weight while meeting satellite communication channel indicators, and are easy to integrate.

[0035] 3. The present invention has a simple structure and a small debugging workload, and can work normally in a relatively harsh ambient temperature of -40°C to +55°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a principle block diagram of a Ka-band satellite communication phased array RF front end.

[0037] Figure 2 yes Figure 1 Electrical schematic diagram of mid-up frequency conversion module 1.

[0038] Figure 3 yes Figure 1 Electrical schematic diagram of mid-down frequency conversion module 4. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with the accompanying drawings.

[0040] A Ka-band satellite communication phased array radio frequency front end comprises an up-conversion module 1, a Ka-band transmitting phased array antenna 2, a Ka-band receiving phased array antenna 3, a down-conversion module 4, a control circuit 5 and a combined navigation circuit 6. Figure 1 is an electrical principle block diagram of an embodiment of the present invention, and the embodiment is as follows Figure 1 Connect the lines.

[0041] Among them, the up-conversion module 1 is used to attenuate and amplify the externally input C-band uplink intermediate frequency signal according to the control signal input by the control circuit 5, and up-convert the amplified and attenuated signal to the Ka-band uplink RF signal, and then output it to the Ka-band transmitting phased array antenna 2 after amplification and filtering.

[0042] The Ka-band transmitting phased array antenna 2 is used to amplify the Ka-band uplink radio frequency signal according to the control signal input by the control circuit 5, and transmit the amplified Ka-band uplink radio frequency signal to the designated satellite direction by beam synthesis in the air. In this embodiment, the Ka-band transmitting phased array antenna 2 is made of a commercially available dedicated phased array sub-array TENSU-A1024T.

[0043] The Ka-band receiving phased array antenna 3 is used to synthesize beams to receive designated airborne Ka-band downlink satellite signals according to the control signal input by the control circuit 5, and to amplify the received Ka-band downlink satellite signals and output them to the down-conversion module 4. In this embodiment, the Ka-band receiving phased array antenna 3 is made of a commercially available dedicated phased array sub-array TENSU-A1024R.

[0044] The down-conversion module 4 is used to amplify and filter the Ka-band downlink RF signal output by the Ka-band receiving phased array antenna 3 according to the control signal input by the control circuit 5, and down-convert the amplified and filtered signal to a C-band downlink intermediate frequency signal, and the C-band downlink intermediate frequency signal is then filtered, attenuated and amplified for output.

[0045] The control circuit 5 is used to receive external instructions and position information of the integrated navigation circuit 6, and convert them into internal control signals to control the frequency and gain of the up-conversion module 1 and the down-conversion module 4, and the beam pointing of the Ka-band transmitting phased array antenna 2 and the Ka-band receiving phased array antenna 3. In this embodiment, the control circuit 5 is made of a commercially available dedicated chip ZYNQ7020.

[0046] The integrated navigation circuit 6 is used to calculate and indicate the current position information, and transmit the position information to the control circuit 5. In this embodiment, the integrated navigation circuit 6 is made of a commercially available dedicated navigation circuit KY-INS180-C0.

[0047] Figure 2 is an electrical schematic diagram of the up-conversion module 1, and the embodiment is as follows Figure 2 Connect the lines.

[0048] The up-conversion module 1 includes a first digitally controlled attenuation circuit 7, a first intermediate frequency amplifier circuit 8, a first mixing circuit 9, a first radio frequency filter circuit 10, an analog attenuation circuit 11, a first radio frequency amplifier circuit 12, a first isolator 13, a first double frequency circuit 14, and a first local oscillator circuit 15.

[0049] The first digitally controlled attenuation circuit 7 is used to attenuate the C-band uplink intermediate frequency signal input from the external interface according to the instruction of the control circuit 5, and output it to the first intermediate frequency amplifier circuit 8. In this embodiment, the first digitally controlled attenuation circuit 7 is made of a commercially available dedicated digitally controlled attenuator chip YG166SB-2.

[0050] The first intermediate frequency amplifier circuit 8 is used to amplify the C-band uplink intermediate frequency signal output by the first digitally controlled attenuation circuit 7 and output it to the first mixer circuit 9. In this embodiment, the intermediate frequency amplifier circuit 8 is made of a commercially available dedicated amplifier chip YFC5101-444A.

[0051] The first frequency mixer circuit 9 is used to mix the C-band uplink intermediate frequency signal output by the first intermediate frequency amplifier circuit 8 with the local oscillator double frequency signal output by the first double frequency circuit 14 to output a Ka-band uplink radio frequency signal, and output the Ka-band uplink radio frequency signal to the first radio frequency filter circuit 10. In this embodiment, the first frequency mixer circuit 9 is made of a commercially available dedicated mixer chip HGC518M.

[0052] The first RF filter circuit 10 is used to filter the Ka-band uplink RF signal output by the first mixer circuit 9, filter out out-of-band spurious signals, and output the signal to the analog attenuation circuit 11. In this embodiment, the first RF filter circuit 10 is made of a commercially available dedicated cavity filter BPF27.5-31GK-3848.

[0053] The analog attenuation circuit 11 is used to simulate the attenuation of the Ka-band uplink RF signal output by the first RF filter circuit 10 to a specified power and output it to the first RF amplifier circuit 12. In this embodiment, the analog attenuation circuit 11 is made of a commercially available dedicated analog attenuator chip NC13124C-2550.

[0054] The first radio frequency amplifier circuit 12 is used to amplify the Ka-band uplink radio frequency signal output by the analog attenuation circuit 11, and output it to the first isolator 13. In this embodiment, the first radio frequency amplifier circuit 12 is made of a commercially available dedicated amplifier chip NC10287C-2634.

[0055] The first isolator 13 is used to impedance match the Ka-band uplink RF signal output by the first RF amplifier circuit 12, and output it to the Ka-band transmitting phased array antenna 2. In this embodiment, the first isolator 13 is made of a commercially available dedicated microstrip isolator GW2543-63.

[0056] The first double frequency circuit 14 is used to double the frequency of the local oscillation signal output by the first local oscillation circuit 15, and output the doubled local oscillation signal to the first mixer circuit 9. In this embodiment, the first double frequency circuit 14 is made of a commercially available dedicated double frequency chip MW2113.

[0057] The first local oscillator circuit 15 is used to output a local oscillator signal with variable frequency according to the instruction of the control circuit 5, and output it to the first double frequency circuit 14. In this embodiment, the first local oscillator circuit 15 is made of a commercially available dedicated phase-locked loop circuit ADPLS-W1213-80-F1G-01.

[0058] Figure 3 is an electrical schematic diagram of the down-conversion module 4, and the embodiment is as follows Figure 3 Connect the lines.

[0059] The down-conversion module 4 includes a second isolator 16, a second RF amplifier circuit 17, a second RF filter circuit 18, a second mixer circuit 19, an intermediate frequency filter circuit 20, a second digitally controlled attenuation circuit 21, a second intermediate frequency amplifier circuit 22, a second double frequency circuit 23, and a second local oscillator circuit 24.

[0060] The second isolator 16 is used to impedance match the Ka-band downlink RF signal output by the Ka-band receiving phased array antenna 3 and output it to the second RF amplifier circuit 17. In this embodiment, the second isolator 16 is made of a commercially available dedicated microstrip isolator GW2543-41.

[0061] The second RF amplifier circuit 17 is used to amplify the Ka-band downlink RF signal output by the second isolator 16 and output it to the second RF filter circuit 18. In this embodiment, the second RF amplifier circuit 17 is made of a commercially available dedicated amplifier chip NC10219C-1826.

[0062] The second RF filter circuit 18 is used to filter the Ka-band downlink RF signal output by the second RF amplifier circuit 17, filter out out-of-band spurious signals, and output it to the second mixer circuit 19. In this embodiment, the second RF filter circuit 18 is made of a commercially available dedicated MEMS filter SiMF19R5 / 3-8D2.

[0063] The second frequency mixer circuit 19 is used to mix the Ka-band downlink RF signal output by the second RF filter circuit 18 with the local oscillator doubled frequency signal output by the second double frequency circuit 23 to output a C-band downlink intermediate frequency signal, and output the C-band downlink intermediate frequency signal to the intermediate frequency filter circuit 20. In this embodiment, the second frequency mixer circuit 19 is made of a commercially available dedicated mixer chip NC1733C-1328M.

[0064] The intermediate frequency filter circuit 20 is used to filter the C-band downstream intermediate frequency signal output by the second mixer circuit 19, filter out the out-of-band spurious signals and output them to the second digital controlled attenuation circuit 21. In this embodiment, the intermediate frequency filter circuit 20 is made of a commercially available dedicated filter chip NC6610C-050.

[0065] The second digitally controlled attenuation circuit 21 is used to attenuate the C-band downlink intermediate frequency signal input from the intermediate frequency filter circuit 20 according to the instruction of the control circuit 5, and output it to the second intermediate frequency amplifier circuit 22. In this embodiment, the second digitally controlled attenuation circuit 21 is made of a commercially available dedicated digitally controlled attenuator chip YG166SB-2.

[0066] The second intermediate frequency amplifier circuit 22 is used to amplify the C-band downstream intermediate frequency signal output by the second digitally controlled attenuation circuit 21 and output it to an external interface. In this embodiment, the second intermediate frequency amplifier circuit 22 is made of a commercially available dedicated amplifier chip YFC5101-444A.

[0067] The second double frequency circuit 23 is used to double the frequency of the local oscillator signal output by the second local oscillator circuit 24, and output the doubled local oscillator signal to the second mixer circuit 19. In this embodiment, the second double frequency circuit 23 is made of a commercially available dedicated double frequency chip NC1780C-1424B.

[0068] The second local oscillator circuit 24 is used to output a local oscillator signal with variable frequency according to the instruction of the control circuit 5, and output it to the second double frequency circuit 23. In this embodiment, the first local oscillator circuit 15 is made of a commercially available dedicated phase-locked loop circuit FS6775 / 8275-1.

[0069] The working principle of the present invention is briefly as follows: the externally input C-band uplink intermediate frequency signal is input from the input port A to the up-conversion module 1, and the up-conversion module 1 outputs the Ka-band uplink radio frequency signal of the specified frequency and power under the control of the control circuit 5. The Ka-band transmitting phased array antenna 2 amplifies the Ka-band uplink radio frequency signal according to the control signal input by the control circuit 5, and synthesizes the beam in the air and transmits it to the specified satellite direction. The Ka-band receiving phased array antenna 3 synthesizes the beam to receive the specified Ka-band downlink satellite signal in the air according to the control signal input by the control circuit 5, and outputs the received Ka-band downlink satellite signal to the down-conversion module 4. The down-conversion module 4 down-converts the Ka-band downlink radio frequency signal to a C-band downlink intermediate frequency signal according to the control signal input by the control circuit 5, and outputs it from the output port B. The combined navigation circuit 6 calculates and indicates the current position information, and transmits the position information to the control circuit 5. The control circuit 5 combines the ephemeris information provided by the external interface B to calculate the current satellite pointing direction, and sends it to the Ka-band transmitting phased array antenna 2 and the Ka-band receiving phased array antenna 3 respectively, to complete the antenna tracking and the reception and transmission of satellite signals.

[0070] The installation structure of the present invention is as follows: Figure 2 and Figure 3 All circuit components are installed in the shielding box through micro-assembly technology and printed circuit boards. Figure 1 All modules are installed in a 550mm×530mm×63mm waterproof and sealed structure. The modules are connected by transmission cables. The upper cover of the structure adopts a wave-transmitting antenna cover design. The lower part of the structure is a metal support structure, and heat is dissipated by fans and fins. The input port A and the output port C use TNC connectors, and the control port D uses an RJ45 connector to assemble the present invention.

[0071] The present invention controls the frequency, gain and antenna pointing through a network port, and internally realizes the purpose of up-conversion and Ka-band transmission of satellite communication uplink signals and Ka-band reception and down-conversion of downlink signals by an up-conversion module, a Ka-band transmitting phased array antenna, a Ka-band receiving phased array antenna, a down-conversion module, a control circuit and a combined navigation circuit.

[0072] In summary, the present invention has the advantages of high operating frequency, wide bandwidth, high integration, small size, light weight, stable and reliable performance, etc. It can work normally in harsh outdoor environments and is particularly suitable as a Ka-band RF front end for high-orbit or low-orbit satellite communication ground terminal stations.

Claims

1. A Ka-band satellite communication phased array radio frequency front end, comprising a Ka-band transmitting phased array antenna (2), a Ka-band receiving phased array antenna (3), a control circuit (5) and a combined navigation circuit (6), characterized in that: It also includes an up-conversion module (1) and a down-conversion module (4); The up-conversion module (1) is used to attenuate and amplify an externally input C-band uplink intermediate frequency signal according to a control signal input by a control circuit (5), and up-convert the amplified and attenuated signal to a Ka-band uplink radio frequency signal, and then amplify and filter and output it to the Ka-band transmitting phased array antenna (2); The Ka-band transmitting phased array antenna (2) is used to amplify the Ka-band uplink radio frequency signal according to the control signal input by the control circuit (5), and transmit the amplified Ka-band uplink radio frequency signal to the designated satellite direction through beam air synthesis; The Ka-band receiving phased array antenna (3) is used to receive a designated airborne Ka-band downlink satellite signal according to a control signal input by a control circuit (5), and to amplify the received Ka-band downlink satellite signal and output it to a down-conversion module (4); The down-conversion module (4) is used to amplify and filter the Ka-band downlink radio frequency signal output by the Ka-band receiving phased array antenna (3) according to the control signal input by the control circuit (5), and down-convert the amplified and filtered signal to a C-band downlink intermediate frequency signal, and then output it after filtering, attenuation and amplification; The control circuit (5) is used to receive external instructions and position information of the integrated navigation circuit (6), and convert them into internal control signals to control the frequency and gain of the up-conversion module (1) and the down-conversion module (4), as well as the beam pointing of the Ka-band transmitting phased array antenna (2) and the Ka-band receiving phased array antenna (3); The integrated navigation circuit (6) is used to calculate and indicate current position information and transmit the position information to the control circuit (5); The up-conversion module (1) comprises a first digitally controlled attenuation circuit (7), a first intermediate frequency amplification circuit (8), a first frequency mixing circuit (9), a first radio frequency filtering circuit (10), an analog attenuation circuit (11), a first radio frequency amplification circuit (12), a first isolator (13), a first double frequency circuit (14), and a first local oscillator circuit (15); The first digitally controlled attenuation circuit (7) is used to attenuate the C-band uplink intermediate frequency signal input from the external interface according to the instruction of the control circuit (5), and then output it to the first intermediate frequency amplification circuit (8); The first intermediate frequency amplifier circuit (8) is used to amplify the C-band uplink intermediate frequency signal output by the first digitally controlled attenuation circuit (7), and then output it to the first mixer circuit (9); The first mixing circuit (9) is used to mix the C-band uplink intermediate frequency signal output by the first intermediate frequency amplifier circuit (8) with the local oscillator double frequency signal output by the first double frequency circuit (14), and then output the Ka-band uplink radio frequency signal to the first radio frequency filter circuit (10); The first radio frequency filtering circuit (10) is used to filter the Ka-band uplink radio frequency signal output by the first mixing circuit (9), filter out out-of-band spurious signals, and then output the signal to the analog attenuation circuit (11); The analog attenuation circuit (11) is used to simulate the attenuation of the Ka-band uplink radio frequency signal output by the first radio frequency filter circuit (10) to a specified power, and then output it to the first radio frequency amplification circuit (12); The first radio frequency amplification circuit (12) is used to amplify the Ka-band uplink radio frequency signal output by the analog attenuation circuit (11), and then output it to the first isolator (13); The first isolator (13) is used to perform impedance matching on the Ka-band uplink radio frequency signal output by the first radio frequency amplification circuit (12), and then output it to the Ka-band transmitting phased array antenna (2); The first double frequency circuit (14) is used to double the frequency of the local oscillator signal output by the first local oscillator circuit (15), and output the doubled local oscillator signal to the first mixer circuit (9); The first local oscillator circuit (15) is used to output a local oscillator signal with a variable frequency to the first double frequency circuit (14) according to the instruction of the control circuit (5); The down-conversion module (4) comprises a second isolator (16), a second radio frequency amplification circuit (17), a second radio frequency filtering circuit (18), a second mixing circuit (19), an intermediate frequency filtering circuit (20), a second digitally controlled attenuation circuit (21), a second intermediate frequency amplification circuit (22), a second double frequency circuit (23), and a second local oscillator circuit (24); The second isolator (16) is used to perform impedance matching on the Ka-band downlink radio frequency signal output by the Ka-band receiving phased array antenna (3), and then output it to the second radio frequency amplification circuit (17); The second radio frequency amplification circuit (17) is used to amplify the Ka-band downlink radio frequency signal output by the second isolator (16), and then output it to the second radio frequency filtering circuit (18); The second radio frequency filtering circuit (18) is used to filter the Ka-band downlink radio frequency signal output by the second radio frequency amplifying circuit (17), filter out out-of-band spurious signals, and then output it to the second mixing circuit (19); The second mixing circuit (19) is used to mix the Ka-band downlink radio frequency signal output by the second radio frequency filtering circuit (18) with the local oscillator double frequency signal output by the second double frequency circuit (23), and output a C-band downlink intermediate frequency signal to the intermediate frequency filtering circuit (20); The intermediate frequency filter circuit (20) is used to filter the C-band downlink intermediate frequency signal output by the second mixer circuit (19), filter out out-of-band spurious signals, and then output it to the second digitally controlled attenuation circuit (21); The second digitally controlled attenuation circuit (21) is used to attenuate the C-band downlink intermediate frequency signal input from the intermediate frequency filter circuit (20) according to the instruction of the control circuit (5), and then output it to the second intermediate frequency amplification circuit (22); The second intermediate frequency amplifier circuit (22) is used to amplify the C-band downlink intermediate frequency signal output by the second digitally controlled attenuation circuit (21), and then output it to an external interface; The second double frequency circuit (23) is used to double the frequency of the local oscillator signal output by the second local oscillator circuit (24), and output the doubled local oscillator signal to the second mixer circuit (19); The second local oscillator circuit (24) is used to output a local oscillator signal with a variable frequency to the second double frequency circuit (23) according to the instruction of the control circuit (5).

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