Satellite-borne digital SAR antenna module based on chip TR assembly

Abstract

The invention relates to the technical field of satellite synthetic aperture radar antennas, in particular to a spaceborne digital SAR (synthetic aperture radar) antenna module based on a chip TR (transmitter / receiver) component, comprising an extensible array module which comprises a last-stage power amplifier core group, a receiving front-end core group, an amplitude-phase and first-stage delay multifunctional core group and a second-stage delay amplification core group; the low-power radio frequency module comprises a photoelectric conversion and electro-optical conversion module, a phase-locked synthesis module, a digital transceiver module and an analog transceiver module; a multi-channel broadband digital transmit-receive synchronization module, wherein the multi-channel broadband digital transmit-receive synchronization module comprises an on-satellite computing device module; and the antenna module comprises a protocol analysis module and a beam control module. According to the antenna module provided by the invention, a high-performance and high-integration SAR antenna can be rapidly integrated, the number of the antenna modules can be selected according to required antenna performance indexes, the antenna modules can be flexibly combined and spliced, and market requirements can be rapidly met.

Description

Technical Field

[0001] The present invention relates to the technical field of satellite synthetic aperture radar antennas, and in particular to a satellite-borne digital SAR antenna module based on a chip TR component. Background Art

[0002] The SAR antenna is the core of the SAR satellite. Its cost and weight usually account for more than half of the entire satellite. The performance of the antenna will directly determine the satellite's imaging capability. The current mainstream SAR antenna mainly adopts an analog phased array system based on brick-type TR components, which has problems such as low integration and heavy weight. The highly integrated digital SAR antenna technology based on high-power chip TR components is a common key core technology for SAR satellites. It can improve the antenna integration, reduce the antenna size and weight, and meet the modularization and scale requirements of future commercial satellites. The relevant technical difficulties are reflected in the following aspects:

[0003] 1. Traditional brick-type TR components have low integration and heavy weight

[0004] Foreign countries started research on active phased arrays early, and the development of the core RF transceiver components in active phased arrays has experienced a transition from brick-type to chip-type (also known as tile-type). Brick-type components are relatively simple in design and easy to assemble, but the integration of brick-type components is generally not high, and they do not have advantages in weight and volume, which does not conform to the development trend of miniaturization and lightweight of active phased arrays. Therefore, RF transceiver components are gradually developing towards low-profile, small-volume tile-type components.

[0005] 2. Traditional analog radar antenna interconnection high-frequency cables are complex and have poor instantaneous dynamic range performance

[0006] The sub-arrays of traditional analog radar antennas are connected by high-frequency cables, and the analog signals are synthesized uniformly in the radar control system. The high-frequency cables of each sub-array are complex, and the dynamic range of analog synthesis is limited. The digital array radar antenna is a fully digital array scanning radar that uses digital beamforming technology for both receiving and transmitting beams. Compared with analog radars, digital radars can use computers to control the system and signal processing. The sub-arrays and the control system are connected by optical fiber digital signals. Through digital synthesis, it can better resist radio frequency interference and detect weak targets in strong clutter, significantly improving the instantaneous dynamic range. Summary of the invention

[0007] The purpose of the present invention is to solve the problems existing in the prior art and to propose a space-borne digital SAR antenna module based on a chip TR component.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A spaceborne digital SAR antenna module based on a chip TR component, comprising:

[0010] An expandable array module, the expandable array module comprising a final power amplifier core group, a receiving front-end core group, an amplitude-phase and first-stage delay multifunctional core group, and a second-stage delay amplifier core group;

[0011] A low-power radio frequency module, the low-power radio frequency module comprising a photoelectric conversion and electro-optical conversion module, a phase-locked synthesis module, a digital transceiver module and an analog transceiver module;

[0012] A multi-channel broadband digital transceiver synchronization module, wherein the multi-channel broadband digital transceiver synchronization module comprises an on-board computing device module;

[0013] The antenna module comprises a protocol analysis module, a beam control module, a digital receiving module, a signal generating module, an amplitude measuring module and a status monitoring module.

[0014] Preferably, the output pulse power of the final power amplifier core group is 20W, and a GaN power amplifier is selected;

[0015] The receiving front-end core group adopts a balanced amplification mode. When the antenna port is open during transmission, the reflected signal is reflected again by the limiter and can be absorbed by the load of the lange coupler to protect the power amplifier and low noise amplifier components.

[0016] The amplitude, phase and first-level delay multifunctional core group mainly completes first-level 1-division and 2-power division, 6-bit digitally controlled attenuation, 6-bit digitally controlled phase shift, 3-bit first-level digitally controlled delay and transceiver switch switching. Silicon-based integrated stacked core groups are selected to achieve microwave link cavity division and miniaturization design goals.

[0017] Preferably, the photoelectric conversion and electro-optical conversion modules mainly complete the photoelectric conversion and electro-optical conversion of the echo signal, wave control parameters, and reference signal, and perform long-distance signal transmission through optical fiber;

[0018] The phase-locked synthesis module synthesizes the sampling clock and frequency-converting local oscillator signal required inside the low-power radio frequency based on the reference signal, adopts the sampling phase-locked implementation mode, reduces the circuit complexity, and improves the integration of the low-power radio frequency while obtaining high performance through single-chip integration;

[0019] The digital transceiver module completes the acquisition and digital demodulation of SAR echoes. The digitally demodulated echo signals are sent to the onboard computer via optical fiber, and at the same time, the control function of the expandable array module is completed within the standard module.

[0020] The analog transceiver module completes the amplification, up-conversion and filtering of the radar excitation signal, and completes the analog down-conversion, amplification and filtering of the radar echo.

[0021] Preferably, the protocol analysis module mainly completes the analysis of information such as wave control codes and waveform parameters input by the on-board computing device, and the antenna module completes the digital generation of radiation signals and the digital reception of echo signals under the control of these information.

[0022] Preferably, the beam control module, driven by the working timing of the SAR antenna system, inputs the parsed beam control code value into the TR component, controls the attenuator and phase shifter in the TR component, and forms the transmitting and receiving beams required by the SAR antenna.

[0023] Preferably, the digital receiving module completes the acquisition, digital down-conversion, digital filtering and data transmission of the echo signal according to the protocol parsing parameters.

[0024] Preferably, the signal generating module completes the digital generation of the SAR antenna excitation signal according to the protocol parsing parameters, and generates a transmission signal that meets the imaging requirements of different modes.

[0025] Preferably, the amplitude measurement module performs amplitude calculation on the baseband echo data, and controls the gain of the radio frequency link in a closed loop according to the calculated value, so that the echo signal is not saturated, thereby realizing the automatic gain control function of the SAR antenna; at the same time, the amplitude of each receiving and transmitting channel signal is measured in the calibration mode, and the amplitude and phase calibration of each receiving and transmitting channel of the SAR antenna is completed.

[0026] Preferably, the status monitoring module checks the status of each functional circuit inside the standard antenna module based on a built-in self-check method, and comprehensively identifies the fault phenomenon and takes corresponding treatment measures through a health management strategy.

[0027] Preferably, the on-board computing device module uniformly provides timing reference and parameter reference. These reference signals are modulated onto optical signals together and transmitted to the antenna module over long distances via optical fiber. The antenna module performs photoelectric conversion and extracts timing reference and reference reference. The timing reference is used to control synchronous reception and transmission inside the standard antenna module. The reference reference is used to provide a reference for the phase-locked synthesis module, generate a clock network module for digital sampling, and realize synchronous acquisition and generation of multi-channel received signals.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] 1. The antenna module proposed in the present invention can quickly integrate a high-performance, highly integrated SAR antenna. The number of antenna modules can be flexibly combined and spliced ​​according to the required antenna performance indicators to quickly meet market demand.

[0030] 2. Due to the technical advantages of the antenna module proposed in the present invention, the development cost and development cycle of the SAR antenna can be reduced, the ability of the SAR antenna to identify targets in complex backgrounds can be improved, and the imaging performance of the SAR antenna can be improved.

[0031] 3. The technical point of the present invention is to integrate the component receiving channel, transmitting channel, amplitude shift, phase shift, delay amplification and other functional modules through a chip, and the transceiver channel completes the analog-to-digital conversion inside the module and is connected to the outside through a standard digital interface.

[0032] 4. The antenna module proposed in this invention has an instantaneous dynamic range of 50dB through simulation analysis, which is about 13dB higher than the traditional antenna module. The power density of the antenna module is 4kw / m 2 , 1.5kw / m higher than traditional antenna modules 2 about. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a functional block diagram of an expandable array module in a spaceborne digital SAR antenna module based on a chip TR component proposed by the present invention;

[0034] Figure 2 It is a functional block diagram of 8 TR channels in the expandable array module;

[0035] Figure 3 This is a principle block diagram of a low-power radio frequency module in a satellite-borne digital SAR antenna module based on a chip-based TR component proposed by the present invention;

[0036] Figure 4 This is a principle block diagram of a multi-channel digital transceiver synchronization module in a spaceborne digital SAR antenna module based on a chip TR component proposed by the present invention;

[0037] Figure 5 This is a schematic diagram of the internal and external interfaces of an antenna module in a space-borne digital SAR antenna module based on a chip-based TR component proposed by the present invention. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Reference Figure 1-Figure 5, a spaceborne digital SAR antenna module based on chip TR components, including an expandable array module, the expandable array module includes a final power amplifier core group, a receiving front-end core group, an amplitude, phase and first-level delay multifunctional core group and a second-level delay amplifier core group;

[0040] Low-power radio frequency module, which includes photoelectric conversion and electro-optical conversion modules, phase-locked synthesis modules, digital transceiver modules and analog transceiver modules;

[0041] A multi-channel broadband digital transceiver synchronization module, the multi-channel broadband digital transceiver synchronization module includes an on-board computing device module;

[0042] Antenna module, the antenna module includes a protocol analysis module, a beam control module, a digital receiving module, a signal generation module, an amplitude measurement module and a status monitoring module.

[0043] The output pulse power of the final power amplifier core group is 20W, and GaN power amplifier is selected;

[0044] The receiving front-end core group adopts balanced amplification mode. When the antenna port is open during transmission, the reflected signal is reflected by the limiter again and can be absorbed by the load of the lange coupler to protect the power amplifier and low noise amplifier components.

[0045] The amplitude, phase and first-level delay multifunctional core group mainly completes the first-level 1-division and 2-power division, 6-bit numerically controlled attenuation, 6-bit numerically controlled phase shift, 3-bit first-level numerically controlled delay and transceiver switch switching. Silicon-based integrated stacked core group is selected to achieve the microwave link cavity division and miniaturization design goals.

[0046] Furthermore, the expandable array module receives low-power RF input clock, data and enable signals to perform the following functions:

[0047] 1) Multi-channel integration: 8 TR channels for transmission and reception, each channel can be switched on and off independently;

[0048] 2) Amplitude and phase adjustment: Each channel can independently perform 6-bit digital controlled attenuation and 6-bit digital controlled phase shift;

[0049] 3) Two-level time delay adjustment: 3bit first-level digital control delay (0.5λ, 0.5λ, 1λ); 3bit second-level digital control delay (2λ, 4λ, 8λ) on public roads;

[0050] 4) Transmit / receive switching: realize the switching between transmitting and receiving states. The control codes such as amplitude, phase, delay and RF switch are preset in advance to realize fast switching;

[0051] 5) Transmit and receive pulse modulation: The internal circuit performs pulse modulation on the transmission and reception to meet the top drop requirements;

[0052] 6) Fast charging and discharging of transmission and reception: Adopting energy storage and discharge circuit, it has the ability of fast and stable transmission and reception;

[0053] 7) Transceiver calibration: realize the transceiver calibration of each channel through the coupling port;

[0054] 8) Multi-mode operation: The components can be set to different modes such as transmission, reception and standby;

[0055] 9) Consider functions such as fault isolation, negative pressure protection, and full reflection protection;

[0056] 10) Consider space environment design requirements such as onboard temperature, radiation, EMC and ESD.

[0057] Taking into account the chip and graphic size of the characteristic frequency, the heat dissipation requirements under high output power, and packaging standardization, a one-to-two component-level implementation is adopted. Specifically, a dual-channel multifunctional packaged chip with integrated attenuation, amplification, shift delay, etc. is connected to two packaged chips with integrated PA and LNA, and the switch chip can be replaced with a circulator.

[0058] The photoelectric conversion and electro-optical conversion modules mainly complete the photoelectric conversion and electro-optical conversion of echo signals, wave control parameters, and reference signals, and perform long-distance signal transmission through optical fibers;

[0059] The phase-locked synthesis module synthesizes the sampling clock and frequency-converting local oscillator signal required by the low-power RF based on the reference signal, and adopts the sampling phase-locked implementation method to reduce the circuit complexity. Through single-chip integration, it improves the integration of low-power RF while achieving high performance;

[0060] The digital transceiver module completes the acquisition and digital demodulation of SAR echoes. The digitally demodulated echo signals are sent to the onboard computer via optical fiber, while also completing the control function of the expandable array module within the standard module.

[0061] The analog transceiver module completes the amplification, up-conversion and filtering of the radar excitation signal, and completes the analog down-conversion, amplification and filtering of the radar echo.

[0062] The protocol analysis module is mainly used to analyze the wave control codes, waveform parameters and other information input by the onboard computing equipment. The antenna module completes the digital generation of the radiation signal and the digital reception of the echo signal under the control of this information.

[0063] Driven by the working timing of the SAR antenna system, the beam control module inputs the parsed wave control code value into the TR component, controls the attenuator and phase shifter in the TR component, and forms the transmit and receive beams required by the SAR antenna.

[0064] The digital receiving module parses the parameters according to the protocol and completes the acquisition, digital down-conversion, digital filtering and data transmission of the echo signal.

[0065] The signal generation module digitizes the SAR antenna excitation signal according to the protocol parsing parameters, and generates a transmission signal that meets the imaging requirements of different modes.

[0066] The amplitude measurement module calculates the amplitude of the baseband echo data, and controls the gain of the RF link in a closed loop according to the calculated value, so that the echo signal is not saturated, thereby realizing the automatic gain control function of the SAR antenna. At the same time, the amplitude of each receiving and transmitting channel signal is measured in the calibration mode to complete the amplitude and phase calibration of each receiving and transmitting channel of the SAR antenna.

[0067] The status monitoring module checks the status of each functional circuit inside the standard antenna module based on the built-in self-test method, and uses the health management strategy to comprehensively identify the fault phenomenon and take corresponding treatment measures.

[0068] The onboard computing device module uniformly provides timing reference and parameter reference. These reference signals are modulated onto optical signals and transmitted to the antenna module over long distances via optical fiber. The antenna module performs photoelectric conversion and extracts timing reference and reference reference. The timing reference is used to control synchronous reception and transmission inside the standard antenna module. The reference reference is used to provide a reference for the phase-locked synthesis module and to generate a clock network module for digital sampling, thereby realizing synchronous acquisition and generation of multi-channel received signals.

[0069] The antenna module prepared in the present invention can quickly integrate a high-performance, highly integrated SAR antenna, and can flexibly combine and splice the number of antenna modules according to the required antenna performance indicators to quickly meet market demand;

[0070] Due to the technical advantages of the antenna module proposed in the present invention, the development cost and development cycle of the SAR antenna can be reduced, the ability of the SAR antenna to identify targets under complex backgrounds can be improved, and the imaging performance of the SAR antenna can be improved;

[0071] In addition, the instantaneous dynamic range of the antenna module proposed in the invention is 50dB through simulation analysis, which is about 13dB higher than that of the traditional antenna module. The power density of the antenna module is 4kw / m 2 , 1.5kw / m higher than traditional antenna modules 2 about.

[0072] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A spaceborne digital SAR antenna module based on a chip TR component, characterized in that: include: An expandable array module, the expandable array module comprising a final power amplifier core group, a receiving front-end core group, an amplitude-phase and first-stage delay multifunctional core group, and a second-stage delay amplifier core group; A low-power radio frequency module, the low-power radio frequency module comprising a photoelectric conversion and electro-optical conversion module, a phase-locked synthesis module, a digital transceiver module and an analog transceiver module; A multi-channel broadband digital transceiver synchronization module, wherein the multi-channel broadband digital transceiver synchronization module comprises an on-board computing device module; The antenna module comprises a protocol analysis module, a beam control module, a digital receiving module, a signal generating module, an amplitude measuring module and a status monitoring module.

2. The spaceborne digital SAR antenna module based on a chip TR component according to claim 1, characterized in that: The output pulse power of the final power amplifier core group is 20W, and a GaN power amplifier is selected; The receiving front-end core group adopts a balanced amplification mode. When the antenna port is open during transmission, the reflected signal is reflected by the limiter again and can be absorbed by the load of the lange coupler to protect the power amplifier and low noise amplifier components. The amplitude, phase and first-level delay multifunctional core group mainly completes the first-level 1-division 2-power division, 6-bit digitally controlled attenuation, 6-bit digitally controlled phase shift, 3-bit first-level digitally controlled delay and transceiver switch switching. Silicon-based integrated stacked core group is selected to achieve the microwave link cavity division and miniaturization design goals.

3. The spaceborne digital SAR antenna module based on a chip TR component according to claim 1, characterized in that: The photoelectric conversion and electro-optical conversion modules mainly complete the photoelectric conversion and electro-optical conversion of echo signals, wave control parameters, and reference signals, and perform long-distance signal transmission through optical fibers; The phase-locked synthesis module synthesizes the sampling clock and frequency-converting local oscillator signal required inside the low-power radio frequency based on the reference signal, adopts the sampling phase-locked implementation mode, reduces the circuit complexity, and improves the integration of the low-power radio frequency while obtaining high performance through single-chip integration; The digital transceiver module completes the acquisition and digital demodulation of SAR echoes. The digitally demodulated echo signals are sent to the onboard computer via optical fiber, and at the same time, the control function of the expandable array module is completed within the standard module. The analog transceiver module completes the amplification, up-conversion and filtering of the radar excitation signal, and completes the analog down-conversion, amplification and filtering of the radar echo.

4. The spaceborne digital SAR antenna module based on a chip TR component according to claim 1, characterized in that: The protocol analysis module mainly completes the analysis of information such as wave control codes and waveform parameters input by the on-board computing device, and the antenna module completes the digital generation of radiation signals and the digital reception of echo signals under the control of these information.

5. The spaceborne digital SAR antenna module based on a chip TR component according to claim 4, characterized in that: Driven by the working timing of the SAR antenna system, the beam control module inputs the parsed beam control code value into the TR component, controls the attenuator and phase shifter in the TR component, and forms the transmission and reception beams required by the SAR antenna.

6. The spaceborne digital SAR antenna module based on a chip TR component according to claim 5, characterized in that: The digital receiving module completes the acquisition, digital down-conversion, digital filtering and data transmission of the echo signal according to the protocol parsing parameters.

7. The spaceborne digital SAR antenna module based on a chip TR component according to claim 6, characterized in that: The signal generation module completes the digital generation of the SAR antenna excitation signal according to the protocol parsing parameters, and generates a transmission signal that meets the imaging requirements of different modes.

8. The spaceborne digital SAR antenna module based on a chip TR component according to claim 7, characterized in that: The amplitude measurement module calculates the amplitude of the baseband echo data, and controls the gain of the radio frequency link in a closed loop according to the calculated value, so that the echo signal is not saturated, thereby realizing the automatic gain control function of the SAR antenna; at the same time, the amplitude of each receiving and transmitting channel signal is measured in the calibration mode, and the amplitude and phase calibration of each receiving and transmitting channel of the SAR antenna is completed.

9. The spaceborne digital SAR antenna module based on chip TR components according to claim 8, characterized in that: The status monitoring module checks the status of each functional circuit inside the standard antenna module based on the built-in self-check method, and comprehensively judges the fault phenomenon and takes corresponding treatment measures through the health management strategy.

10. The spaceborne digital SAR antenna module based on a chip TR component according to claim 1, characterized in that: The on-board computing device module uniformly provides timing reference and parameter reference. These reference signals are modulated onto optical signals and transmitted to the antenna module over long distances via optical fiber. The antenna module performs photoelectric conversion and extracts timing reference and reference reference. The timing reference is used to control the standard antenna module to achieve synchronous reception and transmission. The reference reference is used to provide a reference for the phase-locked synthesis module, generate a clock network module for digital sampling, and achieve synchronous acquisition and generation of multi-channel received signals.

Images