Signal receiving and transmitting isolation suppression processing system and method for full duplex system

Abstract

The invention relates to a full-duplex system signal transceiving isolation suppression processing system and method, in particular to a signal transceiving isolation enhancement method applying antenna polarization isolation, microwave cavity band-pass filtering, multi-stage series FBAR band-stop filtering, multi-path parallel SAW narrow-band filtering and shunt digital filtering processing modes, and is applied to a full-duplex system with a close transceiving frequency interval. Signal receiving, filtering and processing scenes of a flexible load communication satellite are realized, the method can be used for receiving equipment of a ground communication system, the signal receiving and transmitting isolation capability of a full duplex system is improved, and the resistance to self interference and external interference is enhanced.

Description

Technical Field

[0001] This invention relates to a signal transmission and reception isolation and suppression processing system and method for a full-duplex system, belonging to the field of satellite receiving channel and ground communication equipment receiving technology design. Background Technology

[0002] With the rapid development of wireless communication technology and its applications, electromagnetic spectrum resources are becoming increasingly scarce, leading to a growing limitation on the frequencies allocated to wireless communication systems. This results in situations where the transmit and receive frequencies are close together in some radio frequency bands, causing significant problems for full-duplex systems operating simultaneously. To ensure normal system operation, signal transmission and reception isolation must meet certain constraints, such as ensuring that the power of the transmitted signal coupled to the receiving channel does not saturate the receiving channel, that the noise power of the transmitted signal coupled to the receiving channel is less than the noise floor of the received signal, and that passive intermodulation products generated by the shared transmit and receive system do not affect the signal-to-noise ratio of the receiving link.

[0003] Conventional methods such as antenna polarization isolation and high-order microwave cavity filtering cannot meet the needs of new application scenarios with close frequency spacing, high antenna gain, high requirements for transmit / receive isolation, compact spatial layout, and enhanced suppression of passive intermodulation products. Summary of the Invention

[0004] The technical problem solved by this invention is that conventional methods such as antenna polarization isolation and high-order microwave cavity filtering in the existing technology cannot meet the needs of new application scenarios. Therefore, a full-duplex system signal transmission and reception isolation suppression processing system and method are proposed.

[0005] The present invention solves the above-mentioned technical problem through the following technical solution:

[0006] A full-duplex system signal transmission and reception isolation and suppression processing system includes an antenna feed module, a transmission and reception filtering module, and a digital filtering module, wherein:

[0007] The antenna feed module receives the RF input signal, filters the transmit frequency band through antenna polarization isolation and microwave cavity filter to achieve initial suppression of transmission by reception, and sends the processed received signal to the transceiver filtering module; it receives the RF signal sent by the transceiver filtering module, filters and suppresses the receive frequency band, obtains the transmit frequency band signal and sends it outward;

[0008] The transceiver filtering module receives the RF signal after preliminary suppression processing sent by the antenna feed module, performs level adjustment, low-noise amplification and frequency conversion processing, and then obtains the intermediate frequency received signal and sends it to the digital filtering module; it receives the intermediate frequency signal to be transmitted from the digitally filtered signal, performs low-noise amplification and frequency conversion processing, and then sends the RF signal to the antenna feed module.

[0009] The digital filtering module performs power division processing on the intermediate frequency received signal sent by the transceiver filtering module. After power division, each signal is sequentially subjected to narrowband filtering, analog-to-digital conversion, digital filtering and switching processing, and digital-to-analog conversion. Finally, the output signals are combined to obtain one intermediate frequency signal to be transmitted and sent to the transceiver filtering module.

[0010] The antenna feed module includes a shared transmit / receive antenna, a microwave cavity receiving filter, and a microwave cavity transmitting filter, wherein:

[0011] The shared transmit and receive antenna is used for receiving radio frequency input signals and outputting transmit radio frequency band signals. It performs transmit and receive polarization isolation processing on the radio frequency input signal, filters the transmit radio frequency band signal, obtains the receive frequency band signal, and sends it to the microwave cavity receiving filter.

[0012] The microwave cavity receiving filter performs preliminary noise suppression processing on the received frequency band signal and sends it to the transceiver filtering module.

[0013] The microwave cavity transmitting filter receives the radio frequency signals sent by the transceiver filtering module, filters out the received frequency band signals, and then transmits them outwards through antenna transceiver polarization isolation processing.

[0014] The transceiver filtering module includes a receiving path and a transmitting path. The receiving path receives the RF signal after preliminary noise suppression processing sent by the antenna feed module, performs level adjustment, low-noise amplification, and frequency conversion processing, and then obtains the intermediate frequency (IF) received signal, which is sent to the digital filtering module. The transmitting path receives the IF signal to be transmitted from the digitally filtered signal, performs low-noise amplification and frequency conversion processing, and then sends the RF signal to the antenna feed module.

[0015] The receiving path includes a low-noise amplifier unit, a first-stage FBAR band-stop filter, a second-stage FBAR band-stop filter, and a downconverter. Low-noise amplifier units are installed before the first-stage FBAR band-stop filter, between the first-stage and second-stage FBAR band-stop filters, and after the second-stage FBAR band-stop filter. After the radio frequency signal enters the receiving path, it undergoes level adjustment through the first-stage FBAR band-stop filter, the second-stage FBAR band-stop filter, and the low-noise amplifier unit. The level-adjusted radio frequency signal is then amplified by the downconverter to generate an intermediate frequency (IF) receiving signal, which is then sent to the digital filtering module.

[0016] The transmitting path includes a low-noise amplifier, an isolator, a power amplifier, a first-stage FBAR band-stop filter, and an up-converter, wherein:

[0017] The low-noise amplifier and upconverter receive the intermediate frequency signal to be transmitted from the digitally filtered signal, convert it into a radio frequency signal, and then pass it through the first-stage FBAR band-stop filter and power amplifier for radio frequency signal amplification. After amplification, the radio frequency signal is sent to the antenna feed module after signal clutter suppression by the isolator set at the output of the transmit path.

[0018] The transmitting path and the corresponding receiving path form a set of narrowband sub-channels. Each set of narrowband sub-channels forms multiple narrowband sub-channels. The number of multiple narrowband sub-channels is not unique and is designed according to the signal parameters of the radio frequency signal or the intermediate frequency signal to be transmitted received by the transceiver filtering module.

[0019] The digital filtering module is equipped with a preset number of filter paths, combiners, and power dividers. The power divider receives the intermediate frequency received signal sent by the transceiver filtering module and performs power division processing. Each filter path sequentially performs narrowband filtering, analog-to-digital conversion, digital filtering and switching processing, and digital-to-analog conversion on each of the power-divided signals. Then, the combiner performs combining processing to obtain one intermediate frequency signal to be transmitted and sends it to the transceiver filtering module.

[0020] Each filter path is configured identically, and synchronous control is achieved through selection commands received from the gating switches of the digital filter module.

[0021] The filtering path includes an SPST switch, a SAW narrowband splitter filter, an analog-to-digital converter, an FPGA digital unit, a digital switching processing unit, and a digital-to-analog converter, wherein:

[0022] The SPST switch receives and selects the intermediate frequency received signal after power division processing. The selected signal is then sent to the SAW narrowband splitter filter for narrowband filtering. After narrowband filtering, the signal is converted from analog to digital by an analog-to-digital converter. The digital signal is then digitally filtered by the FPGA digital unit. After digital filtering, the signal is processed in the digital domain by the digital switching unit. After digital domain processing, the signal is converted from digital to analog by a digital-to-analog converter. The analog signals are then output to the combiner.

[0023] The selection instruction for the gating switch adopts RS422 instruction, which is converted into a TTL signal and then converted into a preset number of parallel control signals by the serial-to-parallel converter set in the digital filtering module. Each group of control signals selects or turns off one SPST switch respectively.

[0024] A processing method based on a full-duplex system signal transmission and reception isolation and suppression processing system includes:

[0025] The RF input signal is received by the shared antenna of the antenna feed module, and the transmit and receive polarization isolation processing and transmit frequency band filtering are performed to obtain the receive frequency band signal. After preliminary noise suppression processing, it is sent to the transmit and receive filtering module.

[0026] The transceiver filter module receives the radio frequency signal after preliminary noise suppression processing sent by the antenna feed module, performs level adjustment, low noise amplification and frequency conversion processing, and then obtains the intermediate frequency received signal and sends it to the digital filter module.

[0027] In the digital filtering module, the intermediate frequency received signal sent by the transceiver filtering module is processed by power division. After power division, each signal is sequentially processed by narrowband filtering, analog-to-digital conversion, digital filtering and switching, and digital-to-analog conversion. Then, each output signal is combined to obtain one intermediate frequency signal to be transmitted and sent to the transceiver filtering module.

[0028] The intermediate frequency signal to be transmitted is received by the transceiver filter module and then amplified and converted by low noise. The radio frequency signal is then sent to the antenna feed module.

[0029] The antenna feed module receives the radio frequency signal sent by the transceiver filtering module, performs transceiver polarization isolation processing and receive frequency band filtering, obtains the transmit frequency band signal, and sends it outward.

[0030] The transmit / receive polarization isolation process is used to distinguish between transmit frequency band signals and receive frequency band signals. The frequency bands corresponding to the transmit / receive polarization isolation process are different from those corresponding to the receive frequency band filtering and transmit frequency band filtering processes.

[0031] The advantages of this invention compared to the prior art are:

[0032] (1) The present invention provides a signal transmission and reception isolation suppression processing system and method for a full-duplex system. The signal transmission and reception isolation enhancement method applies antenna polarization isolation, microwave cavity bandpass filtering, multi-stage series FBAR bandstop filtering, multi-channel parallel SAW narrowband filtering, and split-channel digital filtering processing. It has high application value for full-duplex systems with close transmission and reception frequency intervals, especially satellite receiving channels. It can be applied to signal reception, filtering and processing scenarios of flexible payload communication satellites, and can also be used in ground communication system receiving equipment to improve the signal transmission and reception isolation capability of full-duplex systems, enhance resistance to self-interference and external interference, suppress background noise, improve signal-to-noise ratio, and ensure system communication quality.

[0033] (2) This invention improves the signal transmission and reception isolation capability of a full-duplex system. Initial isolation is achieved through antenna polarization isolation and high-order microwave cavity filtering. It also fully leverages the advantage of FBAR filters being integrated with microwave integrated circuits, and comprehensively applies multi-stage series FBAR band-stop filtering, multi-channel parallel SAW narrowband filtering, and branched digital filtering processing methods to effectively improve the signal-to-noise ratio of the received signal and ensure communication quality. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the full-duplex system signal transmission and reception isolation and suppression processing system provided by the present invention. Detailed Implementation

[0035] A signal transmission and reception isolation suppression processing system and method for full-duplex systems is disclosed. The system employs a signal transmission and reception isolation enhancement method using multi-stage cascaded FBAR band-stop filtering, multi-channel parallel SAW narrowband filtering, and split-channel digital filtering. It is applied to full-duplex systems with close transmission and reception frequency intervals to realize signal reception, filtering, and processing scenarios for flexible payload communication satellites. It can also be used in ground communication system receiving equipment to improve the signal transmission and reception isolation capability of full-duplex systems and enhance their resistance to self-interference and external interference.

[0036] The full-duplex system signal transmission and reception isolation and suppression processing system includes an antenna feed module, a transmission and reception filtering module, and a digital filtering module, wherein:

[0037] The antenna feed module receives the RF input signal, performs transmit / receive polarization isolation processing, acquires the received frequency band signal, performs preliminary noise suppression processing, and then sends it to the transmit / receive filter module; it receives the RF signal sent by the transmit / receive filter module, performs transmit / receive polarization isolation processing, acquires the transmit frequency band signal, and sends it outward;

[0038] The transceiver filtering module receives the RF signal after preliminary noise suppression processing sent by the antenna feed module, performs level adjustment, low-noise amplification and frequency conversion processing, and then obtains the intermediate frequency received signal and sends it to the digital filtering module; it also receives the intermediate frequency signal to be transmitted from the digitally filtered signal, performs low-noise amplification and frequency conversion processing, and then sends the RF signal to the antenna feed module.

[0039] The digital filtering module performs power division processing on the intermediate frequency received signal sent by the transceiver filtering module. After power division, each signal is sequentially subjected to narrowband filtering, analog-to-digital conversion, digital filtering and switching processing, and digital-to-analog conversion. Finally, the output signals are combined to obtain one intermediate frequency signal to be transmitted and sent to the transceiver filtering module.

[0040] The antenna feed module includes a shared transmit / receive antenna, a microwave cavity receiving filter, and a microwave cavity transmitting filter, wherein:

[0041] The shared transmit and receive antenna is used for receiving radio frequency input signals and outputting transmit radio frequency band signals. It performs transmit and receive polarization isolation processing on the radio frequency input signal, filters the transmit radio frequency band signal, obtains the receive frequency band signal, and sends it to the microwave cavity receiving filter.

[0042] The microwave cavity receiving filter performs preliminary noise suppression processing on the received frequency band signal and sends it to the transceiver filtering module.

[0043] The microwave cavity transmit filter receives the radio frequency signal sent by the transceiver filter module, filters out the received frequency band signal, and then transmits it outward through transceiver polarization isolation processing.

[0044] The transceiver filtering module includes a receiving path and a transmitting path. The receiving path receives the RF signal after preliminary noise suppression processing transmitted by the antenna feed module, performs level adjustment, low-noise amplification, and frequency conversion processing, and then obtains the intermediate frequency (IF) received signal, which is sent to the digital filtering module. The transmitting path receives the IF signal to be transmitted from the digitally filtered signal, performs low-noise amplification and frequency conversion processing, and then sends the RF signal to the antenna feed module. Wherein:

[0045] The receiving path includes a low-noise amplifier unit, a first-stage FBAR band-stop filter, a second-stage FBAR band-stop filter, and a downconverter. Low-noise amplifier units are installed before the first-stage FBAR band-stop filter, between the first-stage and second-stage FBAR band-stop filters, and after the second-stage FBAR band-stop filter. After the radio frequency signal enters the receiving path, it undergoes level adjustment through the first-stage FBAR band-stop filter, the second-stage FBAR band-stop filter, and the low-noise amplifier unit. The level-adjusted radio frequency signal is then amplified by the downconverter to generate an intermediate frequency (IF) receiving signal, which is then sent to the digital filtering module.

[0046] The transmitter path includes a low-noise amplifier, an isolator, a power amplifier, a first-stage FBAR band-stop filter, and an up-converter, wherein:

[0047] The low-noise amplifier and upconverter receive the intermediate frequency signal to be transmitted from the digitally filtered signal, convert it into a radio frequency signal, and then pass it through the first-stage FBAR band-stop filter and power amplifier for radio frequency signal amplification. After amplification, the radio frequency signal is sent to the antenna feed module after signal clutter suppression by the isolator set at the output of the transmit path.

[0048] The transmitting path and the corresponding receiving path form a set of narrowband sub-channels. Each set of narrowband sub-channels forms a multi-channel narrowband sub-channel. The number of channels in the multi-channel narrowband sub-channel is not unique and is designed according to the signal parameters of the radio frequency signal or the intermediate frequency signal to be transmitted received by the transceiver filtering module.

[0049] The digital filtering module is equipped with a preset number of filter paths, combiners, and power dividers. The power divider receives the intermediate frequency received signal sent by the transceiver filtering module and performs power division processing. Each filter path sequentially performs narrowband filtering, analog-to-digital conversion, digital filtering and switching processing, and digital-to-analog conversion on each of the power-divided signals. Then, the combiner performs combining processing to obtain one intermediate frequency signal to be transmitted and sends it to the transceiver filtering module.

[0050] Each filter path is configured identically, and synchronous control is achieved through selection commands received from the gating switches of the digital filter module.

[0051] The filtering path includes an SPST switch, a SAW narrowband splitter filter, an analog-to-digital converter, an FPGA digital unit, a digital switching processing unit, and a digital-to-analog converter, wherein:

[0052] The SPST switch receives and selects the intermediate frequency received signal after power division processing. The selected signal is then sent to the SAW narrowband splitter filter for narrowband filtering. After narrowband filtering, the signal is converted from analog to digital by an analog-to-digital converter. The digital signal is then digitally filtered by the FPGA digital unit. After digital filtering, the signal is processed in the digital domain by the digital switching unit. After digital domain processing, the signal is converted from digital to analog by a digital-to-analog converter. The analog signals are then output to the combiner.

[0053] The selection instruction for the strobe switch uses RS422 instructions, which are converted into TTL signals and then converted into a preset number of parallel control signals by the serial-to-parallel converter set in the digital filtering module. Each group of control signals selects or turns off one SPST switch.

[0054] The processing method implemented by the full-duplex system signal transmission and reception isolation suppression processing system can be summarized as follows: the RF input signal is received through the common antenna of the antenna feed module, the transmission and reception polarization isolation processing and the transmission frequency band filtering are performed to obtain the reception frequency band signal, and the signal is sent to the transmission and reception filtering module after preliminary noise suppression processing.

[0055] The transceiver filter module receives the radio frequency signal after preliminary noise suppression processing sent by the antenna feed module, performs level adjustment, low noise amplification and frequency conversion processing, and then obtains the intermediate frequency received signal and sends it to the digital filter module.

[0056] In the digital filtering module, the intermediate frequency received signal sent by the transceiver filtering module is processed by power division. After power division, each signal is sequentially processed by narrowband filtering, analog-to-digital conversion, digital filtering and switching, and digital-to-analog conversion. Then, each output signal is combined to obtain one intermediate frequency signal to be transmitted and sent to the transceiver filtering module.

[0057] The intermediate frequency signal to be transmitted is received by the transceiver filter module and then amplified and converted by low noise. The radio frequency signal is then sent to the antenna feed module.

[0058] The antenna feed module receives the radio frequency signal sent by the transceiver filtering module, performs transceiver polarization isolation processing and receive frequency band filtering, obtains the transmit frequency band signal, and sends it outward.

[0059] Transceiver polarization isolation is used to distinguish between transmit and receive frequency band signals. The frequency bands for transmit and receive polarization isolation are different from those for receive and transmit frequency band filtering.

[0060] The following description, in conjunction with the accompanying drawings and preferred embodiments, provides further details:

[0061] In the current embodiment, such as Figure 1 As shown, the full-duplex system signal transmission and reception isolation method is a signal transmission and reception isolation enhancement processing system that integrates microwave cavity bandpass filtering, multi-stage cascaded FBAR bandstop filtering, multi-channel parallel SAW narrowband filtering, and split-channel digital filtering. It comprises three parts: an antenna feed module, a transmission and reception filtering module, and a digital filtering module. The antenna feed module implements the transmission and reception functions of the full-duplex system wireless signal and achieves initial isolation of the transmitted and received signals through a compact microwave cavity filter. In the transmission and reception filtering module, a multi-stage (taking two stages as an example) cascaded FBAR bandstop filter is set on the receiving side, and a bandpass filter is set on the transmitting side to complete the further isolation and suppression of the transmitted and received signals, and to realize the conversion between radio frequency (RF) and intermediate frequency (IF) signals. In the digital filtering module, the input broadband signal is frequency-converted and then split. Multiple (taking three channels as an example) parallel SAW narrowband filters are used. Each narrowband signal undergoes analog-to-digital conversion, digital filtering, and digital-to-analog conversion, and then the signals are combined into a broadband output signal. After level adjustment and frequency conversion to the transmitting frequency band, digital filtering further enhances the suppression of signals outside the receiving channel.

[0062] The specific plan is as follows:

[0063] (1) The antenna feed module realizes the function of transmitting and receiving wireless signals in the full-duplex system.

[0064] A high-order microwave cavity receiver filter (such as a 10th-order Chebyshev filter) is installed in the receiving channel to allow the receiving frequency band signal to pass while filtering out the transmitting frequency band signal. A microwave cavity transmitter filter (such as a 5th-order Chebyshev filter) is installed in the transmitting channel to allow the transmitting frequency band signal to pass while filtering out the receiving frequency band signal (including noise spectrum generated by the transmitting link in the receiving frequency band, and active intermodulation interference generated by multi-frequency transmitted signals in the receiving frequency band). The microwave cavity transmitter filter needs to consider the high power capacity limitation of the transmitting channel. To improve product integration, the antenna feed, microwave cavity receiver filter, and microwave cavity transmitter filter can adopt a common integrated design. Initial isolation of the transmitting and receiving signals is achieved through antenna feed transmit / receive polarization isolation (e.g., 20dB), microwave cavity receiver filter (e.g., 70dB suppression of the transmitting frequency band), and microwave cavity transmitter filter (e.g., 60dB suppression of the receiving frequency band).

[0065] (2) The transceiver filtering module fully leverages the advantage of FBAR filters being integrated with microwave integrated circuits. By connecting FBAR bandstop filtering on the receiving side (taking 2 stages as an example) and bandpass filtering on the transmitting side, the transceiver signals are isolated and suppressed again, and the conversion between radio frequency signals and intermediate frequency signals is realized.

[0066] After passing through the microwave cavity receiving filter, the received signal enters the transceiver filtering module circuit with a multi-stage (taking two stages as an example) cascaded FBAR band-stop filter (such as the RSZK1500P060B1 chip). Each FBAR band-stop filter is preceded by a low-noise amplifier (LNA, such as the NC10229C-2640 chip) to adjust the level. Each FBAR band-stop filter provides 40dB suppression for the transmitting frequency band. The signal after passing through the FBAR band-stop filter then passes through a low-noise amplifier (such as the WFD008032-L18 chip) and a frequency converter (such as the BW351A chip) to convert the RF input signal to an intermediate frequency received signal, and then transmits it to the digital filtering module for digital domain processing.

[0067] On the other hand, the intermediate frequency (IF) signal to be transmitted from the digital filtering module is converted from IF to RF by a low-noise amplifier (such as the WFD008032-L18 chip) and a frequency converter (such as the BW351A chip). It then passes through another low-noise amplifier (such as the NC10229C-2640 chip) and an FBAR bandpass filter (such as the ACPF-7024 chip) to filter out signals outside the transmission frequency band. Finally, it is amplified by a power amplifier (such as the WFD008020-P30 chip). To ensure stable, reflection-free high-power signals, an isolator (such as the GD1679-1-J chip) is placed after the power amplifier. The RF signal is then sent to the microwave cavity transmit filter of the antenna feed module after passing through the isolator.

[0068] (3) The digital filtering module performs digital filtering and other processing on each narrowband signal by connecting multiple (taking 3 channels as an example) parallel SAW narrowband filters, thereby further enhancing the suppression of out-of-band signals.

[0069] The intermediate frequency (IF) received signal output from the transceiver filtering module enters the digital filtering module and is split into three channels (each channel has the same configuration) by a power divider (such as the NC6530C-0827 chip). Each channel is first selected by an SPST switch (such as the NC1644C-120 chip), then the passband of each channel is selected by a SAW narrowband splitter filter (such as the SMD3030C series chip), and then the analog signal is converted into a digital signal by an analog-to-digital converter (ADC, such as the B12D1600RH chip). Finally, digital filtering is performed by an FPGA (such as the JFM7K325T chip). This means further suppressing out-of-band signals in the digital domain. If the signal needs to be exchanged or processed in other digital domains, it can be performed using an FPGA (such as the JFM7K325T chip). Of course, this step is not necessary for enhanced suppression and is only used as an introduction to the completeness of the system design. The signal after digital domain processing is converted from digital to analog by a digital-to-analog converter (DAC, such as the GDA12SL3GMCB chip), and then the signals are combined into one signal to be transmitted by a combiner (such as the NC6530C-0827 chip) and output to the transmitting section of the transceiver filtering module.

[0070] If multiple channels need to be selected, a selection switch command (RS422 command) can be sent to the command converter of the digital filter module (such as the JS26C32 chip) to convert the RS422 command into a TTL signal. Then, the serial-to-parallel converter (such as the C45006RH chip) converts it into multiple sets (taking 3 sets as an example) of parallel control signals. Each set of control signals selects or disables one SPST selection switch. After each signal is processed by the SAW narrowband filter, digital domain filter, etc., they are combined to form a broadband intermediate frequency signal to be transmitted, which is then output to the transmitting section of the transceiver filter module.

[0071] (4) This invention fully leverages the advantages of FBAR filters and SAW filters being integrated with microwave integrated circuits. The full-duplex system signal transmission and reception isolation method presented is a signal transmission and reception isolation enhancement processing system that integrates microwave cavity bandpass filtering, multi-stage series FBAR bandstop filtering, multi-channel parallel SAW narrowband filtering, and branch digital filtering. All methods or several methods can be selected according to task requirements.

[0072] (5) Figure 1 As shown, a signal transmission and reception isolation and suppression method for a full-duplex system includes the following steps:

[0073] 1) The transmit and receive antennas share the same antenna to receive radio frequency (RF) input signals, and the receive frequency band signal is selected based on the transmit and receive polarization isolation of the antenna feed.

[0074] 2) The input signal is initially suppressed by the high-order microwave cavity receiving filter, which is designed to be integrated with the feed structure;

[0075] 3) The received signal enters the transceiver filtering module with a multi-stage (taking 2 stages as an example) cascaded FBAR band-stop filter. Each FBAR band-stop filter has a low-noise amplifier before it to adjust the level.

[0076] 4) The signal, after passing through multiple stages (taking 2 stages as an example) of cascaded FBAR band-stop filters, is then converted from radio frequency received signal to intermediate frequency received signal through a low-noise amplifier and frequency converter.

[0077] 5) After the intermediate frequency received signal enters the digital filtering module, it is divided into multiple parallel signals (taking 3 channels as an example) by the power divider. The configuration of each channel is the same. Here, only one channel is selected for description.

[0078] 6) Each signal is first selected by the SPST switch, and then the passband of each signal is selected by the SAW narrowband splitter filter;

[0079] 7) Each narrowband signal selected is converted from analog to digital by an analog-to-digital converter, and then digitally filtered by an FPGA to further suppress out-of-band signals in the digital domain;

[0080] 8) Depending on the system task requirements, if the signal needs to be exchanged or processed in other digital domains, other FPGAs can be used to perform the operation. Of course, this step is not necessary for enhancement and suppression, but is only used as an introduction to the completeness of the system design.

[0081] 9) The digitally processed signal is converted into an analog signal by a digital-to-analog converter, and then the signals are combined into a single intermediate frequency signal to be transmitted by a combiner.

[0082] 10) The intermediate frequency signal to be transmitted is sent to the low-noise amplifier and frequency converter in the transmitting section of the transceiver filter module to realize the conversion from intermediate frequency to radio frequency;

[0083] 11) Then, the signal passes through a low-noise amplifier and an FBAR bandpass filter to filter out signals outside the transmission frequency band, avoiding interference frequencies generated during processing and forwarding.

[0084] 12) Radio frequency power amplification is performed through a power amplifier. To ensure the stability and reflection-free operation of high-power signals, an isolator is installed after the power amplifier.

[0085] 13) The output signal after RF amplification enters the antenna feed module and passes through the microwave cavity transmit filter designed with the feed module as an integrated structure, allowing the transmit frequency band signal to pass through and filtering out the receive frequency band signal (including the noise spectrum formed by the transmit link in the receive frequency band, and the active intermodulation interference formed by the transmit multi-frequency signal in the receive frequency band, etc.).

[0086] 14) The filtered transmit signal enters the feed of the shared transmit / receive antenna for transmission;

[0087] 15) The above process describes the scenario where only one channel is selected to work in the multi-channel (taking 3 channels as an example) parallel SAW narrowband filtering of the digital filtering module. If it is necessary to select multiple channels to work, a selection switch instruction (RS422 instruction) can be sent to the digital filtering module, which is converted into a TTL signal by the instruction converter, and then converted into multiple sets (taking 3 sets as an example) of parallel control signals by the serial-to-parallel converter.

[0088] Each group of control signals selects or disables the SPST selector switch for each channel, and then steps 6) to 9) above are executed; the subsequent process of the combined intermediate frequency signal to be transmitted is the same as the above steps, and steps 10) to 14 above are executed.

[0089] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

[0090] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A full-duplex system signal transceiving isolation suppression processing system, characterized in that: it comprises an antenna feed module, a transceiving filter module and a digital filter module, wherein: the antenna feed module receives a radio frequency input signal, filters the transmission frequency band through antenna polarization isolation and a microwave cavity filter, realizes preliminary suppression of reception to transmission, and sends the obtained processed reception signal to the transceiving filter module; the transceiving filter module sends a radio frequency signal to the antenna feed module, filters and suppresses the reception frequency band, obtains the transmission frequency band signal, and sends it outward; the transceiving filter module receives the radio frequency signal sent by the antenna feed module after preliminary suppression processing, performs level adjustment, low noise amplification and frequency conversion processing, and sends the obtained intermediate frequency reception signal to the digital filter module; the transceiving filter module receives the to-be-transmitted intermediate frequency signal transmitted by the digital filter signal, performs low noise amplification and frequency conversion processing, and sends the radio frequency signal to the antenna feed module; the digital filter module performs power division processing on the intermediate frequency reception signal sent by the transceiving filter module, sequentially performs narrowband filtering, analog-to-digital conversion, digital filtering and switching processing, digital-to-analog conversion on each signal after power division processing, and performs combining processing on each output signal to obtain a to-be-transmitted intermediate frequency signal, and sends it to the transceiving filter module.

2. The full-duplex system signal transceiving isolation suppression processing system according to claim 1, characterized in that: the antenna feed module comprises a transceiving shared antenna, a microwave cavity reception filter and a microwave cavity transmission filter, wherein: the transceiving shared antenna is used for receiving a radio frequency input signal and outputting a transmission frequency band signal, performs transceiving polarization isolation processing on the radio frequency input signal, filters the transmission frequency band signal to obtain a reception frequency band signal, and sends it to the microwave cavity reception filter; the microwave cavity reception filter performs preliminary noise suppression processing on the reception frequency band signal and sends it to the transceiving filter module; the microwave cavity transmission filter receives the radio frequency signal sent by the transceiving filter module, filters out the reception frequency band signal, and sends it outward through antenna transceiving polarization isolation processing.

3. The full-duplex system signal transceiving isolation suppression processing system according to claim 1, characterized in that: the transceiving filter module comprises a receiving path and a transmission path, the receiving path receives the radio frequency signal sent by the antenna feed module after preliminary noise suppression processing, performs level adjustment, low noise amplification and frequency conversion processing, and sends the obtained intermediate frequency reception signal to the digital filter module, the transmission path receives the to-be-transmitted intermediate frequency signal transmitted by the digital filter signal, performs low noise amplification and frequency conversion processing, and sends the radio frequency signal to the antenna feed module, wherein: ​ ​ ​ ​ ​ ​ ​ ​ ​ The receiving path includes a low-noise amplifier unit, a first-stage FBAR band-stop filter, a second-stage FBAR band-stop filter, and a downconverter. Low-noise amplifier units are installed before the first-stage FBAR band-stop filter, between the first-stage and second-stage FBAR band-stop filters, and after the second-stage FBAR band-stop filter. After the radio frequency signal enters the receiving path, it undergoes level adjustment through the first-stage FBAR band-stop filter, the second-stage FBAR band-stop filter, and the low-noise amplifier unit. The level-adjusted radio frequency signal is then amplified by the downconverter to generate an intermediate frequency (IF) receiving signal, which is then sent to the digital filtering module.

4. The full-duplex system signal transmission and reception isolation and suppression processing system according to claim 3, characterized in that: The transmitting path includes a low-noise amplifier, an isolator, a power amplifier, a first-stage FBAR band-stop filter, and an up-converter, wherein: The low-noise amplifier and upconverter receive the intermediate frequency signal to be transmitted from the digitally filtered signal, convert it into a radio frequency signal, and then pass it through the first-stage FBAR band-stop filter and power amplifier for radio frequency signal amplification. After amplification, the radio frequency signal is sent to the antenna feed module after signal clutter suppression by the isolator set at the output of the transmit path.

5. The full-duplex system signal transmission and reception isolation and suppression processing system according to claim 4, characterized in that: The transmitting path and the corresponding receiving path form a set of narrowband sub-channels. Each set of narrowband sub-channels forms multiple narrowband sub-channels. The number of multiple narrowband sub-channels is not unique and is designed according to the signal parameters of the radio frequency signal or the intermediate frequency signal to be transmitted received by the transceiver filtering module.

6. The full-duplex system signal transmission and reception isolation and suppression processing system according to claim 4, characterized in that: The digital filtering module is equipped with a preset number of filter paths, combiners, and power dividers. The power divider receives the intermediate frequency received signal sent by the transceiver filtering module and performs power division processing. Each filter path sequentially performs narrowband filtering, analog-to-digital conversion, digital filtering and switching processing, and digital-to-analog conversion on each of the power-divided signals. Then, the combiner performs combining processing to obtain one intermediate frequency signal to be transmitted and sends it to the transceiver filtering module. Each filter path is configured identically, and synchronous control is achieved through selection commands received from the gating switches of the digital filter module.

7. The full-duplex system signal transmission and reception isolation and suppression processing system according to claim 6, characterized in that: The filtering path includes an SPST switch, a SAW narrowband splitter filter, an analog-to-digital converter, an FPGA digital unit, a digital switching processing unit, and a digital-to-analog converter, wherein: The SPST switch receives and selects the intermediate frequency received signal after power division processing. The selected signal is then sent to the SAW narrowband splitter filter for narrowband filtering. After narrowband filtering, the signal is converted from analog to digital by an analog-to-digital converter. The digital signal is then digitally filtered by the FPGA digital unit. After digital filtering, the signal is processed in the digital domain by the digital switching unit. After digital domain processing, the signal is converted from digital to analog by a digital-to-analog converter. The analog signals are then output to the combiner.

8. The full-duplex system signal transmission and reception isolation and suppression processing system according to claim 6, characterized in that: The selection instruction for the gating switch adopts RS422 instruction, which is converted into a TTL signal and then converted into a preset number of parallel control signals by the serial-to-parallel converter set in the digital filtering module. Each group of control signals selects or turns off one SPST switch respectively.

9. The processing method of claim 7, wherein the processing method is implemented by the full-duplex system signal transceiving isolation suppression processing system of claim 7. include: The RF input signal is received by the shared antenna of the antenna feed module, and the transmit and receive polarization isolation processing and transmit frequency band filtering are performed to obtain the receive frequency band signal. After preliminary noise suppression processing, it is sent to the transmit and receive filtering module. The transceiver filter module receives the radio frequency signal after preliminary noise suppression processing sent by the antenna feed module, performs level adjustment, low noise amplification and frequency conversion processing, and then obtains the intermediate frequency received signal and sends it to the digital filter module. In the digital filtering module, the intermediate frequency received signal sent by the transceiver filtering module is processed by power division. After power division, each signal is sequentially processed by narrowband filtering, analog-to-digital conversion, digital filtering and switching, and digital-to-analog conversion. Then, each output signal is combined to obtain one intermediate frequency signal to be transmitted and sent to the transceiver filtering module. The intermediate frequency signal to be transmitted is received by the transceiver filter module and then amplified and converted by low noise. The radio frequency signal is then sent to the antenna feed module. The antenna feed module receives the radio frequency signal sent by the transceiver filtering module, performs transceiver polarization isolation processing and receive frequency band filtering, obtains the transmit frequency band signal, and sends it outward.

10. The processing method according to claim 6, characterized in that: The transmit / receive polarization isolation process is used to distinguish between transmit frequency band signals and receive frequency band signals. The frequency bands corresponding to the transmit / receive polarization isolation process are different from those corresponding to the receive frequency band filtering and transmit frequency band filtering processes.

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