Dual-frequency common-aperture full-digital multi-beam phased-array antenna

Abstract

The invention relates to the field of phased-array antennas, in particular to a dual-frequency common-aperture full-digital multi-beam phased-array antenna, which comprises an active sub-array layer, an active network layer and a rear-end equipment layer which are connected in sequence, wherein the active sub-array layer comprises a plurality of modularized digital active sub-arrays; the active network layer is used for transmitting radio frequency, optical data and power supply between the active subarray layer and the back-end equipment layer; the rear-end equipment layer comprises a distributor, a digital beam forming and controlling device and a frequency source; according to the antenna system, modularized digital active sub-arrays serve as basic composition modules, and the single modularized digital active sub-array can achieve the functions of high-frequency-band radio-frequency signal emission, low-frequency-band radio-frequency signal receiving, radio-frequency signal frequency conversion and digitization, multi-beam processing at the same time of emission, multi-beam data output at the same time of receiving, internal monitoring signal receiving and transmitting, power conversion and the like.

Description

Technical Field

[0001] The present invention relates to the field of phased array antennas, and in particular to a dual-frequency co-aperture all-digital multi-beam phased array antenna. Background Art

[0002] The future satellite internet communications system will consist of numerous small satellite constellations and a global data service processing center. Targeted at the Internet of Things and mass satellite communications markets, it will offer diverse capabilities, including mobile communications and broadband internet access. This system will establish a globally open system of satellite internet standards, promote the internationalization of standards, enhance the voice of international cooperation, and orderly advance global satellite internet services. Targeting the core sectors of the national economy, it will build a high-quality, highly resilient, integrated space-ground satellite internet system to empower the development of vertical industries such as agriculture, industry, and modern services, as well as new sectors such as the low-altitude and marine economies, strengthening and expanding the digital economy. Furthermore, the system will be a pioneer in seizing space frequency and orbital resources, proactively addressing the expansion of foreign low-Earth orbits, and safeguarding national electromagnetic, cyber, and space security. The multi-beam phased array antenna payload is a core component of this system, enabling complex functions such as the transmission and reception of RF signals between satellites and ground terminals, frequency conversion, digital-to-analog / analog-to-digital conversion, and preprocessing.

[0003] Providing high-performance, high-quality satellite communication services to multiple users around the world requires higher requirements for the development of multi-beam phased array antenna systems due to their flexible configuration and efficient performance. Considering the requirements of satellite platforms and communication scenarios for antenna systems, multi-beam phased array antennas used in satellite Internet communication systems need to have the characteristics of flexible multi-beam, lightweight, high efficiency, and good economy. Summary of the Invention

[0004] The purpose of the present invention is to provide a dual-frequency common-port all-digital multi-beam phased array antenna. The antenna system adopts a "tile" type high-integration design architecture, and is composed of modular digital active sub-arrays, secondary power supplies, digital beam forming and control, frequency sources, calibration components, integrated networks, active mounting boards, etc. The levels of each single machine are clear and the interface is simple. The antenna adopts a modular design concept, and the modular digital active sub-arrays are independent in function and are the basic components of the antenna system. Different numbers of modular digital active sub-arrays can be spliced together to form antenna arrays of different apertures, thereby realizing the expansion of the antenna array aperture as needed. The antenna system adopts a unit-level digital array system, and each low-frequency radiating array element is connected to an independent receiver, and each high-frequency radiating array is connected to an independent transmitter. transmitter; the antenna system's transmission and reception both have digital multi-beam forming capabilities, and a two-level digital multi-beam synthesis architecture is adopted in the modular digital active sub-array and digital beamforming and control respectively, with distributed computing resources and low hardware requirements; the modular digital active sub-array adopts linear transmission and linear reception, which can meet the linearity requirements of current OFDM, 64QAM and other communication signals; the antenna system adopts a high and low dual-frequency nested common-port circularly polarized antenna array form, with high antenna aperture resource utilization; the modular digital active sub-array adopts a common board design, mainly including a dual-frequency circularly polarized nested radiating array, a digital transceiver board and other parts, and the digital transceiver board integrates power amplifiers, low-noise amplifiers, frequency converters, ADC / DAC, FPGA, electro-optical conversion, optoelectronic conversion and other parts.

[0005] The present invention provides the following technical solutions:

[0006] A dual-frequency co-port all-digital multi-beam phased array antenna, comprising an active sub-array layer, an active network layer, and a back-end equipment layer connected in sequence;

[0007] The active sub-array layer includes multiple modular digital active sub-arrays, each of which includes an FPGA and multiple receiving channels, multiple transmitting channels, and multiple radiating arrays. When sending data, the FPGA performs multi-beam formation on the beam IQ data received from the back-end device layer, sends it to the transmitting channel, and then radiates the signal through the radiating array. When receiving data, the microwave signal is received by the radiating array, sent to the receiving channel, and then enters the FPGA. After the FPGA performs multi-beam digital beam synthesis, the beam IQ data obtained is sent to the back-end device layer. The transmitting channel performs DAC, up-conversion, phase shifting, attenuation, and linear power amplifier on the input content in sequence; the receiving channel performs low-noise amplifier, phase shifting, attenuation, down-conversion, and ADC on the input content in sequence.

[0008] The active network layer is used to transmit radio frequency, optical data and power supply between the active sub-array layer and the back-end equipment layer;

[0009] The backend equipment layer includes a power distributor, digital beamforming and control, and a frequency source. The power distributor is used to provide power, the digital beamforming and control is used to send beam IQ data to the modular digital active sub-array, and receive beam IQ data from the modular digital active sub-array. The frequency source is used to provide the clock signal required by the module in the antenna.

[0010] Preferably, the process of performing transmit multi-beam forming in the FPGA is as follows: each digital transmit beam baseband data in the beam IQ data is multiplied by its corresponding transmit phase weight and then accumulated, and the accumulated baseband data is then subjected to peak clipping processing;

[0011] The process of multi-beam digital beamforming in the FPGA is as follows: the baseband data after the ADC of each receiving channel is multiplied by the beam weight corresponding to the channel, and then the baseband data of the same beam corresponding to all receiving channels of the building block digital active sub-array are accumulated to obtain the beam IQ data.

[0012] Preferably, the radiation array includes a radiation array module and a microwave feed board; the radiation array module is attached to the microwave feed board; the radiation array module includes a plurality of low-frequency radiation patches and a plurality of high-frequency radiation patches, and the plurality of low-frequency radiation patches and the plurality of high-frequency radiation patches respectively form right-handed and left-handed circularly polarized antennas with the microwave feed board;

[0013] Each low-frequency band radiation patch corresponds to a separate receiving channel, and each high-frequency band radiation patch corresponds to a separate transmitting channel.

[0014] Preferably, the active network layer further includes a calibration component, which is used to realize the coupled reception of the modular digital active sub-array transmission monitoring RF signal and complete the corresponding digital processing, output the amplitude and phase information of the corresponding transmission channel to the digital beamforming and control, and inject the modular digital active sub-array RF signal during reception monitoring.

[0015] Preferably, a structural active mounting plate is further included, wherein the active sub-array layer, the structural active mounting plate, and the active network layer are sequentially stacked and integrated in a "tile" style; the active sub-array layer is installed on the front side of the structural active mounting plate from the front, and the active network layer is installed on the back side of the structural active mounting plate from the rear; the active sub-array layer and the active network layer are interconnected through blind-plug interfaces, and openings are left at corresponding positions of the structural active mounting plate to avoid blind-plug interfaces between the active sub-array layer and the active network layer.

[0016] Beneficial effects:

[0017] 1. The antenna adopts a chip-type stacked integrated architecture. The antenna system is stacked from front to back in four parts: active sub-array layer, structural active mounting board, active network layer, and back-end equipment layer. Each layer is a "tile" design. After the entire antenna is integrated, the cross-section is thick and low.

[0018] 2. The antenna system is based on modular digital active subarrays as its basic module. A single modular digital active subarray can perform functions such as high-band RF signal transmission, low-band RF signal reception, RF signal frequency conversion and digitization, simultaneous multi-beam processing during transmission, simultaneous multi-beam data output during reception, internal monitoring signal transmission and reception, and power conversion. By horizontally splicing different numbers of modular digital active subarrays, different usage requirements can be met, offering flexible expansion and transforming complex antenna system debugging into subarray-centric debugging, making it suitable for large-scale mass production.

[0019] 3. The modular digital active sub-array adopts a chip-type integrated architecture, which integrates an 80-point radiating array module, 16-point low-frequency radiating patches, a 64-point high-frequency array, a microwave feed board, digital transceiver components and other parts. Each low-frequency radiating patch corresponds to a separate receiving digital channel, and each high-frequency radiating patch corresponds to a separate transmitting digital channel. By flexibly adjusting the transmitting and receiving digital channels, flexible transmission and reception of simultaneous digital multi-beams can be achieved.

[0020] 4. The antenna system adopts a multiplexing design. The high and low frequency radiation arrays adopt a dual-frequency nested circular polarization design. The transmitting and receiving digital channels adopt a mixed common board design of high and low frequency digital circuits and analog circuits. The clock and internal monitoring signals are transmitted through a set of RF networks in the shared active network layer, which improves the utilization efficiency of the entire antenna aperture and hardware utilization efficiency.

[0021] 5. The antenna system adopts a two-level digital beamforming architecture. For multi-beam reception, the modular digital active subarray multiplies the baseband data from the ADCs of different receive channels by different beam weights and accumulates them. This data is then output to the digital beamforming and control system at the back-end device layer for beam synthesis across the entire antenna. For multi-beam transmission, the modular digital active subarray multiplies the multiple transmit baseband beam data received from the digital beamforming and control system at the back-end device layer by the corresponding beam weights. This data is then accumulated, peak-clipped, and output to the DACs of the corresponding transmit channels. As can be seen from the above, the two-level digital beamforming architecture distributes multi-beam computing resources, resulting in high utilization of digital chips such as FPGAs and enhanced antenna system robustness.

[0022] 6. The antenna system can support high-frequency band transmission and low-frequency band reception at the same time. The high-frequency band radiation array and transmission link integration and the low-frequency band radiation array and reception link integration are completed inside the antenna respectively. Through the independent design of high-frequency band and low-frequency band RF links, the simultaneous transmission multi-beams and reception multi-beams formed by the antenna have little mutual influence, and the beam isolation can meet the use of frequency division duplex (FDD) satellite communication systems.

[0023] 7. The antenna system adopts a modular design. The active network layer and the back-end equipment layer are rationally divided into different single machines such as digital beam forming and control, frequency source, and secondary power supply according to their respective telecommunications functions, which is conducive to the lightweight integration, mass production and debugging of antennas. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the composition of the dual-frequency common-port all-digital multi-beam antenna of the present invention.

[0025] Figure 2 for Figure 1 Schematic diagram of the modular antenna aperture splicing of the medium-duplex common-port all-digital multi-beam antenna.

[0026] Figure 3 for Figure 1 Schematic diagram of the working principle of the medium-duplex frequency co-port all-digital multi-beam antenna.

[0027] Figure 4 for Figure 1 Schematic diagram of the modular digital active sub-array of the medium-duplex frequency co-port all-digital multi-beam antenna.

[0028] Figure 5 for Figure 1 Schematic diagram of the layered integration of modular digital active sub-arrays of the medium-duplex co-port all-digital multi-beam antenna.

[0029] Figure 6 for Figure 1 Schematic diagram of the modular digital active sub-array circularly polarized dual-band antenna of the medium-frequency co-port all-digital multi-beam antenna.

[0030] Figure 7 for Figure 1 Schematic diagram of the radiation array module of the medium-duplex frequency co-port all-digital multi-beam antenna.

[0031] Figure 8 for Figure 1 Active network layer topology diagram of the medium-duplex frequency co-port all-digital multi-beam antenna.

[0032] Figure 9 for Figure 1 Schematic diagram of the back-end equipment layout of the medium-duplex frequency co-port all-digital multi-beam antenna.

[0033] Figure 10 for Figure 1 Schematic diagram of the hierarchical formation of digital multi-beam transmission of the medium-duplex frequency co-port all-digital multi-beam antenna.

[0034] Figure 11 for Figure 1 Schematic diagram of the transmitting digital multi-beam single-channel data flow of the medium-frequency co-port all-digital multi-beam antenna.

[0035] Figure 12 for Figure 1 Schematic diagram of the receiving digital multi-beam hierarchical formation of the medium-duplex frequency common-port all-digital multi-beam antenna.

[0036] Figure 13 for Figure 1 Schematic diagram of the receiving digital multi-beam single-channel data flow of the medium-frequency co-port all-digital multi-beam antenna.

[0037] Figure 14 for Figure 1 The prototype of the dual-band common-port all-digital multi-beam antenna transmits the signal vector amplitude error (EVM) test results. The test center frequency is 3610 MHz and the signal bandwidth is 40 MHz.

[0038] Figure 15 for Figure 1 The ACLR test results of the prototype transmission signal of the medium-frequency common-port all-digital multi-beam antenna are shown. The test frequency is 3460MHz and the signal bandwidth is 40MHz.

[0039] Figure 16 for Figure 1 The prototype of the medium-frequency co-port all-digital multi-beam antenna transmits simultaneous multi-beam test results at a test frequency of 3460MHz.

[0040] Figure 17 for Figure 1 The prototype of the medium-frequency co-port all-digital multi-beam antenna receives simultaneous multi-beam test results, with the test frequency being 1970MHz.

[0041] Figure numerals: 1 active sub-array layer, 2 structural active mounting board, 3 active network layer, 4 back-end equipment layer, 11 modular active sub-array, 111 radiation array module, 112 microwave feeding board, 113 digital transceiver component front cover, 114 digital transceiver component, 115 digital transceiver component rear cover, 116 active sub-array interface, 111-1 "cross" low-frequency band radiation patch, 111-2 "circular" high-frequency band radiation patch, 116-1 power supply interface, 116-2 uplink and downlink optical interface, 116-3 multiplexing RF interface, 31 calibration component, 32 secondary power supply, 33 power supply cable, 34 optical power splitter and combiner, 35 optical signal distribution cable, 36 RF power splitter, 37 RF signal transmission cable, 41 digital beamforming and control, 42 frequency source, 43 antenna distributor, 44 secondary power supply in the cabin. DETAILED DESCRIPTION

[0042] In order to make the purposes, features, and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below 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 making creative work are within the scope of protection of the present invention.

[0043] like Figure 1 As shown, the dual-frequency common-surface all-digital multi-beam antenna of the present invention has an antenna system that is stacked from front to back in sequence, including four parts: an active sub-array layer 1, a structural active mounting plate 2, an active network layer 3, and a back-end equipment layer 4. The antenna system adopts a tile-type stacked integrated design, which has the advantages of thin thickness and light weight. The active sub-array layer 1 is installed on the front of the structural active mounting plate 2 from the front, and the active network layer 3 is installed on the back of the structural active mounting plate 2 from the back. The related equipment of the back-end equipment layer 4 can be installed in the satellite cabin, and signal interconnection with the active network layer 3 is achieved through optical cables, power cables, radio frequency circuits, etc. The active sub-array layer 1 and the active network layer 3 are both interconnected through blind plug interfaces. Openings are left at corresponding positions on the structural active mounting plate 2 to avoid blind plug interfaces between the active sub-array layer 1 and the active network layer 3.

[0044] like Figure 2 As shown, the active sub-array layer 1 is mainly composed of 26 modular digital active sub-arrays 11 horizontally spliced to form the antenna radiation aperture and meet the envelope constraint of the antenna aperture. The constructed antenna system includes 1664 transmit channels and 416 receive channels.

[0045] like Figure 3As shown, the modular digital active sub-array 11 mainly receives the beam IQ data sent by the digital beam forming and control 41 in the back-end equipment layer 4, and radiates to the specified airspace through the transmitting multi-beam forming, DAC, up-conversion, phase shifting, attenuation, linear power amplifier, and radiation array module 111 in the modular digital active sub-array 11. The microwave signal in the specified airspace is received and passes through the radiation array module 111, low-noise amplifier, phase shifting, attenuation, down-conversion, ADC, multi-beam digital beam synthesis, etc., and the beam IQ data is output to the digital beam forming and control 41. Each modular digital active sub-array 11 includes 16 low-band radiating patch units and 64 high-band radiating patch units. Each low-band radiating patch is connected to an independent receive channel, including an independent filter, low-noise amplifier, downconverter, and ADC. Each high-band radiating patch is connected to an independent transmit channel, including an independent filter, linear power amplifier, upper sideband, and DAC. Beam control for each sub-array and sub-array-level transmit and receive beamforming are implemented within the modular digital active sub-array 11 FPGA. Each modular digital active sub-array 11 is powered by a corresponding independent secondary power supply 32. The calibration component 31, through an internal monitoring network, couples and receives the modular digital active sub-array 11's transmit and monitor RF signals and performs the corresponding digital processing. It then outputs the amplitude and phase information of the corresponding transmit channel to the digital beamforming and control 41, as well as injects RF signals into the modular digital active sub-array 11 during receive monitoring. The frequency source 42 mainly completes the 100MHz reference clock of the receiving system and outputs three clock signals of 30.72MHz, 61.44MHz, and 307.2MHz required by various parts of the antenna system. It is distributed to 26 modular digital active sub-arrays 11, 1 calibration component 31, and 1 digital beamforming and control 41 and other equipment through the RF power splitter 36 and RF signal transmission cable 37 in the active network layer 3. The antenna distributor 43 receives external power-on or power-off OC control instructions to complete the power-on or power-off control of the secondary power supply 44 in the cabin. The secondary power supply 44 in the cabin is divided into four units, and every two units respectively power the digital beam forming and control 41 and the frequency source 42, and the two secondary power supplies 44 in the cabin supply power according to the main line, backup line and the main line and backup line in the digital beam forming and control 41 or the frequency source 42. The digital beam forming and control 41 completes the power-on and power-off control of the 26 secondary power supplies 32 in the active network layer 3 through CAN instructions. Each secondary power supply 32 completes the power supply of a corresponding modular digital active sub-array 11. The secondary power supply 32 at the installation position of the calibration component 31 needs to separate one line to power the calibration component 31 while completing the power supply to the corresponding modular digital active sub-array 11.The digital beamforming and control 41 receives the transmitted multi-beam baseband data input by the system. After processing and data synchronization by the digital beamforming and control 41, the transmitted multi-beam baseband data is distributed to the 26 modular digital active sub-arrays 11 through the optical power splitter and combiner 34 and the optical signal distribution cable 35 in the active network layer 3. At the same time, the multi-beam baseband data received by the 26 modular digital active sub-arrays 11 is fed into the digital beamforming and control 41 through the optical power splitter and combiner 34 and the optical signal distribution cable 35 in the active network layer 3 to perform simultaneous multi-beam synthesis at the reception level of the entire antenna system. The synthesized received multi-beam baseband data is output to the system baseband for subsequent processing.

[0046] like Figures 4 and 5 As shown, the modular digital active sub-array 11 adopts a "tile" stacked integrated architecture. From front to back, the modular digital active sub-array 11 consists of a radiation array module 111, a microwave feed board 112, a digital transceiver component front cover 113, a digital transceiver component 114, and a digital transceiver component rear cover 115. Each modular digital active sub-array 11 includes 16 digital receiving channels and 64 digital transmitting channels. The modular digital active sub-array 11 has 16 radiation array modules 111 on the front, which can realize the transmission and reception of low-frequency and high-frequency circularly polarized electromagnetic waves. The rear direction is the active sub-array interface 116, which can realize the transmission of radio frequency, optical data, power supply, etc. with the active network layer 3.

[0047] like Figures 6 and 7 As shown, the modular digital active sub-array 11 radiation array is mainly composed of 16 radiation array modules 111 and a microwave feed board 112. The 16 radiation array modules 111 are attached to the microwave feed board 112 to form a circularly polarized antenna array that can operate in both high and low frequency bands. The microwave feed board 112 is a multi-layer microwave board with a single layer of stripline inside. It can realize functions such as feeding the radiation array modules 111 and coupling the digital transceiver component 114 to transmit and receive signals. Each radiation array module 111 is injection molded, and a "cross" low-frequency band radiation patch 111-1 and four "circular" high-frequency band radiation patches 111-2 are attached to the surface. The "cross" low-frequency band radiation patch 111-1 and the "circular" high-frequency band radiation patch 111-2, respectively, form right-handed and left-handed circularly polarized antennas with their respective feeding structures.

[0048] like Figure 8As shown, the active network layer 3 primarily implements power supply, optical signal, and RF signal distribution between the active sub-array layer 1 and the back-end equipment layer 4. All components within the active network layer 3 are flatly mounted on the structural active mounting plate 2. The active network layer 3 primarily includes a calibration component 31, 26 secondary power supplies 32, a set of power supply cables 33, four optical power splitters and combiners 34, a set of optical signal distribution cables 35, five 1-to-4 RF power splitters 36, a set of RF signal transmission cables 37, and fourteen 1-to-2 RF power splitters 38. The calibration component 31 and the digital beamforming and control 41 in the back-end equipment layer 4 work together to achieve amplitude and phase calibration of all transmitting channels and receiving channels in the active sub-array layer 1; the power supply cable 33 distributes the power output by the antenna distributor 43 to the secondary power supply 32, and the secondary power supply 32 converts the power supply voltage and outputs it to the modular digital active sub-array 11. Each secondary power supply 32 corresponds to a modular digital active sub-array 11, and the secondary power supply 32 and the corresponding modular digital active sub-array 11 are interconnected through blind plugging; the optical power splitter and combiner 34 and the optical signal distribution cable 35 mainly complete the distribution and transmission of uplink and downlink digital optical signals between the digital beamforming and control 41 and the modular digital active sub-array 11 and the calibration component 31; the 1-to-4 RF power splitter 36, the 1-to-2 RF power splitter 38 and the RF signal transmission cable 37 complete the distribution and transmission of RF signals such as clock and internal monitoring between the calibration component 31, the modular digital active sub-array 11 and the frequency source 42.

[0049] like Figure 9 As shown, the digital beamforming and control 41 in the backend equipment layer 4 receives control signals and optical signals from external devices and generates control commands and control timing required by the antenna system. It also receives IQ data transmitted from the communication system baseband and distributes it to each modular digital active sub-array 11 in the active sub-array layer 1. It also receives digital beam IQ data output by each modular digital active sub-array 11 in the active sub-array layer 1 to perform digital beam synthesis and output the synthesized digital beam IQ data to the communication baseband. The frequency source 42 in the backend equipment layer 4 converts the reference clock provided by the satellite into clock signals of different frequencies required by the antenna system. The antenna power distributor 43 in the backend equipment layer 4 primarily distributes power signals input from the satellite platform to the active network layer 3 and receives control commands from the satellite platform to power up, down, and switch between active and standby modes for each unit in the antenna system. The in-cabin secondary power supply 44 in the backend equipment layer 4 converts the unregulated bus power provided by the satellite platform to meet the power requirements of the digital beamforming and control 41 and the frequency source 42.

[0050] like Figures 10 and 11As shown in the figure, the antenna system adopts two-stage digital multi-beam forming for transmission. The digital beamforming and control 41 receives 16 digital transmit beam baseband data output by the system baseband. The 16 digital transmit beam baseband data are distributed by the digital beamforming and control 41 to 26 modular digital active sub-arrays 11. Each digital transmit beam baseband data is multiplied by its corresponding transmit phase weight and then accumulated. The accumulated baseband data is converted into an analog signal through peak clipping and DAC.

[0051] like Figures 12 and 13 As shown in the figure, the antenna system adopts two-stage digital multi-beam forming for reception. In the modular digital active sub-array 11, the baseband data after ADC processing of each receiving channel is multiplied by the 16 beam weights corresponding to that channel. Then, the baseband data corresponding to the same beam of all receiving channels of the sub-array are accumulated to obtain the beam baseband data corresponding to the sub-array level. Following the same process as above, 16 simultaneously received baseband beam data at the sub-array level can be obtained. The 16 received baseband data of each modular digital active sub-array 11 are output to the digital beam forming and control 41. The digital beam forming and control 41 completes the accumulation of the beam data corresponding to 26 sub-arrays. In this way, the 16 receive beam baseband data of the entire antenna system are obtained and output to the system baseband for subsequent processing.

[0052] like Figures 14 to 17 As shown, the antenna system designed according to the above scheme can support the frequency division duplex (FDD) communication system. The transmit frequency band is 3440-3660 MHz, the receive frequency band is 1920-2025 MHz, the transmit frequency is left-hand circular polarization, and the receive frequency is right-hand circular polarization. The maximum beam scanning range of the transmit and receive antenna array is 51°, and the maximum signal bandwidth supported is 40 MHz. The spacing between the high-frequency band radiating elements is 40.5 mm, and the spacing between the low-frequency band radiating elements is 81 mm. The transmit channel adopts linear power amplification. The vector amplitude error, adjacent channel leakage ratio, and the number of transmit and receive beams of the entire antenna transmit beam all meet the requirements of the satellite communication system. The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A dual-frequency co-surface all-digital multi-beam phased array antenna, characterized in that: It includes the active sub-array layer, active network layer, and back-end equipment layer connected in sequence; The active sub-array layer includes multiple modular digital active sub-arrays, each of which includes an FPGA and multiple receiving channels, multiple transmitting channels, and multiple radiating arrays. When sending data, the FPGA performs multi-beam formation on the beam IQ data received from the back-end device layer, sends it to the transmitting channel, and then radiates the signal through the radiating array. When receiving data, the microwave signal is received by the radiating array, sent to the receiving channel, and then enters the FPGA. After the FPGA performs multi-beam digital beam synthesis, the beam IQ data obtained is sent to the back-end device layer. The transmitting channel performs DAC, up-conversion, phase shifting, attenuation, and linear power amplifier on the input content in sequence; the receiving channel performs low-noise amplifier, phase shifting, attenuation, down-conversion, and ADC on the input content in sequence. The active network layer is used to transmit radio frequency, optical data and power supply between the active sub-array layer and the back-end equipment layer; The backend equipment layer includes a power distributor, digital beamforming and control, and a frequency source. The power distributor is used to provide power, the digital beamforming and control is used to send beam IQ data to the modular digital active sub-array, and receive beam IQ data from the modular digital active sub-array. The frequency source is used to provide the clock signal required by the module in the antenna.

2. The dual-frequency co-plane all-digital multi-beam phased array antenna according to claim 1, characterized in that: The process of transmitting multi-beam forming in the FPGA is as follows: each digital transmit beam baseband data in the beam IQ data is multiplied by its corresponding transmit phase weight and then accumulated. The accumulated baseband data is then subjected to peak clipping processing. The process of multi-beam digital beamforming in the FPGA is as follows: the baseband data after the ADC of each receiving channel is multiplied by the beam weight corresponding to the channel, and then the baseband data of the same beam corresponding to all receiving channels of the building block digital active sub-array are accumulated to obtain the beam IQ data.

3. The dual-frequency co-plane all-digital multi-beam phased array antenna according to claim 1, characterized in that: The radiation array includes a radiation array module and a microwave feed board; the radiation array module is attached to the microwave feed board; the radiation array module includes a plurality of low-frequency radiation patches and a plurality of high-frequency radiation patches, and the plurality of low-frequency radiation patches and the plurality of high-frequency radiation patches respectively form right-handed and left-handed circularly polarized antennas with the microwave feed board; Each low-frequency band radiation patch corresponds to a separate receiving channel, and each high-frequency band radiation patch corresponds to a separate transmitting channel.

4. The dual-frequency co-plane all-digital multi-beam phased array antenna according to claim 1, characterized in that: The active network layer also includes a calibration component, which is used to realize the coupled reception of the modular digital active sub-array transmission monitoring RF signal and complete the corresponding digital processing, output the amplitude and phase information of the corresponding transmission channel to the digital beamforming and control, and inject the modular digital active sub-array RF signal during reception monitoring.

5. The dual-frequency co-port all-digital multi-beam phased array antenna according to claim 1, characterized in that: The invention also includes a structural active mounting plate, wherein the active sub-array layer, the structural active mounting plate, and the active network layer are sequentially stacked and integrated in a "tile" style; the active sub-array layer is mounted on the front of the structural active mounting plate from the front, and the active network layer is mounted on the back of the structural active mounting plate from the rear; the active sub-array layer and the active network layer are interconnected through blind-plug interfaces, and openings are left at corresponding positions on the structural active mounting plate to avoid blind-plug interfaces between the active sub-array layer and the active network layer.

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