A two-dimensional broadband active digital phased array

Abstract

This invention discloses a two-dimensional broadband active digital phased array. Under the control of a radar control unit, the subarray units process the transmitted and received electromagnetic signals and interact with a digital beamforming unit or a power divider / combiner network unit. The power divider / combiner network unit divides or combines signals from a monitoring and broadband transceiver integration unit or subarray units. The monitoring and broadband transceiver integration unit generates / receives monitoring signals, generates broadband excitation signals, and receives echoes. This solution employs a subarray-level analog and digital dual-link compensation design, integrating analog delay modules and digital modules at the subarray level, which are switched on demand via a switch group. It adopts a distributed broadband and centralized broadband integration design, adaptable to different application scenarios, with modular design and customizable features. It can be widely used in low-altitude surveillance radar, UAV detection systems, and other electronic equipment, providing high-performance detection solutions for low-altitude security, urban security, and broadband data acquisition.

Description

Technical Field

[0001] This invention belongs to the field of phased array radar, specifically relating to a two-dimensional broadband active digital phased array. Background Technology

[0002] With the rapid development of the low-altitude economy, scenarios such as drone logistics, urban air traffic, and low-altitude security have placed stringent demands on the high-precision, all-weather detection of low-altitude targets. In the low-altitude environment, targets are characterized by low altitude, slow speed, and small radar cross-section. Traditional phased array radars, limited by scanning methods and operating bandwidth, struggle to achieve high resolution while maintaining detection range, and their real-time tracking capability for multiple low-altitude targets is insufficient.

[0003] While phased array technology is widely used in existing low-altitude detection systems, significant bottlenecks remain in two-dimensional beam control, broadband signal processing, and active digital architecture.

[0004] a) Limitations of beam scanning: Traditional one-dimensional phased arrays can only achieve single-dimensional beam scanning (such as elevation angle), and azimuth angle adjustment relies on mechanical rotation, resulting in low scanning rate and difficulty in tracking high-speed maneuvering low-altitude targets.

[0005] b) Conflict between broadband signals and array: In order to improve distance resolution, broadband signals (such as bandwidth above 1 GHz) are introduced into phased array systems, but the aperture transit time problem of two-dimensional arrays is more prominent.

[0006] c) Performance bottlenecks of active channels: Existing phased arrays mostly use centralized RF front-ends, resulting in poor amplitude and phase consistency between channels. This leads to increased sidelobe levels in two-dimensional beams, making them susceptible to sidelobe clutter interference. For example, in low-altitude detection in complex terrain, ground clutter received by the sidelobes can significantly increase the false alarm rate of target detection.

[0007] In specific scenarios involving low-altitude detection, the above problems become particularly apparent:

[0008] a) Urban environment detection: The presence of tall buildings causes electromagnetic wave multipath reflection, and the high sidelobes of the beam will receive a large number of reflected signals, which reduces the signal-to-noise ratio of the target.

[0009] b) Low-altitude swarm target identification: When multiple UAVs fly densely, the range resolution of narrowband phased array is insufficient to distinguish individual targets.

[0010] c) Weak anti-interference capability: Low-altitude environments are filled with electromagnetic interference from numerous civilian electronic devices, and the fixed beams of traditional phased arrays cannot quickly avoid the direction of interference. For example, when suppressive interference is present, the target detection probability of existing systems will decrease significantly.

[0011] To address the aforementioned issues, two-dimensional broadband active digital phased arrays have become a key research focus, with their core advantages being:

[0012] a) Two-dimensional electronic scanning enables high-speed scanning within the coverage area, meeting the requirements for rapid low-altitude target tracking;

[0013] b) Wideband signals (1GHz~3GHz) improve distance resolution to within 0.5 meters, enabling the differentiation of dense targets;

[0014] c) The active channel design enables each array element to have independent transmit and receive capabilities, and achieves adaptive anti-interference through digital beamforming;

[0015] d) The processing architecture supports real-time two-dimensional beam optimization, improving target detection performance in complex environments.

[0016] However, existing two-dimensional broadband active digital phased arrays still face many challenges:

[0017] a) Aperture transit time compensation problem: The transmission delay of large bandwidth signals on the array aperture will cause beam pointing deviation.

[0018] b) High requirements for RF channel consistency: Amplitude and phase errors between multiple channels will degrade beamforming performance and make calibration difficult. Summary of the Invention

[0019] To address the aforementioned problems, the present invention aims to provide a two-dimensional broadband active digital phased array, namely a two-dimensional broadband active digital phased array with analog / digital dual-link compensation, distributed / centralized dual-detection links, and a multi-signal integrated calibration network, which is suitable for scenarios such as low-altitude detection, multi-target tracking, target imaging, and data acquisition.

[0020] The specific technical solution for achieving the objective of this invention is as follows:

[0021] A two-dimensional broadband active digital phased array includes subarray units, power divider and combining network units, monitoring and broadband transceiver integration units, radar control units, and digital beamforming units.

[0022] The subarray unit is used to process the transmitted and received electromagnetic wave signals and interact with the digital beamforming unit or power divider network unit under the control of the radar control unit.

[0023] The power divider and synthesizer network unit is used to divide or synthesize signals from the monitoring and broadband transceiver integration unit or subarray unit.

[0024] The monitoring and broadband transceiver integrated unit is used to realize the generation / reception of monitoring signals, the generation of broadband excitation signals, and the reception of echoes.

[0025] Furthermore, the subarray unit includes an antenna, a TR component, an analog delay module, a digital transceiver module, and an up / down conversion module;

[0026] The antenna is connected to the TR component to transmit and receive radio frequency signals. The TR component is connected to the up-conversion and down-conversion modules and is controlled by the digital transceiver module.

[0027] The up and down frequency conversion module is used to realize the signal frequency conversion between uplink and downlink, and integrates a switch group to realize the switching between distributed link and centralized link. The up and down frequency conversion module is connected to the analog delay module and the digital transceiver module, and is controlled by the digital transceiver module.

[0028] The analog delay module is used for real-time delay compensation, is connected to the power divider and combining network, and is controlled by the digital transceiver module.

[0029] The digital transceiver module is connected to the up-conversion and down-conversion modules via radio frequency (RF) connection. Control cables connect the TR component, up-conversion and down-conversion modules, and analog delay module. Optical fibers connect the radar control unit and digital beamforming unit. This module is used to parse radar control commands transmitted via uplink optical fiber, calculate and generate beam control codes, control the TR component, up-conversion and down-conversion modules, and analog delay module to operate according to corresponding parameters and timing, generate intermediate frequency (IF) signals, receive IF echo signals, perform analog-to-digital conversion, digital down-conversion, filtering, and packetization, and then transmit the signals downlink via optical fiber for subsequent processing.

[0030] Furthermore, the power divider combining network unit includes a first-level power divider combining network, a second-level power divider combining network, and a third-level power divider combining network;

[0031] The first-stage power divider and combining network is set between the antenna and the TR component of the subarray unit to realize signal combining and power dividing within the subarray unit.

[0032] The second-level power divider and the third-level power divider are sequentially arranged between the subarray unit and the monitoring and broadband transceiver integration unit;

[0033] The second-level power divider combining network is used to realize the power division combining of monitoring signals and broadband signals among multiple subarray units, as well as the power division of clock, local oscillator and dual local oscillator signals;

[0034] The third-level power divider and synthesizer network is used to complete centralized sum and difference beamforming and transmit excitation signal power division, and interacts with the clock signal and local oscillator signal.

[0035] Furthermore, when the switch group is switched to the connection delay module, the phased array operates in centralized broadband mode;

[0036] When the switch group is switched to connect to the frequency conversion channel in the upper and lower frequency conversion modules, the phased array operates in distributed narrowband mode, distributed broadband mode, transmit monitoring mode, or receive monitoring mode.

[0037] Furthermore, when the phased array operates in centralized broadband mode:

[0038] The clock signal is transmitted to the digital transceiver module in the subarray unit through the power divider and synthesizer network unit.

[0039] The local oscillator signal is transmitted to the monitoring and broadband transceiver integration unit;

[0040] The switch group in the up and down frequency conversion module switches to the delay module channel;

[0041] The digital transceiver module in the subarray unit determines the delay and phase shift values ​​based on the radar control unit and transmits them to the TR component, up / down conversion module and delay module;

[0042] If the phased array is in the transmitting state, the broadband transceiver component in the monitoring and broadband transceiver integration unit is set as the transmitting path. The broadband transceiver component generates an intermediate frequency signal, which is up-converted with the local oscillator signal to obtain a radio frequency excitation signal. After passing through the power divider and combining network unit, it is distributed and transmitted to the delay module of the subarray unit.

[0043] The delay module delays the excitation signal and outputs it to the digitally controlled delay channel in the up and down frequency conversion modules. Then, the power is divided and output to the TR component. The TR component outputs the excitation signal to the antenna for transmission after phase shifting and power amplification.

[0044] If the phased array is in receiving mode, the broadband transceiver component in the monitoring and broadband transceiver integration unit is set as the receiving path. The TR component transmits the RF echo signal received by the antenna to the delay channel of the up-conversion module. After attenuation, amplification, delay, and synthesis, the signal is transmitted to the delay module for simulated delay. Then, it is processed by the power divider and synthesizer network unit to form four analog beam RF signals: azimuth difference, elevation difference, and double difference, which are transmitted to the broadband transceiver component of the monitoring and broadband transceiver integration unit. The four analog beam RF signals are sampled, digitally down-converted, filtered, and decimated before being transmitted to the outside for further processing.

[0045] Furthermore, when the phased array operates in distributed narrowband mode:

[0046] The clock signal is transmitted to the digital transceiver module in the subarray unit through the power divider and synthesizer network unit.

[0047] The local oscillator signal is transmitted to the frequency converter module through a power divider and synthesizer network unit;

[0048] The switch group in the up and down frequency conversion modules is switched to the frequency conversion channel;

[0049] If the phased array is in transmit mode, the digital transceiver module in the subarray unit generates an intermediate frequency signal, which is then up-converted with the local oscillator signal and power divided to obtain multiple radio frequency excitation signals; these signals are then output to the TR component, which outputs the excitation signals to the antenna for transmission after phase shifting and power amplification.

[0050] If the phased array is in receiving mode, the TR component receives the radio frequency echo signal received by the antenna and modulates it with amplitude and phase to synthesize a radio frequency signal. The frequency conversion module performs analog synthesis, attenuation, and amplification on the radio frequency signal transmitted by the TR component, and obtains multiple intermediate frequency signals through two down-conversions. The digital transceiver module samples the intermediate frequency signal to obtain a digital signal, performs digital down-conversion, filtering, and decimation, and transmits the processed signal to the digital beamforming unit to form a digital beam, which is then transmitted to the outside for further processing.

[0051] Furthermore, when the phased array operates in distributed broadband mode:

[0052] The clock signal is transmitted to the digital transceiver module in the subarray unit through the power divider and synthesizer network unit.

[0053] The local oscillator signal is transmitted to the frequency converter module through a power divider and synthesizer network unit;

[0054] The switch group in the up and down frequency conversion modules is switched to the frequency conversion channel;

[0055] If the phased array is in transmit mode, the digital transceiver module in the subarray unit generates an intermediate frequency signal, which is then up-converted with the local oscillator signal and power divided to obtain multiple radio frequency excitation signals; these signals are then output to the TR component, which outputs the excitation signals to the antenna for transmission after phase shifting and power amplification.

[0056] If the phased array is in receiving mode, the TR component receives the radio frequency echo signal received by the antenna and modulates it with amplitude and phase to synthesize a single radio frequency signal. The frequency conversion module performs analog synthesis, attenuation, and amplification on the radio frequency signal transmitted by the TR component, and obtains multiple intermediate frequency signals after two down-conversions to achieve analog deskewing. The digital transceiver module samples the intermediate frequency signal to obtain a digital signal, performs digital down-conversion, filtering, and decimation, and transmits the processed signal to the digital beamforming unit to form a digital beam, which is then transmitted to the outside for further processing.

[0057] Furthermore, when the phased array is operating in transmit monitoring mode:

[0058] The phased array operates in a distributed narrowband mode, traversing each channel and each frequency point to transmit signals sequentially.

[0059] The transmitted radio frequency signal is coupled to the first-stage power divider network through a coupler integrated in the antenna, and then transmitted to the monitoring component in the monitoring and broadband transceiver integration unit through the second-stage and third-stage power divider networks in sequence.

[0060] The monitoring component operates in the receiving path, multiplexing the broadband transceiver component and the beam receiving channel to receive the radio frequency signal coupled to the monitoring, and then performing down-conversion, digital sampling, and digital processing in sequence.

[0061] The monitoring component receives and processes the digital signal, which is then transmitted to the subsequent processing module for analysis to obtain amplitude and phase information, which is used for phased array transmission amplitude and phase analysis and phase calibration.

[0062] Furthermore, when the phased array is operating in receive monitoring mode:

[0063] The phased array operates in a distributed narrowband mode, traversing each channel and frequency point to receive signals sequentially.

[0064] The monitoring component in the monitoring and broadband transceiver integration unit reuses the broadband transceiver component and beam transmission channel to generate radio frequency signals at controlled frequencies, and feeds them into the coupler integrated in the antenna through a power divider and combining network.

[0065] The coupler signal is fed into the receiving link in the distributed narrowband mode, and the array is controlled to open different receiving channels in sequence to receive signals and transmit them to the digital beamforming unit.

[0066] The digital beamforming unit performs amplitude and phase analysis to obtain the amplitude and phase of the full array receiving channel at multiple operating frequencies, which is used for the analysis and calibration of phased array receiving amplitude and phase.

[0067] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0068] (1) Analog and digital dual-link subarray compensation technology: This scheme adopts a subarray-level analog and digital dual-link compensation design, integrating an analog delay module (real-time delay compensation) and a digital module ("frequency shift and phase shift" + high-precision compensation) at the subarray level, which can be switched on demand through a switch group:

[0069] Analog link: It uses delay lines to quickly compensate for large-span delay differences and adopts an analog synthesis network and a centralized broadband receiver to receive echo signals;

[0070] Digital link: Echo reception is achieved through digital compensation algorithms ("frequency shifting and phase shifting"), distributed analog deskewing, distributed digital receivers, and DBF technology.

[0071] It features dual analog and digital link backup, can use simple linear frequency modulation descrambling signal form, and is also compatible with complex broadband waveform transmission and reception capabilities. It has strong anti-interference capabilities, can be customized and redundant, and can be used to develop various products.

[0072] Different methods can be selected to compensate for aperture transit time as needed, thereby improving distance resolution and anti-interference capability;

[0073] (2) Distributed and centralized dual-probe link technology: This solution adopts a distributed broadband and centralized broadband integrated design, which can be adapted to different application scenarios as needed, and is modularly designed and tailored as needed;

[0074] The distributed link features subarray-level digitization, flexible digital beamforming, high system anti-interference freedom, narrowband operation coverage for conventional search, and compatibility with broadband operation mode; the centralized link uses the second and third stage power divider combiners to centrally process multi-subarray signals (such as sum-difference synthesis), adapting to broadband anti-interference, high-precision tracking and other scenarios.

[0075] Both can be flexibly customized through modular design: the number of subarrays can be increased or decreased as needed (64 to 1536 channels), or the link working mode can be switched.

[0076] (3) Distributed multi-signal integrated calibration network technology: It can realize real-time amplitude and phase calibration of two-dimensional arrays and integrate multiple signals such as local oscillator, clock, and broadband. That is, the local oscillator signal, clock signal, broadband detection signal and amplitude and phase calibration signal are integrated in the three-level power divider synthesis network. Among them, the first-level power divider synthesis network adopts microstrip multilayer PCB design, which greatly reduces the use of cables, increases integration, and improves consistency and stability. The calibration signal is injected through the unit-level coupler to monitor the amplitude and phase error of the TR component and delay module in the subarray in real time (calibration period ≤ 1 second). The local oscillator, clock signal and broadband signal are transmitted in the same network, which reduces the number of cables and power dividers, simplifies the network topology, reduces network complexity and improves system stability.

[0077] From a performance perspective, this solution can achieve a radar detection range resolution of ≤0.2 meters, an angular resolution of ≤0.6°, and an anti-interference false alarm rate of ≤5%.

[0078] From the perspective of scenario adaptation, this solution supports multiple modes such as regular search, high-precision tracking, and broadband complex waveform anti-interference, and the hardware can be customized as needed.

[0079] The phased array calibration time of this solution is ≤1 second, the number of cables is reduced by 80%, and the system stability is improved by 40%. It is suitable for fixed, vehicle-mounted, shipborne and other platforms.

[0080] The solution of this invention can be widely applied to electronic devices such as low-altitude surveillance radar and UAV detection systems, providing high-performance detection solutions for fields such as low-altitude security, urban security, and broadband data acquisition;

[0081] The present invention will be further described below with reference to specific embodiments. Attached Figure Description

[0082] Figure 1 This is a schematic diagram of the system architecture of the two-dimensional broadband active digital phased array of the present invention.

[0083] Figure 2 This is a schematic diagram of the subarray unit architecture of the present invention.

[0084] Figure 3 This is a schematic diagram of the system operation link of the present invention.

[0085] Figure 4 This is a schematic diagram of the link of the phased array of the present invention in centralized broadband operating mode.

[0086] Figure 5 This is a schematic diagram of the broadband transceiver component of the present invention.

[0087] Figure 6 This is a schematic diagram of the link of the phased array of the present invention in distributed narrowband and distributed broadband operating modes.

[0088] Figure 7 This is a schematic diagram of the link of the phased array in the monitoring working mode of the present invention. Detailed Implementation

[0089] Example

[0090] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0091] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0092] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0093] Combination Figure 1 A two-dimensional broadband active digital phased array includes multiple subarray units, a power divider and combining network unit, a monitoring and broadband transceiver integration unit, a radar control unit, and a digital beamforming unit.

[0094] The subarray unit is used to process the transmitted and received electromagnetic wave signals and interact with the digital beamforming unit or power divider network unit under the control of the radar control unit.

[0095] The power divider and synthesizer network unit is used to divide or synthesize signals from the monitoring and broadband transceiver integration unit or subarray unit.

[0096] The monitoring and broadband transceiver integrated unit is used to realize the generation / reception of monitoring signals, the generation of broadband excitation signals, and the reception of echoes.

[0097] Combination Figure 2 The subarray unit includes an antenna, a TR component, an analog delay module, a digital transceiver module, and an up / down conversion module;

[0098] The antenna is directly connected to the TR component through the radio frequency feed line in the first layer network to realize the transmission and reception of radio frequency signals.

[0099] The TR component, or transmit / receive component, consists of 8 transmit and 8 receive channels, with circulators enabling transmit / receive switching. The main functions of the TR component are to amplify and output RF signals and amplify and receive echo signals. Additionally, each component contains 6-digit digitally controlled phase shifters for 8 transmit channels, and 6-digit digitally controlled phase shifters and 6-digit digitally controlled attenuators for 8 receive signals.

[0100] The TR component is connected to the antenna and the up-conversion / down-conversion modules in the integrated module via the RF feed line in the first layer network. In addition, the TR component is directly controlled by the FPGA in the digital transceiver module, and the secondary power supply supplies power to the TR component.

[0101] The up and down frequency conversion modules are used to realize the uplink and downlink signal frequency conversion, and integrate a switch group to realize the switching between distributed links and centralized links. The up and down frequency conversion modules are connected to the TR component through the feeder in the first layer network, and are connected to the analog delay module through RF cable inside the integrated module, and to the digital transceiver module through RF cable; and are connected to the secondary power supply through the power supply cable; the FGPA in the digital transceiver module controls the digitally controlled attenuator and switch in the up and down frequency conversion modules, and the secondary power supply supplies power to the up and down frequency conversion modules;

[0102] More specifically, the functions of the up and down frequency conversion modules in this embodiment include:

[0103] Function 1: The main function of the up and down frequency conversion module is to convert the uplink and downlink signal frequencies. The uplink converts the intermediate frequency signal (150MHz) into a radio frequency signal (14GHz~18GHz) through two frequency conversions. The maximum bandwidth of the narrowband intermediate frequency is 40MHz, and the maximum bandwidth of the wideband signal is 3GHz.

[0104] Function 2: In addition, the up and down frequency conversion modules also include STC (Time Sensitivity Control) function, which includes a digitally controlled attenuator with a maximum of 31dB and a step of 1dB.

[0105] Function 3: The up and down frequency conversion module integrates 4 channels of 3-wavelength digitally controlled delay units, which can be used for centralized broadband link real-time delay.

[0106] Function 4: It integrates a switch group to enable switching between distributed and centralized links.

[0107] The analog delay module is used to achieve real-time delay compensation in centralized broadband operating mode. The module contains a 5-digit digitally controlled analog delay unit with a maximum delay of 31 times the wavelength. The analog delay module is located inside the integrated module and is connected to the up and down frequency conversion components via RF cables; it is also connected to the digital transceiver and secondary power supply module via control cables to achieve control and power supply; and it is connected to the broadband transceiver module through the second-layer and third-layer power divider and combining network.

[0108] The digital transceiver module is connected to the up-conversion and down-conversion modules via radio frequency (RF) connection. Control cables connect the TR component, up-conversion and down-conversion modules, and analog delay module. Optical fibers connect the radar control unit and digital beamforming unit. This module is used to parse radar control commands transmitted via uplink optical fiber, calculate and generate beam control codes, control the TR component, up-conversion and down-conversion modules, and analog delay module to operate according to corresponding parameters and timing, generate intermediate frequency (IF) signals, receive IF echo signals, perform analog-to-digital conversion, digital down-conversion, filtering, and packetization, and then transmit the signals downlink via optical fiber for subsequent processing.

[0109] The power divider combining network unit includes a first-level power divider combining network, a second-level power divider combining network, and a third-level power divider combining network;

[0110] The first-stage power divider and combining network is set between the antenna and the TR component of the subarray unit to realize signal combining and power dividing within the subarray unit.

[0111] The second-level power divider and the third-level power divider are sequentially arranged between the subarray unit and the monitoring and broadband transceiver integration unit;

[0112] The second-level power divider combining network is used to realize the power division combining of monitoring signals and broadband signals among multiple subarray units, as well as the power division of clock, local oscillator and dual local oscillator signals;

[0113] The third-level power divider and synthesizer network is used to complete centralized sum and difference beamforming and transmit excitation signal power division, and interacts with the clock signal and local oscillator signal.

[0114] When the switch group is switched to the connection delay module, the phased array operates in centralized broadband mode;

[0115] When the switch group is switched to connect to the frequency conversion channel in the upper and lower frequency conversion modules, the phased array operates in distributed narrowband mode, distributed broadband mode, transmit monitoring mode, or receive monitoring mode.

[0116] Correspondingly, combined Figure 3 The system's operating links are divided into distributed narrowband operating links, distributed broadband operating links, and centralized broadband operating links; the system's monitoring links are divided into transmit monitoring links and receive monitoring links. When operating on the centralized broadband operating link, the switch group switches to the delay module. In the distributed narrowband, distributed broadband, transmit monitoring, and receive monitoring links, the system switches to the frequency conversion channel in the upconverter / downconverter module.

[0117] More specifically, combining Figure 4The centralized broadband link is one of the broadband working links in this system. The system uses analog descrambling technology to achieve the detection capability of linear frequency modulated signals with a maximum instantaneous bandwidth of 3GHz, and broadband direct sampling technology to achieve the detection capability of broadband complex waveforms with a maximum instantaneous bandwidth of 1GHz. It also has broadband detection and reception capabilities. The link connection relationship is different from that of the distributed narrowband working link. At this time, the switch group switches to the delay module.

[0118] When the phased array operates in centralized broadband mode:

[0119] The clock signal is transmitted to the digital transceiver module in the subarray unit through the power divider and synthesizer network unit. The digital transceiver module has the functions of controlling the delay module, TR component, and up and down frequency conversion module.

[0120] The local oscillator signal is transmitted to the monitoring and broadband transceiver integration unit;

[0121] The switch group in the up and down frequency conversion module switches to the delay module channel;

[0122] The one-channel and two-channel local oscillator signals are transmitted via cable to the broadband transceiver component of the monitoring and broadband transceiver integration unit. The broadband transceiver component has one transmit channel and four receive channels. Figure 5 As shown, it includes 1 channel for transmitting excitation generation (intermediate frequency signal generation, up-conversion, and power amplification) and 4 channels for echo reception (including low-noise amplification, down-conversion, and ADC).

[0123] The digital transceiver module in the subarray unit determines the delay value and phase shift value based on the radar control unit and transmits them to the TR component, up / down conversion module and delay module. In this embodiment, each TR component contains 8 transceiver phase shifters and 8 receiver attenuators, each up / down conversion module contains 4 three-wavelength delayers, and each delay module contains 4 three-wavelength delayers.

[0124] If the phased array is in the transmitting state, the broadband transceiver component in the monitoring and broadband transceiver integration unit is set as the transmitting path. The broadband transceiver component generates an intermediate frequency signal, which is up-converted with the local oscillator signal to obtain a radio frequency excitation signal. After passing through the power divider and combining network unit, it is distributed and transmitted to the delay module of the subarray unit.

[0125] The delay module delays the excitation signal and outputs it to the digitally controlled delay channel in the up and down frequency conversion modules. Then, the power is divided and output to the TR component. The TR component outputs the excitation signal to the antenna for transmission after phase shifting and power amplification.

[0126] Specifically, under the control of the radar control unit, the broadband transceiver component generates one intermediate frequency (IF) signal based on the DAC. Depending on the actual detection requirements, the IF signal can be a broadband signal (maximum 1 GHz) or a spot frequency. When the radar operating signal bandwidth is less than or equal to 1 GHz, the local oscillator is a spot frequency and the IF signal is a broadband signal. When the radar operating signal bandwidth is greater than 1 GHz, the local oscillator is a linear frequency modulated (LFM) signal (greater than 1 GHz) and the IF signal is a spot frequency.

[0127] One intermediate frequency signal is up-converted twice with two local oscillators and one local oscillator to obtain one radio frequency excitation signal, which is then distributed to the delay module of each subarray unit after passing through the power divider and combining network unit.

[0128] In the delay module, the excitation signal is transmitted to the up and down frequency converter components after a real-time delay;

[0129] In the up and down frequency converter components, the excitation signal is divided into 4 paths, and each of the 4 paths is further divided into 2 paths after delay control, resulting in 8 excitation signals. These are then sent to the eight-channel TR components. In each TR component, one excitation signal is divided into 8 excitation signals, which are then output after phase shifting and power amplification. Thus, the size of each subarray is 8×8.

[0130] If the phased array is in receiving mode, the broadband transceiver component in the monitoring and broadband transceiver integration unit is set as the receiving path. The TR component transmits the radio frequency echo signal received by the antenna to the delay channel of the up-conversion module. After attenuation, amplification, delay, and synthesis, the signal is transmitted to the delay module for simulated delay. It is then processed by the power divider and synthesizer network unit to form four analog beam radio frequency signals: azimuth difference, elevation difference, and double difference, which are transmitted to the broadband transceiver component of the monitoring and broadband transceiver integration unit. These four analog beam radio frequency signals are sampled, digitally down-converted, filtered, and decimated before being transmitted to the outside for further processing.

[0131] Specifically in this embodiment:

[0132] 1) Each eight-channel T / R module performs low-noise reception and amplitude-phase modulation on the RF echo signals received by the eight antenna elements to synthesize one RF signal;

[0133] 2) The up and down conversion modules simulate and synthesize the RF signals from every two T / R components into 4 RF signals, which are then combined into 1 RF echo signal after passing through a delay module and transmitted to the delay module.

[0134] 3) The delay module delays the echo signal before outputting it;

[0135] 4) The radio frequency echo signal of each subarray is processed by a power divider and synthesizer network to form four analog beam radio frequency signals: "sum, azimuth difference, elevation difference, and double difference".

[0136] 5) The broadband transceiver module samples the four RF signals to obtain digital signals (ADC), and performs digital down-conversion, filtering and decimation on the digital signals.

[0137] 6) The digital signal is transmitted to the subsequent processing module via the optical transmission network for algorithm processing.

[0138] The distributed narrowband link is the basic working link of this system, used for narrowband search and discovery. At this time, the switch group switches to the frequency conversion channel of the up and down frequency conversion modules. The narrowband link has two states: transmit and receive. A schematic diagram of the working link is shown below. Figure 6 As shown, when the phased array operates in distributed narrowband mode:

[0139] The clock signal is transmitted to the digital transceiver module in the subarray unit through the power divider and synthesizer network unit.

[0140] The local oscillator signal is transmitted to the frequency converter module through a power divider and synthesizer network unit;

[0141] The switch group in the up and down frequency conversion modules is switched to the frequency conversion channel;

[0142] That is, the clock signal is transmitted to the digital transceiver module in the subarray unit through the power divider and synthesizer network unit, and the number of digital transceiver channels is 4;

[0143] The local oscillator and local oscillator signals at the same frequency are transmitted to the frequency converter module through the power divider and synthesizer network unit. The frequency converter module has 4 channels.

[0144] If the phased array is in transmit mode, the digital transceiver module in the subarray unit generates an intermediate frequency signal, which is then up-converted with the local oscillator signal and power divided to obtain multiple radio frequency excitation signals; these signals are then output to the TR component, which outputs the excitation signals to the antenna for transmission after phase shifting and power amplification.

[0145] Specifically, in this embodiment, it includes:

[0146] 1) Under the control of the radar control unit, the digital transceiver components of each subarray generate four intermediate frequency signals based on the DAC;

[0147] 2) In the 4-channel frequency conversion of each subarray, the 4 intermediate frequency signals are converted into 8 radio frequency excitation signals after two up-conversions.

[0148] 3) The 8 RF excitation signals of each subarray are distributed into 8 excitation signals in 8 eight-channel T / R components and output after phase shifting and power amplification. The size of each subarray is 8×8.

[0149] If the phased array is in receiving mode, the TR component receives the radio frequency echo signal received by the antenna and modulates it with amplitude and phase to synthesize a radio frequency signal. The frequency conversion module performs analog synthesis, attenuation, and amplification on the radio frequency signal transmitted by the TR component, and obtains multiple intermediate frequency signals through two down-conversions. The digital transceiver module samples the intermediate frequency signal to obtain a digital signal, performs digital down-conversion, filtering, and decimation, and transmits the processed signal to the digital beamforming unit to form a digital beam, which is then transmitted to the outside for further processing.

[0150] Specifically, in this embodiment, it includes:

[0151] 1) Each eight-channel T / R module performs low-noise reception and amplitude-phase modulation on the echo signals received by the eight antenna elements to synthesize one radio frequency signal;

[0152] 2) The frequency conversion module simulates and synthesizes the radio frequency signals sent from every two T / R components, and then performs two down-conversions to obtain four intermediate frequency signals;

[0153] 3) The digital transceiver component samples the four analog intermediate frequency signals to obtain digital signals (ADC), and performs digital down-conversion, filtering and decimation on the digital signals.

[0154] 4) The digital signal is transmitted to the DBF via the optical transmission network to form a digital beam, and finally transmitted to the subsequent processing module for algorithm processing.

[0155] The distributed broadband link is one of the broadband working links in this system. The system achieves broadband transmission and reception synthesis through digital frequency and phase shifting and analog de-chirping processing. This not only realizes the broadband detection capability of instantaneous large bandwidth signals but also reduces the intermediate frequency bandwidth requirements of the transmitter and receiver, improving the system's cost-effectiveness. It can achieve broadband detection capability of linear frequency modulated signals with a maximum bandwidth of 3GHz. The link connection relationship is the same as that of the distributed narrowband working link, i.e., as follows... Figure 6 As shown, when the phased array operates in distributed broadband mode:

[0156] The clock signal is transmitted to the digital transceiver module in the subarray unit through the power divider and synthesizer network unit.

[0157] The local oscillator signal is transmitted to the frequency converter module through a power divider and synthesizer network unit;

[0158] The switch group in the upper and lower frequency converter modules is switched to the frequency converter channel;

[0159] That is, the clock signal is transmitted to the digital transceiver module in the subarray unit through the power divider and synthesizer network unit, and the number of digital transceiver channels is 4;

[0160] Broadband local oscillator and spot frequency local oscillator signals are transmitted to the frequency converter module through a power divider combining network unit. The frequency converter module has 4 channels.

[0161] If the phased array is in transmit mode, the digital transceiver module in the subarray unit generates an intermediate frequency signal, which is then up-converted with the local oscillator signal and power divided to obtain multiple radio frequency excitation signals; these signals are then output to the TR component, which outputs the excitation signals to the antenna for transmission after phase shifting and power amplification.

[0162] Specifically, in this embodiment, it includes:

[0163] 1) Under the control of the lightning control timing, the digital transceiver components of each subarray generate four frequency-shifted and phase-shifted intermediate frequency signals based on the DAC;

[0164] 2) In the 4-channel frequency conversion of each subarray, the 4 intermediate frequency signals are up-converted twice with the point frequency dual local oscillator and the linear frequency modulated broadband local oscillator, and the power is divided to obtain 8 RF excitation signals.

[0165] 3) The 8 RF excitation signals of each subarray are distributed into 8 excitation signals in 8 eight-channel T / R components and output after phase shifting and power amplification. The size of each subarray is 8×8.

[0166] If the phased array is in receiving mode, the TR component receives the radio frequency echo signal received by the antenna and modulates it with amplitude and phase to synthesize a single radio frequency signal. The frequency conversion module performs analog synthesis, attenuation, and amplification on the radio frequency signal transmitted by the TR component, and obtains multiple intermediate frequency signals after two down-conversions to achieve analog deskewing. The digital transceiver module samples the intermediate frequency signal to obtain a digital signal, performs digital down-conversion, filtering, and decimation, and transmits the processed signal to the digital beamforming unit to form a digital beam, which is then transmitted to the outside for further processing.

[0167] Specifically, in this embodiment, it includes:

[0168] 1) Each eight-channel T / R module performs low-noise reception and amplitude-phase modulation on the echo signals received by the eight antenna elements to synthesize one radio frequency signal;

[0169] 2) The frequency conversion module simulates and synthesizes the RF signals from each pair of T / R components, and then performs two down-conversions with the linear frequency modulated broadband local array and the point frequency dual local oscillator to obtain 4 intermediate frequency signals after simulated deskewing;

[0170] 3) The digital transceiver component samples the four analog intermediate frequency signals to obtain digital signals (ADC), and performs frequency shifting, phase shifting, digital down-conversion, filtering and decimation on the digital signals.

[0171] 4) The digital signal is transmitted to the DBF via the optical transmission network to form a digital beam, and finally transmitted to the subsequent processing module for algorithm processing.

[0172] The launch monitoring link is mainly used in the process of testing the phase and amplitude differences between each launch channel of the phased array, and is an important auxiliary link to ensure system performance.

[0173] The transmit monitoring link is based on a distributed narrowband link, with the addition of couplers, a monitoring feed network (integrated into the power divider / combiner network), and monitoring components. A schematic diagram of the link is shown below. Figure 7 As shown. The monitoring component and the broadband transceiver component share physical hardware; when the phased array operates in transmit monitoring mode:

[0174] The phased array operates in a distributed narrowband mode, traversing each channel and each frequency point to transmit signals sequentially.

[0175] The transmitted radio frequency signal is coupled to the first-stage power divider network through a coupler integrated in the antenna, and then transmitted to the monitoring component in the monitoring and broadband transceiver integration unit through the second-stage and third-stage power divider networks in sequence.

[0176] The monitoring component operates in the receiving path, multiplexing the broadband transceiver component and the beam receiving channel to receive the radio frequency signal coupled to the monitoring, and then performing down-conversion, digital sampling, and digital processing in sequence.

[0177] The monitoring component receives and processes the digital signal, which is then transmitted to the subsequent processing module for analysis to obtain amplitude and phase information, namely the amplitude and phase of the N transmission channels across the entire array at F operating frequencies, which is used for phased array transmission amplitude and phase analysis and phase calibration.

[0178] The receiver monitoring link is mainly used in the process of testing the phase and amplitude difference between each receiving channel of the phased array, and is an important auxiliary link to ensure system performance.

[0179] The receiving monitoring link is based on a distributed narrowband link, with the addition of a coupler, a monitoring feeder (integrated into the power divider / combiner network), and monitoring components. A schematic diagram of the link is shown below. Figure 6 As shown. The monitoring component and broadband transceiver component share physical hardware. Through rapid feedback correction via the receiving monitoring link, the beam main-to-side lobe ratio is guaranteed to be ≥25dB.

[0180] When the phased array is operating in receive monitoring mode:

[0181] The phased array operates in a distributed narrowband mode, traversing each channel and frequency point to receive signals sequentially.

[0182] The monitoring component in the monitoring and broadband transceiver integration unit reuses the broadband transceiver component and beam transmission channel to generate radio frequency signals at controlled frequencies, and feeds them into the coupler integrated in the antenna through a power divider and combining network.

[0183] The coupler signal is fed into the receiving link in the distributed narrowband mode, and the array is controlled to open different receiving channels in sequence to receive signals and transmit them to the digital beamforming unit.

[0184] The digital beamforming unit performs amplitude and phase analysis to obtain the amplitude and phase of the N receiving channels across the entire array at F operating frequencies, which is used for the analysis and calibration of the phased array receiving amplitude and phase.

[0185] This solution boasts superior performance, high adaptability to various scenarios, and promising engineering application prospects. It can be widely applied to electronic devices such as low-altitude surveillance radar and UAV detection systems, providing high-performance detection solutions for fields such as low-altitude security, urban security, and broadband data acquisition.

[0186] The embodiments described above are merely one implementation method of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A two-dimensional broadband active digital phased array, characterized in that, It includes subarray units, power divider and combining network units, monitoring and broadband transceiver integration units, radar control units, and digital beamforming units; The subarray unit is used to process the transmitted and received electromagnetic wave signals and interact with the digital beamforming unit or power divider network unit under the control of the radar control unit. The power divider and synthesizer network unit is used to divide or synthesize signals from the monitoring and broadband transceiver integration unit or subarray unit. The monitoring and broadband transceiver integrated unit is used to realize the generation / reception of monitoring signals, the generation of broadband excitation signals, and the reception of echoes. The subarray unit includes an antenna, a TR component, a delay module, a digital transceiver module, and a frequency up-conversion / down-conversion module; The antenna is connected to the TR component to transmit and receive radio frequency signals. The TR component is connected to the up-conversion and down-conversion modules and is controlled by the digital transceiver module. The up and down frequency conversion module is used to realize the signal frequency conversion between uplink and downlink, and integrates a switch group to realize the switching between distributed links and centralized links. The up and down frequency conversion module is connected to the delay module and the digital transceiver module, and is controlled by the digital transceiver module. The delay module is used for real-time delay compensation, is connected to the power divider and combining network, and is controlled by the digital transceiver module; The digital transceiver module is connected to the up-conversion and down-conversion modules via radio frequency (RF) connection. The control cable connects to the TR component, up-conversion and down-conversion modules, and delay module. The optical fiber connects to the radar control unit and the digital beamforming unit. It is used to parse the radar control commands transmitted from the uplink optical fiber, calculate and generate beam control codes, control the TR component, up-conversion and down-conversion modules, and delay module to work according to the corresponding parameters and timing, generate intermediate frequency (IF) signals, receive IF echo signals, perform analog-to-digital conversion, digital down-conversion, filtering, and packetization, and transmit the signals down to subsequent processing via optical fiber. When the switch group is switched to the connection delay module, the phased array operates in centralized broadband mode; When the switch group is switched to connect to the frequency conversion channel in the upper and lower frequency conversion modules, the phased array operates in distributed narrowband mode, distributed broadband mode, transmit monitoring mode, or receive monitoring mode.

2. The two-dimensional broadband active digital phased array according to claim 1, characterized in that, The power divider combining network unit includes a first-level power divider combining network, a second-level power divider combining network, and a third-level power divider combining network; The first-stage power divider and combining network is set between the antenna and the TR component of the subarray unit to realize signal combining and power dividing within the subarray unit. The second-level power divider and the third-level power divider are sequentially arranged between the subarray unit and the monitoring and broadband transceiver integration unit; The second-level power divider combining network is used to realize the power division combining of monitoring signals and broadband signals among multiple subarray units, as well as the power division of clock, local oscillator and dual local oscillator signals; The third-level power divider and synthesizer network is used to complete centralized sum and difference beamforming and transmit excitation signal power division, and interacts with the clock signal and local oscillator signal.

3. The two-dimensional broadband active digital phased array according to claim 2, characterized in that, When the phased array operates in centralized broadband mode: The clock signal is transmitted to the digital transceiver module in the subarray unit through the power divider and synthesizer network unit. The local oscillator signal is transmitted to the monitoring and broadband transceiver integration unit; The switch group in the up and down frequency conversion module switches to the delay module channel; The digital transceiver module in the subarray unit determines the delay and phase shift values ​​based on the radar control unit and transmits them to the TR component, up / down conversion module and delay module; If the phased array is in the transmitting state, the broadband transceiver component in the monitoring and broadband transceiver integration unit is set as the transmitting path. The broadband transceiver component generates an intermediate frequency signal, which is up-converted with the local oscillator signal to obtain a radio frequency excitation signal. After passing through the power divider and combining network unit, it is distributed and transmitted to the delay module of the subarray unit. The delay module delays the excitation signal and outputs it to the digitally controlled delay channel in the up and down frequency conversion modules. Then, the power is divided and output to the TR component. The TR component outputs the excitation signal to the antenna for transmission after phase shifting and power amplification. If the phased array is in receiving mode, the broadband transceiver component in the monitoring and broadband transceiver integration unit is set as the receiving path. The TR component transmits the RF echo signal received by the antenna to the delay channel of the up-conversion module. After attenuation, amplification, delay, and synthesis, the signal is transmitted to the delay module for simulated delay. Then, it is processed by the power divider and synthesizer network unit to form four analog beam RF signals: azimuth difference, elevation difference, and double difference, which are transmitted to the broadband transceiver component of the monitoring and broadband transceiver integration unit. The four analog beam RF signals are sampled, digitally down-converted, filtered, and decimated before being transmitted to the outside for further processing.

4. The two-dimensional broadband active digital phased array according to claim 2, characterized in that, When the phased array operates in distributed narrowband mode: The clock signal is transmitted to the digital transceiver module in the subarray unit through the power divider and synthesizer network unit. The local oscillator signal is transmitted to the frequency converter module through a power divider and synthesizer network unit; The switch group in the up and down frequency conversion modules is switched to the frequency conversion channel; If the phased array is in transmit mode, the digital transceiver module in the subarray unit generates an intermediate frequency signal, which is then up-converted with the local oscillator signal and power divided to obtain multiple radio frequency excitation signals; these signals are then output to the TR component, which outputs the excitation signals to the antenna for transmission after phase shifting and power amplification. If the phased array is in receiving mode, the TR component receives the radio frequency echo signal received by the antenna and modulates it with amplitude and phase to synthesize a radio frequency signal. The frequency conversion module performs analog synthesis, attenuation, and amplification on the radio frequency signal transmitted by the TR component, and obtains multiple intermediate frequency signals through two down-conversions. The digital transceiver module samples the intermediate frequency signal to obtain a digital signal, performs digital down-conversion, filtering, and decimation, and transmits the processed signal to the digital beamforming unit to form a digital beam, which is then transmitted to the outside for further processing.

5. The two-dimensional broadband active digital phased array according to claim 2, characterized in that, When the phased array operates in distributed broadband mode: The clock signal is transmitted to the digital transceiver module in the subarray unit through the power divider and synthesizer network unit. The local oscillator signal is transmitted to the frequency converter module through a power divider and synthesizer network unit; The switch group in the up and down frequency conversion modules is switched to the frequency conversion channel; If the phased array is in the transmit state, the digital transceiver module in the subarray unit generates an intermediate frequency signal, which is then up-converted with the local oscillator signal and divided by a power divider to obtain multiple radio frequency excitation signals. The signal is output to the TR component, which then performs phase shifting and power amplification before outputting it to the antenna for transmission. If the phased array is in receiving mode, the TR component receives the radio frequency echo signal received by the antenna and modulates it with amplitude and phase to synthesize a single radio frequency signal. The frequency conversion module performs analog synthesis, attenuation, and amplification on the radio frequency signal transmitted by the TR component, and obtains multiple intermediate frequency signals after two down-conversions to achieve analog deskewing. The digital transceiver module samples the intermediate frequency signal to obtain a digital signal, performs digital down-conversion, filtering, and decimation, and transmits the processed signal to the digital beamforming unit to form a digital beam, which is then transmitted to the outside for further processing.

6. The two-dimensional broadband active digital phased array according to claim 3, characterized in that, When the phased array is operating in transmit monitoring mode: The phased array operates in a distributed narrowband mode, traversing each channel and each frequency point to transmit signals sequentially. The transmitted radio frequency signal is coupled to the first-stage power divider network through a coupler integrated in the antenna, and then transmitted to the monitoring component in the monitoring and broadband transceiver integration unit through the second-stage and third-stage power divider networks in sequence. The monitoring component operates in the receiving path, multiplexing the broadband transceiver component and the beam receiving channel to receive the radio frequency signal coupled to the monitoring, and then performing down-conversion, digital sampling, and digital processing in sequence. The monitoring component receives and processes the digital signal, which is then transmitted to the subsequent processing module for analysis to obtain amplitude and phase information, which is used for phased array transmission amplitude and phase analysis and phase calibration.

7. The two-dimensional broadband active digital phased array according to claim 1, characterized in that, When the phased array is operating in receive monitoring mode: The phased array operates in a distributed narrowband mode, traversing each channel and frequency point to receive signals sequentially. The monitoring component in the monitoring and broadband transceiver integration unit reuses the broadband transceiver component and beam transmission channel to generate radio frequency signals at controlled frequencies, and feeds them into the coupler integrated in the antenna through a power divider and combining network. The coupler signal is fed into the receiving link in the distributed narrowband mode, and the array is controlled to open different receiving channels in sequence to receive signals and transmit them to the digital beamforming unit. The digital beamforming unit performs amplitude and phase analysis to obtain the amplitude and phase of the full array receiving channel at multiple operating frequencies, which is used for the analysis and calibration of phased array receiving amplitude and phase.

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