Two-dimensional broadband active digital phased array

Abstract

The invention discloses a two-dimensional broadband active digital phased array, which is characterized in that a sub-array unit processes received and transmitted electromagnetic wave signals under the control of a radar control unit and interacts with a digital beam forming unit or a power division and synthesis network unit; the power division and synthesis network unit carries out power division or synthesis on signals from the monitoring and broadband transceiving integrated unit or the sub-array unit, and the monitoring and broadband transceiving integrated unit realizes monitoring signal generation / reception, broadband excitation signal generation and echo reception. According to the scheme, a sub-array level analog and digital double-link compensation design is adopted, an analog delay module and a digital module are integrated at a sub-array level, and switching is carried out as required through a switch group; a distributed broadband and centralized broadband integrated design is adopted, different application scenes can be adapted according to needs, modular design is adopted, and tailoring is carried out according to needs; the device can be widely applied to electronic equipment such as low-altitude monitoring radars and unmanned aerial vehicle detection systems, and a high-performance detection solution is provided for the fields of low-altitude safety, urban security and protection, broadband data acquisition and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of phased array radars, and particularly relates to a two-dimensional wideband active digital phased array. BACKGROUND

[0002] With the rapid development of low-altitude economy, unmanned aerial vehicle logistics, urban air traffic, low-altitude security and other scenarios have put forward strict requirements for high-precision and all-weather detection of low-altitude targets. In the low-altitude environment, the target has the characteristics of low, slow and small (low altitude, slow speed and small radar cross section). The traditional phased array radar is limited by the scanning mode and the working bandwidth, and it is difficult to realize high resolution while ensuring detection distance, and the real-time tracking ability of multiple low-altitude targets is insufficient.

[0003] In the existing low-altitude detection system, phased array technology has been widely used, but there are significant bottlenecks in two-dimensional beam control, wideband signal processing and active digital architecture:

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

[0005] b) Wideband signal and array contradiction: To improve the range resolution, wideband signals (such as bandwidth above 1GHz) are introduced into the phased array system, but the aperture transit time problem of two-dimensional arrays is more prominent.

[0006] c) Active channel performance bottleneck: Existing phased arrays mostly use centralized RF front-ends, and the amplitude and phase consistency between channels is poor, resulting in high two-dimensional beam sidelobe level and susceptibility to sidelobe clutter interference. For example, in complex terrain low-altitude detection, the ground clutter received by the sidelobe will greatly increase the target detection false alarm rate.

[0007] In the specific scenarios of low-altitude detection, the above problems are particularly evident:

[0008] a) Urban environment detection: The high-rise buildings cause electromagnetic wave multipath reflection, and the high sidelobe of the beam will receive a large amount of reflected signals, reducing the signal-to-noise ratio of the target.

[0009] b) Low-altitude cluster target identification: When multiple unmanned aerial vehicles fly in close formation, the narrowband phased array has insufficient range resolution to distinguish individual targets.

[0010] c) Weak anti-interference ability: There are a large number of electromagnetic interference from civil electronic devices in the low-altitude environment, and the fixed beam of the traditional phased array cannot quickly avoid the interference direction. For example, when there is suppressive jamming, the target detection probability of the existing system will decrease significantly.

[0011] To solve the above problems, two-dimensional wideband active digital phased array has become a research focus, and its core advantages are:

[0012] a) Two-dimensional electric scanning realizes high-speed scanning in coverage area, meeting low-altitude fast target tracking requirements;

[0013] b) Wideband signal (1GHz-3GHz) improves range resolution to within 0.5 meters, and can distinguish dense targets;

[0014] c) Active channel design enables each array element to have independent transmitting and receiving capabilities, and adaptive anti-interference is realized through digital beam forming;

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

[0016] However, the existing two-dimensional wideband active digital phased array still faces many challenges:

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

[0018] b) High consistency requirement of radio frequency channel: amplitude and phase errors between multiple channels will worsen the beam forming performance, making calibration difficult. SUMMARY

[0019] To solve the above problems, the purpose of the present application is to provide a two-dimensional wideband active digital phased array, which is a two-dimensional wideband active digital phased array with analog / digital dual-link compensation, distributed / centralized dual-probe link and multi-signal integrated calibration network, suitable for low-altitude detection, multi-target tracking, target imaging, data acquisition and other scenes.

[0020] The specific technical solution to achieve the purpose of the present application is:

[0021] A two-dimensional wideband active digital phased array, comprising a subarray unit, a power division and synthesis network unit, a monitoring and wideband transceiver integrated unit, a radar control unit and a digital beam synthesis unit;

[0022] The subarray unit is used to interact with the digital beam synthesis unit or the power division and synthesis network unit under the control of the radar control unit after processing the received electromagnetic wave signals;

[0023] The power division and synthesis network unit is used to divide or synthesize signals from the monitoring and wideband transceiver integrated unit or the subarray unit;

[0024] The monitoring and wideband transceiver integrated unit is used to realize monitoring signal generation / reception, wideband excitation signal generation and echo reception.

[0025] Further, 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 and the TR component are connected to realize the transmission and reception of radio frequency signals, the TR component and the up-down conversion module are connected, and the up-down conversion module is controlled by the digital transceiver module;

[0027] The up-down conversion module is used to realize the frequency conversion of uplink and downlink signals, and integrates a switch group to realize the switching of distributed links and centralized links, the up-down conversion module is connected with 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, and is connected with the power division and synthesis network and is controlled by the digital transceiver module;

[0029] The digital transceiver module is connected with the up-down conversion module in radio frequency, the control cable is connected with the TR component, the up-down conversion module and the analog delay module, the optical fiber is connected with the radar control unit and the digital beam synthesis unit, and is used to parse the radar control instruction transmitted by the uplink optical fiber, calculate and generate the beam control code, control the TR component, the up-down conversion module and the analog delay module to work according to the corresponding parameters and time sequence, and generate intermediate frequency signals, receive intermediate frequency echo signals, do analog-digital conversion, digital down conversion, filtering and packaging, and then transmit to the subsequent processing through the optical fiber.

[0030] Further, the power division and synthesis network unit includes a first-stage power division and synthesis network, a second-stage power division and synthesis network and a third-stage power division and synthesis network;

[0031] The first-stage power division and synthesis network is arranged between the antenna and the TR component of the subarray unit, and is used to realize the signal synthesis and power division in the subarray unit;

[0032] The second-stage power division and synthesis network and the third-stage power division and synthesis network are arranged between the subarray unit and the monitoring and wideband transceiver integrated unit in sequence;

[0033] The second-stage power division and synthesis network is used to realize the power division and synthesis of monitoring signals and wideband signals between multiple subarray units, and the power division of clock signals, one local oscillator signal and two local oscillator signals;

[0034] The third-stage power division and synthesis network is used to complete the centralized and difference beam synthesis and transmit excitation signal power division, and realizes the interaction with the clock signal and the local oscillator signal.

[0035] Further, when the switch group is switched to connect the delay module, the phased array works in a centralized wideband mode;

[0036] When the switch group is switched to connect the up-down conversion module in the frequency conversion channel, the phased array works in a distributed narrowband mode, a distributed wideband mode, a transmit monitoring mode or a receive monitoring mode.

[0037] Further, when the phased array works in the centralized broadband mode:

[0038] The clock signal is transmitted to the digital transceiver module in the subarray unit through the power division and synthesis network unit;

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

[0040] The switch group in the up-down conversion module is switched to the delay module channel;

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

[0042] If the phased array is in the transmitting state, the broadband transceiver component in the monitoring and broadband transceiver integrated unit is set to the transmitting path, the broadband transceiver component generates an intermediate frequency signal, and after up-conversion with the local oscillator signal, a radio frequency excitation signal is obtained, which is distributed and transmitted to the delay module in the subarray unit after passing through the power division and synthesis network unit;

[0043] The delay module outputs the excitation signal after delay to the digital control delay channel in the up-down conversion module, and then outputs it to the TR component after power division, and the TR component outputs the excitation signal to the antenna after phase shift and power amplification for transmission;

[0044] If the phased array is in the receiving state, the broadband transceiver component in the monitoring and broadband transceiver integrated unit is set to the receiving path, the TR component transmits the radio frequency echo signal received by the antenna to the delay channel of the up-down conversion module, the signal is transmitted to the delay module after attenuation, amplification, delay, and synthesis for analog delay, and four analog beam radio frequency signals of sum, azimuth difference, elevation difference, and double difference are formed through the power division and synthesis network unit and transmitted to the broadband transceiver component of the monitoring and broadband transceiver integrated unit, and after sampling, digital down-conversion, filtering, and decimation processing of the four analog beam radio frequency signals, the signals are transmitted to the outside for subsequent processing.

[0045] Further, when the phased array works in the distributed narrowband mode:

[0046] The clock signal is transmitted to the digital transceiver module in the subarray unit through the power division and synthesis network unit;

[0047] The local oscillator signal is transmitted to the frequency conversion module through the power division and synthesis network unit;

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

[0049] If the phased array is in the transmitting state, the digital transceiver module in the subarray unit generates an intermediate frequency signal, and after up-conversion with the local oscillator signal, obtains multiple radio frequency excitation signals through power division; the excitation signals are output to the TR component, and the TR component outputs the excitation signals to the antenna after phase shifting and power amplification for transmission;

[0050] If the phased array is in the receiving state, the TR component receives the radio frequency echo signal received by the antenna and synthesizes a radio frequency signal after amplitude and phase modulation, the variable frequency module performs analog synthesis, attenuation, and amplification on the radio frequency signal delivered by the TR component, and obtains multiple intermediate frequency signals after twice down-conversion, the digital transceiver module obtains digital signals after sampling the intermediate frequency signals, and performs digital down-conversion, filtering, and decimation on the digital signals, and transmits the processed signals to the digital beam synthesis unit to form a digital beam, and then transmits the digital beam to the outside for subsequent processing.

[0051] Further, when the phased array works in the distributed wideband mode:

[0052] The clock signal is transmitted to the digital transceiver module in the subarray unit through the power division synthesis network unit;

[0053] The local oscillator signal is delivered to the variable frequency module through the power division synthesis network unit;

[0054] The switch group in the up-down conversion module is switched to the variable frequency channel;

[0055] If the phased array is in the transmitting state, the digital transceiver module in the subarray unit generates an intermediate frequency signal, and after up-conversion with the local oscillator signal, obtains multiple radio frequency excitation signals through power division; the excitation signals are output to the TR component, and the TR component outputs the excitation signals to the antenna after phase shifting and power amplification for transmission;

[0056] If the phased array is in the receiving state, the TR component receives the radio frequency echo signal received by the antenna and synthesizes a radio frequency signal after amplitude and phase modulation, the variable frequency module performs analog synthesis, attenuation, and amplification on the radio frequency signal delivered by the TR component, and obtains multiple intermediate frequency signals after twice down-conversion, the digital transceiver module obtains digital signals after sampling the intermediate frequency signals, and performs digital down-conversion, filtering, and decimation on the digital signals, and transmits the processed signals to the digital beam synthesis unit to form a digital beam, and then transmits the digital beam to the outside for subsequent processing.

[0057] Further, when the phased array works in the transmitting monitoring mode:

[0058] The phased array works according to the distributed narrowband mode, traverses each channel and each frequency point, and transmits signals in turn;

[0059] The transmitted radio frequency signal is coupled to the first-stage power division and synthesis network through the coupler integrated in the antenna, sequentially passes through the second-stage and third-stage power division and synthesis networks, and is transmitted to the monitoring assembly in the monitoring and wideband transceiver integrated unit;

[0060] The monitoring assembly works in a receiving path, multiplexes the sum beam receiving channel of the wideband transceiver assembly, receives the radio frequency signal coupled to the monitoring assembly, and sequentially performs down-conversion, digital sampling and digital processing;

[0061] The monitoring assembly receives the processed digital signal and transmits it to a subsequent processing module to analyze the amplitude and phase information, which is used for phased array transmitting amplitude and phase analysis and phase calibration.

[0062] Further, when the phased array works in a receiving monitoring mode:

[0063] The phased array works according to a distributed narrowband mode, iteratively works according to each channel and each frequency point, and sequentially receives signals.

[0064] The monitoring assembly in the monitoring and wideband transceiver integrated unit multiplexes the sum beam transmitting channel of the wideband transceiver assembly, generates a radio frequency signal of a controlled frequency point, and feeds the radio frequency signal into the coupler integrated in the antenna through the power division and synthesis network.

[0065] The coupler signal is fed into a receiving link in the distributed narrowband mode, the array surface is sequentially controlled to open different receiving channels, and the signals are sequentially received and transmitted to the digital beam synthesis unit.

[0066] The digital beam synthesis unit performs amplitude and phase analysis to obtain the amplitude and phase of the receiving channels of the full array surface at multiple working frequency points, which is used for phased array receiving amplitude and phase analysis and calibration.

[0067] Compared with the prior art, the present application has the following advantages:

[0068] (1) Analog and digital dual-link subarray level compensation technology: The present application adopts subarray level analog and digital dual-link compensation design, integrates an analog delay module (real-time delay compensation) and a digital module ("frequency shift and phase shift" + high-precision compensation) at the subarray level, and switches them through a switch group as needed:

[0069] Analog link: The delay line is used to quickly compensate for large span delay difference, and an analog synthesis network and a centralized wideband receiver are used to receive echo signals.

[0070] Digital link: Through a digital compensation algorithm ("frequency shift and phase shift"), a distributed analog de-skew, a distributed digital receiver and a DBF technology are used to realize echo reception.

[0071] Analog and digital dual-link backup, both in the form of linear frequency modulation and compatible with complex broadband waveform transmission and reception capabilities, strong interference countermeasures, customizable, redundant, and derivative of various products;

[0072] Different ways of compensating for aperture transit time can be selected as needed to improve range resolution and anti-interference capability;

[0073] (2) Distributed and centralized dual-probe link technology: This scheme uses integrated design of distributed broadband and centralized broadband, which can adapt to different application scenarios as needed, modular design, and customization as needed;

[0074] The distributed link is digitized at the subarray level, with flexible digital beamforming, high system anti-interference freedom, narrowband operation covering conventional search, and compatible broadband operation mode; The centralized link processes multiple subarray signals through the 2nd and 3rd power dividers (sum-difference synthesis), adapting to broadband anti-interference, high-precision tracking, and other scenarios;

[0075] Both can be flexibly customized through modular design: increase or decrease the number of subarrays (64-1536 channels) as needed, or switch the link operation mode.

[0076] (3) Distributed multi-signal integrated calibration network technology: It can realize real-time amplitude and phase calibration of two-dimensional arrays, and integrates local oscillator, clock, and broadband signals. That is, the local oscillator signal, clock signal, broadband probe signal, and amplitude and phase calibration signal are integrated in the three-level power divider synthesis network: The first level power divider synthesis network uses a microstrip line 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 errors of the TR components and delay modules in the subarray in real time (calibration period ≤1 second); The local oscillator, clock, and broadband signals are transmitted together, reducing the number of cables and power dividers, simplifying the network topology, reducing network complexity, and improving system stability.

[0077] From the performance point of view, this scheme can achieve radar detection with a range resolution of ≤0.2 meters, an angle resolution of ≤0.6°, and an anti-interference false alarm rate of ≤5%;

[0078] From the perspective of scene adaptation, this scheme supports multiple modes such as conventional search, high-precision tracking, and broadband complex waveform anti-interference, and the hardware can be customized as needed;

[0079] The calibration time of the phased array of this scheme is ≤1 second, the number of cables is reduced by 80%, and the system stability is improved by 40%, making it suitable for fixed, vehicle-mounted, and ship-mounted platforms;

[0080] The scheme of the application can be widely applied to low-altitude monitoring radars, unmanned aerial vehicle detection systems and other electronic devices, and provides high-performance detection solutions for low-altitude safety, city security, broadband data acquisition and other fields.

[0081] The application will be further described below in conjunction with the specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

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

[0083] Figure 2 It is a subarray unit architecture schematic diagram of the application.

[0084] Figure 3 It is a system working link schematic diagram of the application.

[0085] Figure 4 It is a link schematic diagram of the phased array in the centralized broadband working mode of the application.

[0086] Figure 5 It is a broadband transceiver component schematic diagram of the application.

[0087] Figure 6 It is a link schematic diagram of the phased array in the distributed narrowband and distributed broadband working mode of the application.

[0088] Figure 7 It is a link schematic diagram of the phased array in the monitoring working mode of the application. DETAILED DESCRIPTION

[0089] EMBODIMENT

[0090] The technical solutions in the embodiments of the application will be clearly and completely described below in conjunction with the drawings in the embodiments of the application. The described embodiments are only some of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work under the premise that the application falls within the scope of protection.

[0091] As shown in the application and claims, unless the context clearly indicates otherwise, the words “one”, “a”, “an” and / or “the” do not specifically refer to the singular, but also include the plural. Generally, the terms “comprise” and “include” only indicate the inclusion of the steps and elements explicitly identified, and these steps and elements do not constitute an exclusive list, and the method or device can also include other steps or elements.

[0092] The relative arrangement of parts and steps, numerical expressions, and numerical values set forth in the examples herein are not meant to limit the scope of the present application unless otherwise specifically stated. Also, it is to be understood that the use of the terms "preferably," "preferably," "more preferred," and "most preferred" are intended to convey that the described feature, characteristic, structure, or parameter is a preferred example, and that other features, characteristics, structures, or parameters can also be preferred within the scope of the present application. Moreover, it is to be understood that the use of the terms "first," "second," "third," etc., that preliminary terms such as "initially," "primarily," and the like, merely denote a claim of priority and cannot be taken to mean that the features or steps to which the terms refer must be in a listed order, unless otherwise specifically stated. The techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered as if the discussion were fully set forth herein. In the examples shown and discussed herein, any specific values should be interpreted as merely exemplary, and not as a limitation on the scope of the exemplary embodiments. Thus, other examples of the exemplary embodiments can have different values. It is to be noted that like reference numerals and letters refer to like items in the drawings, and, as such, once an item is defined in one drawing, it need not be discussed further in subsequent drawings.

[0093] In combination Figure 1 A two-dimensional wideband active digital phased array includes a plurality of subarray units, a power division and synthesis network unit, a monitoring and wideband transceiving integrated unit, a radar control unit, and a digital beam synthesis unit;

[0094] The subarray unit is configured to interact with the digital beam synthesis unit or the power division and synthesis network unit under the control of the radar control unit after processing the transceived electromagnetic wave signals.

[0095] The power division and synthesis network unit is configured to divide or synthesize signals from the monitoring and wideband transceiving integrated unit or the subarray unit.

[0096] The monitoring and wideband transceiving integrated unit is configured to implement monitoring signal generation / reception, wideband excitation signal generation, and echo reception.

[0097] In combination Figure 2 The subarray unit includes an antenna, a TR component, an analog delay module, a digital transceiving module, and an up-down conversion module.

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

[0099] The TR component, i.e., a transmit-receive component, includes 8-way transmission and 8-way reception in each component, and transceiving switching is implemented through a circulator. The main function of the TR component is to amplify and output radio frequency signals and to amplify and receive echo signals. In addition, each component includes a 6-bit digital controlled phase shifter for 8-way transmission, a 6-bit digital controlled phase shifter for 8-way reception, and a 6-bit digital controlled attenuator.

[0100] The TR assembly is connected with the antenna and the up-down conversion module in the integrated module through the radio frequency feeder in the first layer network, and the control of the TR assembly is directly controlled by the FPGA in the digital transceiver module, and the TR assembly is powered by the secondary power supply.

[0101] The up-down conversion module is used for realizing the frequency conversion of the uplink and downlink signals, and integrating the switch group to realize the switching of the distributed link and the centralized link. The up-down conversion module is connected with the TR assembly through the feeder in the first layer network, connected with the analog delay module in the integrated module through the radio frequency cable, and connected with the digital transceiver module through the radio frequency cable. The up-down conversion module is connected with the secondary power supply through the power supply cable. The FGPA in the digital transceiver module controls the digital attenuator and the switch in the up-down conversion module, and the secondary power supply supplies power to the up-down conversion module.

[0102] More specifically, the functions of the up-down conversion module in the embodiment include:

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

[0104] Function 2: In addition, the up-down conversion module also contains the STC (time sensitivity control) function, including a digital attenuator with a maximum of 31 dB and a step of 1 dB.

[0105] Function 3: The up-down conversion module integrates a 4-way 3-wavelength digital delay device, which can be used as a real-time delay for the centralized wideband link.

[0106] Function 4: The switch group is integrated to realize the switching of the distributed link and the centralized link.

[0107] The analog delay module is used to realize the real-time delay compensation in the centralized wideband working mode. The module contains a 5-bit digital analog delay device, and the maximum delay amount is 31 times the wavelength. The analog delay module is connected with the up-down conversion module in the integrated module through the radio frequency cable, connected with the digital transceiver and the secondary power supply module through the control cable to realize the control and power supply, and connected with the wideband transceiver module through the second layer and third layer power division and synthesis network.

[0108] The digital transceiver module is connected with the up-down conversion module through radio frequency, the control cable is connected with the TR assembly, the up-down conversion module and the analog delay module, the optical fiber is connected with the radar control unit and the digital beam synthesis unit, and the digital transceiver module is used for analyzing the radar control instruction transmitted by the uplink optical fiber, calculating and generating the beam control code, controlling the TR assembly, the up-down conversion module and the analog delay module to work according to the corresponding parameters and time sequence, and generating the intermediate frequency signal and receiving the intermediate frequency echo signal, and the digital transceiver module is used for carrying out analog-digital conversion, digital down conversion, filtering and packaging on the intermediate frequency echo signal, and then transmitting the intermediate frequency echo signal to the subsequent processing through the optical fiber.

[0109] The power division and synthesis network unit comprises a first-stage power division and synthesis network, a second-stage power division and synthesis network and a third-stage power division and synthesis network.

[0110] The first-stage power division and synthesis network is arranged between the antenna of the subarray unit and the TR assembly, and is used for realizing signal synthesis and power division within the subarray unit.

[0111] The second-stage power division and synthesis network and the third-stage power division and synthesis network are arranged between the subarray unit and the monitoring and wideband transceiver integrated unit in sequence.

[0112] The second-stage power division and synthesis network is used for realizing power division and synthesis of monitoring signals and wideband signals between multiple subarray units, and power division of clock signals, one local oscillator signal and two local oscillator signals.

[0113] The third-stage power division and synthesis network is used for completing centralized beam synthesis and transmission excitation signal power division, and realizing interaction with clock signals and local oscillator signals.

[0114] When the switch group is switched to the delay module, the phased array works in a centralized wideband mode.

[0115] When the switch group is switched to the intermediate frequency channel in the up-down conversion module, the phased array works in a distributed narrowband mode, a distributed wideband mode, a transmission monitoring mode or a reception monitoring mode.

[0116] Correspondingly, in combination with Figure 3 , the working link of the system is divided into a distributed narrowband working link, a distributed wideband working link and a centralized wideband working link, and the monitoring link of the system is divided into a transmission monitoring link and a reception monitoring link. When working in the centralized wideband working link, the switch group is switched to the delay module. In the distributed narrowband, the distributed wideband, the transmission monitoring and the reception monitoring links, the switch group is switched to the intermediate frequency channel in the up-down conversion module.

[0117] More specifically, in combination with Figure 4The centralized broadband link is one of the broadband working links of the system. The system adopts analog desloping technology to realize the linear frequency modulation signal detection capability of maximum 3 GHz instantaneous bandwidth, adopts broadband direct sampling technology to realize the broadband complex waveform detection capability of maximum 1 GHz instantaneous bandwidth, and also has broadband detection and interception capability. The link connection relationship is different from the distributed narrowband working link. At this time, the switch group is switched to the delay module;

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

[0119] The clock signal is transmitted to the digital transceiver module in the subarray unit through the power division and synthesis network unit. The digital transceiver module has the functions of controlling the delay module, the TR assembly and the frequency conversion module.

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

[0121] The switch group in the frequency conversion module is switched to the delay module channel.

[0122] The one local oscillator signal and the two local oscillator signals are transmitted to the broadband transceiver assembly of the monitoring and broadband transceiver integrated unit through the cable. The broadband transceiver assembly has the functions of 1-way transmission and 4-way reception, as shown in Figure 5 , which includes 1-way transmission excitation generation (intermediate frequency signal generation, up-conversion and power amplification), 4-way echo reception (including low noise amplification, down-conversion and ADC).

[0123] The digital transceiver module in the subarray unit determines the delay value and the phase shift value based on the radar control unit and transmits them to the TR assembly, the frequency conversion module and the delay module. Each TR assembly in the embodiment includes 8-way transceiver phase shifters and 8-way receiving attenuators. Each frequency conversion module includes 4-way 3-wavelength delay modules. Each delay module includes 4-way 31-wavelength delay modules.

[0124] If the phased array is in the transmission state, the broadband transceiver assembly in the monitoring and broadband transceiver integrated unit is set to the transmission path. The broadband transceiver assembly 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 division and synthesis network unit, the excitation signal is distributed and transmitted to the delay module in the subarray unit.

[0125] The delay module delays the excitation signal and outputs it to the digital control delay channel in the frequency conversion module, and then divides and outputs it to the TR assembly. The TR assembly outputs the excitation signal after phase shifting and power amplification to the antenna for transmission.

[0126] Specifically, the wideband transceiver component generates one intermediate frequency signal based on the DAC under the control of the radar control unit, and the intermediate frequency signal can be a wideband signal (maximum 1GHz) or a point frequency according to actual detection requirements; when the radar operating signal bandwidth is less than or equal to 1GHz, one local oscillator is a point frequency and the intermediate frequency signal is a wideband signal; when the radar operating signal bandwidth is greater than 1GHz, one local oscillator is a linear frequency modulation signal (greater than 1GHz) and the intermediate frequency signal is a point frequency;

[0127] The 1-path intermediate frequency signal is twice up-converted with the point frequency two local oscillators and one local oscillator to obtain 1-path radio frequency excitation signal, which is distributed to the delay module of each subarray unit through the power division and synthesis network unit;

[0128] In the delay module, the excitation signal is transmitted to the up-down conversion component after real-time delay;

[0129] In the up-down conversion component, the excitation signal is power divided into 4 paths, and each of the 4 paths is delayed and controlled to obtain 8 paths of excitation signals, which are respectively sent to eight-channel TR components. In each TR component, 1-path excitation signal is distributed into 8 paths of excitation signals and output after phase shift and power amplification. Therefore, each subarray scale is 8x8;

[0130] If the phased array is in a receiving state, the wideband transceiver component in the monitoring and wideband transceiver integrated unit is set to a receiving path, the TR component transmits the radio frequency echo signal received by the antenna to the delay channel of the up-down conversion module, the signal is transmitted to the delay module after attenuation, amplification, delay and synthesis to perform analog delay, and four analog beam radio frequency signals of sum, azimuth difference, elevation difference and double difference are formed through the power division and synthesis network unit and transmitted to the wideband transceiver component of the monitoring and wideband transceiver integrated unit. After sampling, digital down-conversion, filtering and decimation processing of the four analog beam radio frequency signals, the signals are transmitted to the outside for subsequent processing;

[0131] Specifically in this embodiment:

[0132] 1) Each eight-channel T / R component performs low-noise reception and amplitude and phase modulation on the radio frequency echo signals received by the 8 antenna units to synthesize 1-path radio frequency signal;

[0133] 2) The up-down conversion module analog synthesizes the radio frequency signals sent by each two T / R components into 4 paths of radio frequency signals, and then into 1-path signal radio frequency echo signal after passing through the delay unit and transmitting to the delay module;

[0134] 3) The delay module outputs the echo signal after delay;

[0135] 4) The radio frequency echo signals of each subarray form four analog beam radio frequency signals of sum, azimuth difference, elevation difference and double difference through the power division and synthesis network.

[0136] 5) Wideband transceiver module samples 4 RF signals to get digital signals (ADC), and processes the digital signals by digital down conversion, filtering and decimation.

[0137] 6) The digital signals are transmitted to subsequent processing modules through an optical transmission network for algorithm processing.

[0138] The distributed narrowband link is the basic working link of the system, which is used for narrowband search and discovery. At this time, the switch group is switched to the frequency conversion channel of the up-down conversion module. The narrowband link is divided into transmitting and receiving states, and the working link diagram is shown in Figure 6 When the phased array works in the distributed narrowband mode:

[0139] The clock signal is transmitted to the digital transceiver module in the subarray unit through the power division and synthesis network unit;

[0140] The local oscillator signal is transmitted to the frequency conversion module through the power division and synthesis network unit;

[0141] The switch group in the up-down conversion module 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 division and synthesis network unit, and the number of digital transceiver channels is 4;

[0143] The point frequency one local oscillator and the point frequency two local oscillator signals are transmitted to the frequency conversion module through the power division and synthesis network unit, and the number of frequency conversion module channels is 4;

[0144] If the phased array is in the transmitting state, the digital transceiver module in the subarray unit generates an intermediate frequency signal, which is up-converted with the local oscillator signal and then divided into multiple RF excitation signals through power division; The excitation signal is output to the TR component, and the TR component outputs the excitation signal to the antenna after phase shifting and power amplification;

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

[0146] 1) The digital transceiver component of each subarray generates 4 intermediate frequency signals based on the DAC under the control of the radar control unit;

[0147] 2) In the 4-channel frequency conversion of each subarray, 4 intermediate frequency signals are up-converted twice and then divided into 8 RF excitation signals through power division;

[0148] 3) The 8 RF excitation signals of each subarray are respectively distributed into 8 excitation signals in 8 eight-channel T / R components and output after phase shifting and power amplification, and the scale of each subarray is 8x8;

[0149] If the phased array is in a receiving state, the TR component receives and amplitude-phase modulates the radio frequency echo signal received by the antenna to synthesize a radio frequency signal, the frequency conversion module performs analog synthesis, attenuation, amplification on the radio frequency signal delivered by the TR component, and obtains multiple intermediate frequency signals through twice down-conversion, the digital transceiver module obtains digital signals through sampling on the intermediate frequency signals, and then performs digital down-conversion, filtering and decimation on the digital signals, and transmits the processed signals to the digital beam synthesis unit to form a digital beam, and then transmits to the outside for subsequent processing;

[0150] Specifically in this embodiment, it comprises:

[0151] 1) Each eight-channel T / R component receives and processes the echo signal received by the eight antenna units, such as low-noise reception and amplitude-phase modulation, to synthesize one radio frequency signal;

[0152] 2) The frequency conversion module performs analog synthesis on the radio frequency signals delivered by each two T / R components, and then obtains four intermediate frequency signals through twice down-conversion;

[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 signals are transmitted to the DBF through the optical transmission network to form a digital beam, and finally transmitted to the subsequent processing module for algorithm processing.

[0155] The distributed wideband link is one of the wideband working links of the system, and the system realizes wideband transmission and reception synthesis through digital frequency shift and phase shift, analog slope removal processing, which not only realizes the wideband detection capability of instantaneous wideband signal, but also reduces the intermediate frequency bandwidth requirement of the transmitter and receiver, improves the efficiency and cost ratio of the system, and maximizes the wideband detection capability of 3GHz bandwidth linear frequency modulation signal. The link connection relationship is the same as that of the distributed narrowband working link, that is, as shown in Figure 6 When the phased array works in the distributed wideband mode:

[0156] The clock signal is transmitted to the digital transceiver module in the subarray unit through the power division and synthesis network unit;

[0157] The local oscillator signal is delivered to the frequency conversion module through the power division and synthesis network unit;

[0158] The switch group in the up-down conversion module is switched to the frequency conversion channel;

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

[0160] The wideband local oscillator and the point frequency local oscillator signal are delivered to the frequency conversion module through the power division and synthesis network unit, and the number of frequency conversion module channels is 4;

[0161] If the phased array is in the transmitting state, the digital transceiver module in the subarray unit generates an intermediate frequency signal, and after up-conversion with the local oscillator signal, multiple radio frequency excitation signals are obtained through power division; the excitation signals are output to the TR component, and the TR component outputs the excitation signals to the antenna after phase shifting and power amplification for transmission;

[0162] Specifically in this embodiment, it includes:

[0163] 1) The digital transceiver component of each subarray generates 4 routes of intermediate frequency signals after frequency shifting and phase shifting based on the DAC under the control of the timing of the radar control;

[0164] 2) In the 4-channel frequency conversion of each subarray, the 4 routes of intermediate frequency signals are up-converted twice with the point frequency two local oscillators and the linear frequency modulation broadband one local oscillator, and 8 routes of radio frequency excitation signals are obtained through power division;

[0165] 3) The 8 routes of radio frequency excitation signals of each subarray are respectively distributed into 8 routes of excitation signals in 8 eight-channel T / R components and output after phase shifting and power amplification, and each subarray has a scale of 8x8;

[0166] If the phased array is in the receiving state, the TR component receives the radio frequency echo signal received by the antenna, performs amplitude and phase modulation, and synthesizes a radio frequency signal, the frequency conversion module performs analog synthesis, attenuation, amplification on the radio frequency signal transmitted by the TR component, and obtains multiple intermediate frequency signals after analog de-skewing through twice down-conversion, the digital transceiver module samples the intermediate frequency signals to obtain digital signals, and then performs digital down-conversion, filtering and decimation, and transmits the processed signals to the digital beam synthesis unit to form a digital beam, and then transmits to the outside for subsequent processing.

[0167] Specifically in this embodiment, it includes:

[0168] 1) Each eight-channel T / R component performs low-noise reception and amplitude and phase modulation on the echo signals received by the 8 antenna units, and synthesizes 1 route of radio frequency signals;

[0169] 2) The frequency conversion module performs analog synthesis on the radio frequency signals sent by each two T / R components, and then performs twice down-conversion with the linear frequency modulation broadband one local array and the point frequency two local oscillators to obtain 4 routes of intermediate frequency signals after analog de-skewing;

[0170] 3) The digital transceiver component samples the 4 routes of analog intermediate frequency signals to obtain digital signals (ADC), and performs frequency shifting and phase shifting, digital down-conversion, filtering and decimation on the digital signals.

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

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

[0173] The transmission monitoring link is based on the distributed narrowband link, and a coupler, a monitoring feeder network (integrated in the power division and synthesis network), and a monitoring component are added. The link schematic diagram is shown in Figure 7 The monitoring component and the broadband transceiver component are physically multiplexed. When the phased array works in the transmission monitoring mode:

[0174] The phased array works according to the distributed narrowband mode, traverses each channel and each frequency point, and transmits signals in turn.

[0175] The transmitted radio frequency signal is coupled to the first-stage power division and synthesis network through the coupler integrated in the antenna, sequentially passes through the second-stage and third-stage power division and synthesis networks, and is transmitted to the monitoring component in the monitoring and broadband transceiver integrated unit.

[0176] The monitoring component works in the receiving path, multiplexes the sum beam receiving channel of the broadband transceiver component, receives the radio frequency signal coupled to the monitoring, and sequentially performs frequency down-conversion, digital sampling, and digital processing.

[0177] The digital signal received and processed by the monitoring component is transmitted to a subsequent processing module, and amplitude and phase information is obtained by analysis, that is, the amplitude and phase of N transmission channels of the full array at F working frequency points, which is used for phased array transmission amplitude and phase analysis and phase calibration.

[0178] The reception 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 the system performance.

[0179] The reception monitoring link is based on the distributed narrowband link, and a coupler, a monitoring feeder network (integrated in the power division and synthesis network), and a monitoring component are added. The link schematic diagram is shown in Figure 6 The monitoring component and the broadband transceiver component are physically multiplexed. The main lobe-to-side lobe ratio of the beam is greater than or equal to 25 dB through the rapid feedback correction of the reception monitoring link.

[0180] When the phased array works in the reception monitoring mode:

[0181] The phased array works according to the distributed narrowband mode, traverses each channel and each frequency point, and receives signals in turn.

[0182] The monitoring component in the monitoring and broadband transceiver integrated unit multiplexes the sum beam transmission channel of the broadband transceiver component, generates a radio frequency signal of a controlled frequency point, and feeds the radio frequency signal into the coupler integrated in the antenna through the power division and synthesis network.

[0183] The coupler signal is fed into the receiving link in the distributed narrowband mode, the array is controlled to open different receiving channels in turn, and the signal is received in turn and transmitted to the digital beam synthesis unit;

[0184] The digital beam synthesis unit performs amplitude and phase analysis to obtain the amplitudes and phases of the N receiving channels of the full array at the F operating frequency points, which are used for the analysis and calibration of the phased array receiving amplitude and phase.

[0185] The scheme has good performance, high scene adaptation, good engineering application prospect, and can be widely applied to electronic equipment such as low-altitude surveillance radars and unmanned aerial vehicle detection systems, and provides high-performance detection solutions for low-altitude safety, urban security, broadband data acquisition and other fields.

[0186] The above-described embodiments only express one embodiment of the present application, and the description is more specific and detailed, but it cannot be understood as limiting the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A two-dimensional wideband active digital phased array, characterized by, The subarray unit, the power division and combination network unit, the monitoring and wideband transceiving integrated unit, the radar control unit and the digital beam combination unit are included. The subarray unit is used for processing and interacting with the digital beam combination unit or the power division and combination network unit under the control of the radar control unit. The power division and combination network unit is used for dividing or combining the signals from the monitoring and wideband transceiving integrated unit or the subarray unit. The monitoring and wideband transceiving integrated unit is used for realizing the monitoring signal generation / reception, the wideband excitation signal generation and the echo reception.

2. The two-dimensional wideband active digital phased array of claim 1, wherein, The subarray unit includes an antenna, a TR component, an analog delay module, a digital transceiving module and an up-down conversion module. The antenna and the TR component are connected to realize the transmission and reception of radio frequency signals. The TR component and the up-down conversion module are connected and controlled by the digital transceiving module. The up-down conversion module is used for realizing the frequency conversion of uplink and downlink signals and switching the distributed link and the centralized link through the integrated switch group. The analog delay module is used for real-time delay compensation and is connected with the power division and combination network and controlled by the digital transceiving module.

3. The two-dimensional wideband active digital phased array of claim 2, wherein, The digital transceiving module is connected with the up-down conversion module through radio frequency, connected with the TR component, the up-down conversion module and the analog delay module through control cable and connected with the radar control unit and the digital beam combination unit through optical fiber. The digital transceiving module is used for analyzing the radar control instructions transmitted through the uplink optical fiber, calculating and generating the beam control code, controlling the TR component, the up-down conversion module and the analog delay module to work according to the corresponding parameters and time sequence, generating intermediate frequency signals, receiving intermediate frequency echo signals, performing analog-digital conversion, digital down-conversion, filtering and packaging and transmitting to the subsequent processing through the optical fiber. The power division and combination network unit includes a first-stage power division and combination network, a second-stage power division and combination network and a third-stage power division and combination network. The first-stage power division and combination network is arranged between the antenna and the TR component of the subarray unit and is used for realizing the signal combination and division in the subarray unit. The second-stage power division and combination network and the third-stage power division and combination network are arranged between the subarray unit and the monitoring and wideband transceiving integrated unit.

4. The two-dimensional wideband active digital phased array of claim 3, wherein, The second-stage power division and combination network is used for realizing the power division and combination of the monitoring signals and the wideband signals between multiple subarray units and the power division of the clock signal, the first local oscillator signal and the second local oscillator signal. The third-stage power division and combination network is used for completing the centralized and difference beam combination and the excitation signal division and realizing the interaction with the clock signal and the local oscillator signal.

5. The two-dimensional wideband active digital phased array of claim 4, wherein, When the switch group is switched to the connection delay module, the phased array works in the centralized wideband mode. When the switch group is switched to the connection variable frequency channel of the up-down conversion module, the phased array works in the distributed narrowband mode, the distributed wideband mode, the transmission monitoring mode or the reception monitoring mode. When the phased array works in the centralized wideband mode: The clock signal is transmitted to the digital transceiving module in the subarray unit through the power division and combination network unit. The local oscillator signal is transmitted to the monitoring and wideband transceiving integrated unit. The switch group in the up-down conversion module switches to the delay module channel; The digital transceiver module in the subarray unit determines the delay value and the phase shift value based on the radar control unit and transmits to the TR assembly, the up-down conversion module and the delay module; If the phased array is in the transmitting state, the wideband transceiver assembly in the monitoring and wideband transceiver integrated unit is set as a transmitting path, the wideband transceiver assembly generates an intermediate frequency signal, and after up-conversion with the local oscillator signal, a radio frequency excitation signal is obtained, which is distributed to the delay module in the subarray unit after passing through the power division and synthesis network unit; The delay module outputs the excitation signal after delay to the digital control delay channel in the up-down conversion module, and then divides the output to the TR assembly, which outputs the excitation signal after phase shift and power amplification to the antenna for transmission; If the phased array is in the receiving state, the wideband transceiver assembly in the monitoring and wideband transceiver integrated unit is set as a receiving path, the TR assembly transmits the radio frequency echo signal received by the antenna to the delay channel of the up-down conversion module, the signal is transmitted to the delay module for analog delay after passing through attenuation, amplification, delay and synthesis, and four analog beam radio frequency signals of sum, azimuth difference and elevation difference, double difference are formed by the power division and synthesis network unit and transmitted to the wideband transceiver assembly of the monitoring and wideband transceiver integrated unit, and after sampling, digital down-conversion, filtering and decimation processing of the four analog beam radio frequency signals, the processed signals are transmitted to the outside for subsequent processing.

6. The two-dimensional wideband active digital phased array of claim 4, wherein, When the phased array works in the distributed narrowband mode: The clock signal is transmitted to the digital transceiver module in the subarray unit through the power division and synthesis network unit; The local oscillator signal is transmitted to the conversion module through the power division and synthesis network unit; The switch group in the up-down conversion module switches to the conversion channel; If the phased array is in the transmitting state, the digital transceiver module in the subarray unit generates an intermediate frequency signal, and after up-conversion with the local oscillator signal, a plurality of radio frequency excitation signals are obtained by power division; the excitation signals are output to the TR assembly, which outputs the excitation signals after phase shift and power amplification to the antenna for transmission; If the phased array is in the receiving state, the TR assembly receives the radio frequency echo signal received by the antenna and modulates the amplitude and phase to synthesize a radio frequency signal, the conversion module performs analog synthesis, attenuation and amplification on the radio frequency signal transmitted by the TR assembly, and obtains a plurality of intermediate frequency signals after twice down-conversion, the digital transceiver module obtains digital signals after sampling the intermediate frequency signals, and performs digital down-conversion, filtering and decimation, and transmits the processed signals to the digital beam synthesis unit to form a digital beam, and then transmits the processed signals to the outside for subsequent processing.

7. The two-dimensional wideband active digital phased array of claim 4, wherein, When the phased array works in the distributed wideband mode: The clock signal is transmitted to the digital transceiver module in the subarray unit through the power division and synthesis network unit; The local oscillator signal is transmitted to the conversion module through the power division and synthesis network unit; The switch group in the up-down conversion module switches to the conversion channel; If the phased array is in the transmitting state, the digital transceiver module in the subarray unit generates an intermediate frequency signal, and after up-conversion with the local oscillator signal, a plurality of radio frequency excitation signals are obtained by power division; The excitation signals are output to the TR assembly, which outputs the excitation signals after phase shift and power amplification to the antenna for transmission; If the phased array is in a receiving state, the TR component receives and amplitude-phase modulates the radio frequency echo signal received by the antenna to synthesize a radio frequency signal, the variable frequency module analog synthesizes, attenuates, and amplifies the radio frequency signal delivered by the TR component, and obtains multiple intermediate frequency signals after analog desquamation through twice down-conversion, the digital transceiver module obtains digital signals after sampling the intermediate frequency signals, and performs digital down-conversion, filtering, and decimation on the digital signals, and transmits the processed signals to the digital beam synthesis unit to form a digital beam, and then transmits to the outside for subsequent processing.

8. The two-dimensional wideband active digital phased array of claim 4, wherein, When the phased array works in a transmitting monitoring mode: The phased array works according to the distributed narrowband mode, traverses each channel and each frequency point, and transmits signals in turn; The transmitted radio frequency signal is coupled to the first-stage power division and synthesis network through the coupler integrated in the antenna, sequentially passes through the second-stage and third-stage power division and synthesis networks, and is transmitted to the monitoring component in the monitoring and wideband transceiver integrated unit; The monitoring component works in a receiving path, multiplexes the sum beam receiving channel of the wideband transceiver component, receives the radio frequency signal coupled to the monitoring component, and sequentially performs down-conversion, digital sampling, and digital processing; The monitoring component transmits the processed digital signal to a subsequent processing module, analyzes to obtain amplitude and phase information, and is used for phased array transmitting amplitude and phase analysis and phase calibration.

9. The two-dimensional wideband active digital phased array of claim 4, wherein, When the phased array works in a receiving monitoring mode: The phased array works according to the distributed narrowband mode, traverses each channel and each frequency point, and receives signals in turn; The monitoring component in the monitoring and wideband transceiver integrated unit multiplexes the sum beam transmitting channel of the wideband transceiver component, generates a radio frequency signal of a controlled frequency point, and feeds the radio frequency signal into the coupler integrated in the antenna through the power division and synthesis network; The coupler signal is fed into the receiving link in the distributed narrowband mode, the array surface sequentially opens different receiving channels under control, receives signals in turn, and transmits the signals to the digital beam synthesis unit; The digital beam synthesis unit performs amplitude and phase analysis to obtain the amplitude and phase of the receiving channel of the full array surface at multiple working frequency points, which is used for phased array receiving amplitude and phase analysis and calibration.

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