CN114578337A - Digital multi-beam low-small-slow detection radar capable of transmitting phase-scanning wide beam and receiving wide beam - Google Patents

Abstract

The invention discloses a digital multi-beam 'low-small-slow' detection radar for transmitting phase-scanning wide beams and receiving the wide beams. The digital signal processing unit generates a transmitting digital intermediate frequency signal, and the transmitting digital intermediate frequency signal is converted into an analog signal by the high-speed DA module and then is sent to the analog phase modulation unit. The beam control unit can control the analog phase change to realize the directional change of the transmitted wide beam and close part of the transmitting array elements to realize the change of the coverage range of the transmitting angle by controlling the analog phase modulation unit; the beam control unit can flexibly form m paths of digital narrow beams by controlling the beam synthesis unit and can control the beam pointing in real time.

Description

Transmit Phase Sweep Wide Beam Receiving Digital Multi-beam "Low, Small, Slow" Detection Radar

technical field

The invention belongs to the technical field of detection radar, in particular to a "low, small, slow" detection radar of transmitting phase sweep wide beam receiving digital multi-beam.

Background technique

Phased array radar is a phase-controlled electronically scanned array radar, which uses a large number of individually controlled small antenna units arranged into an antenna array. Each antenna unit is controlled by an independent phase-shift switch. By controlling the phase emitted by each antenna unit, it can be Combine beams of different directions.

Digital beamforming technology is widely used in the field of radar signal processing. It can digitally change the amplitude and phase between antenna elements, and simultaneously form multiple beams at different elevation and azimuth angles. Traditional beamforming has lower flexibility and accuracy than data beamforming techniques.

Phased array radar has the advantages of electronic scanning, and digital beamforming has the advantage of simultaneous multi-beam, but phased array radar has only one beam to scan the entire airspace, so the time efficiency is too low; digital beamforming has several beams, time Very resource efficient, but consumes too many analog channels.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a "low, small and slow" detection radar based on transmitting phase sweep wide beam and receiving digital multi-beam, this circuit can take into account the advantages of phased array radar and digital beam radar.

The technical solution to achieve the purpose of the present invention is: a transmitting phase sweep wide beam receiving digital multi-beam "low, small and slow" detection radar. The "low, small and slow" detection radar consists of a transmitting antenna array of N array elements, a receiving antenna array of M array elements, an analog phase modulation unit, M channels of analog channels, a high-speed AD module, a high-speed DA module, and a digital signal processing unit. , a beam steering unit and a beam combining unit. First, the digital signal processing unit generates the transmit intermediate frequency signal, which is converted into an analog signal by the high-speed DA module, and then sent to the analog phase modulation unit; secondly, the beam control unit controls the analog phase modulation unit, and converts the analog signal into N channels after phase modulation. The radio frequency signal is then transmitted through the transmitting antennas of the N array elements; the beam control unit realizes a wide beam (the wide beam angle coverage is θ ₁ ) by adjusting the phase of the N channels of analog signals to scan in space, and by turning off the N channels of signals A number of channels are used to transmit a wide beam coverage angle range change (after the change, the wide beam angle coverage is θ ₂ , θ ₂ > θ ₁ ); then, the receiving antenna fronts of the M array elements receive echo signals from the target , and send it to the M channel analog channel. The M channel analog channel converts the received M channel echo RF signal into an intermediate frequency signal, and sends it to the high-speed AD module. The high-speed AD module converts the M channel analog intermediate frequency signal into a digital signal. Finally, the beam synthesizing unit synthesizes the input digital signals of the M array elements into m channels of digital narrow beams (the narrow beam angle coverage is θ ₃ , θ ₃ << θ ₁ ) pointing to signal and output. The beam control unit controls the beam synthesizing module to point the input M channels of IF digital signals to synthesize m channels of digital narrow beams according to the transmit beam direction (the sum of the angles covered by the m channels of narrow beams is θ ₄ , θ ₄ ≥ θ ₁ ).

Further, the analog phase modulation unit adjusts the direction of the antenna wide beam launch angle by controlling the analog phase of the transmitted signal, so as to realize scanning in the entire airspace; realize the change of the transmission wide beam coverage angle range by closing some of the N-way signals. After the change, the wide beam angle coverage is θ ₂ , θ ₂ >θ ₁ ).

Further, the beam control unit realizes the scanning of a transmission wide beam (the wide beam angle coverage is θ ₁ ) in space by adjusting the phase of the N channels of analog signals, and realizes the transmission of a wide beam coverage angle range by closing several channels of the N channels of analog signals. (the wide beam angle coverage after transformation is θ ₂ , θ ₂ > θ ₁ ); by controlling the beam synthesis module, the input M channels of intermediate frequency digital signals are directed to synthesize m channels of digital narrow beams according to the direction of the transmitting beam.

Further, the beam synthesizing unit synthesizes the input digital signals of the M array elements into m channels of digital narrow beams (each narrow beam angle coverage is θ ₃ , θ ₃ << θ ₁ ; and the angles covered by the m channels of narrow beams and is θ ₄ , θ ₄ ≥ θ ₁ ), and can cover the coverage of the wide beam, and with the change of the direction of the wide beam, the m-channel narrow beam changes synchronously with the change of the direction of the wide beam, and can still cover the wide beam The coverage of the beam.

Compared with the prior art, the present invention has significant advantages: the present invention takes into account the advantages of the phased array radar and the digital multi-beam radar at the same time, and at the same time, the time efficiency is better than that of the phased array radar, the cost is lower than that of the digital multi-beam radar, and the High applicability and versatility, high time efficiency, high flexibility and precision, the beam control unit in the present invention can control the analog phase change by controlling the analog phase modulation unit to realize the direction change of the wide beam and the closing part The transmission array element realizes the change of the transmission angle coverage; the beam control unit can flexibly form m-channel digital narrow beams by controlling the beam synthesis unit, and can control the beam pointing in real time.

Description of drawings

1 is a schematic diagram of the overall structure of the transmitting phase sweep wide beam receiving digital multi-beam "low, small and slow" detection radar of the present invention;

2 is a schematic structural diagram of an analog phase modulation unit of the present invention;

Fig. 3 is the transmission beam broadening of the present invention and the original transmission beam pattern;

4 is a schematic structural diagram of a beam forming unit of the present invention;

FIG. 5 is a pattern of simultaneous coverage of wide beam and narrow beam according to the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer and clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

As shown in Figure 1-5, a transmitting phase sweep wide beam receiving digital multi-beam "low, small and slow" detection radar includes: transmitting antenna fronts of N array elements, receiving antenna fronts of M array elements, analog Phase modulation unit, M analog channels, high-speed AD module, high-speed DA module, digital signal processing unit, beam control unit and beam forming unit. First, the digital signal processing unit generates and transmits a digital intermediate frequency signal, which is converted into an analog signal by the high-speed DA module Then, it is sent to the analog phase modulation unit; secondly, the beam control unit controls the analog phase modulation unit, converts the analog signal into N-channel phase-modulated radio frequency signals, and then transmits it through the transmitting antennas of N array elements; the beam control unit passes Adjust the phase of the N-channel analog signal to achieve a wide beam (the wide beam angle coverage is θ1) in space, and by closing several channels of the N-channel signal to achieve a wide beam coverage angle range change (after the change, the wide beam angle coverage is θ2, θ2>θ1); then, the receiving antenna fronts of the M array elements receive the echo signals from the target, and send them into the M channels of analog channels, and the M channels of analog channels convert the received M channels of RF echo signals It is an intermediate frequency signal, which is sent to the high-speed AD module. The high-speed AD module converts the M channels of analog intermediate frequency signals into digital signals, and then sends them to the beamforming unit of the digital signal processing module; The signal is synthesized into m (m is determined according to the receiving coverage and the beam interval) channels of digital narrow beams (the narrow beam angle coverage is θ3, θ3 << θ1) pointing to the signal and output, wherein the beam control unit controls the beam synthesis module to the input signal. M channels of intermediate frequency digital signals are directed to synthesize m channels of digital narrow beams according to the direction of the transmitting beam (the sum of the angles covered by the m channels of narrow beams is θ4, and θ4≥θ1).

By controlling the analog phase of the transmitted signal, the analog phase modulation unit adjusts the direction of the antenna wide beam launch angle to achieve scanning in the entire airspace; by closing some of the N channels, the coverage angle range of the wide beam can be changed (after the change, the wide beam coverage angle is changed. The beam angle coverage is θ2, θ2>θ1).

The beam control unit realizes a wide beam (the wide beam angle coverage is θ1) by adjusting the phase of the N channels of analog signals to scan in space, and by closing several channels of the N channels of analog signals to achieve a wide beam coverage angle range change (transformation). The angle coverage of the rear wide beam is θ2, θ2>θ1); the input M channels of intermediate frequency digital signals are weighted by amplitude and phase by controlling the beam synthesis module, and m channels of digital narrow beams are synthesized according to the direction of the transmitting beam.

The beam synthesis unit performs amplitude and phase weighting on the input digital signals of the M array elements, and synthesizes them into m channels of digital narrow beams (the angle coverage of each narrow beam is θ3, θ3 << θ1; and the angle sum of the m channels of narrow beam coverage is θ4, θ4≥θ1), and can cover the coverage of the wide beam, and the m-channel narrow beam will change synchronously with the change of the direction of the transmitted wide beam, and can still cover the coverage of the transmitted wide beam.

The invention is a transmitting phase sweep wide beam receiving digital multi-beam "low, small and slow" detection radar, which consists of a transmitting antenna front of N array elements, a receiving antenna front of M It is composed of analog channel, high-speed AD module, high-speed DA module, digital signal processing unit, beam control unit and beam synthesis unit. The specific structure is shown in Figure 1.

First, the digital signal processing unit generates an intermediate frequency transmission signal, which is converted into an analog signal by the high-speed DA module, and then sent to the analog phase modulation unit; secondly, the beam control unit controls the analog phase modulation unit, and converts the analog signal into N channels of phase modulation. The radio frequency signal is then transmitted through the transmitting antennas of the N array elements.

Figure 2 is the structure diagram of the analog phase modulation unit. The intermediate frequency analog signal output by the high-speed DA module first passes through the up-mixer to be mixed into a transmitting radio frequency signal, and then passes through a phase modulator (phase modulator) realized by a multiplier to transmit a signal. The signal is phase-modulated. The array of N array elements is composed of N groups of structures shown in Figure 2. The N phase-modulated outputs are connected to the N array elements and radiated by the antenna.

The beam control unit realizes the scanning of a wide beam (the wide beam angle coverage is θ ₁ ) in space by adjusting the phase change of the N channels of analog signals, and realizes the change in the coverage angle range of a wide beam by closing several channels of the N channels of signals ( After the change, the wide beam angle coverage is θ ₂ , θ ₂ >θ ₁ ). The original emission angle and the broadened emission angle are shown in Figure 3.

Then, the receiving antenna fronts of the M array elements receive the echo signals from the target and send them to the M channels of analog channels. module, the high-speed AD module converts the M channels of analog intermediate frequency signals into digital signals, and then sends them to the beam forming unit of the digital signal processing module.

Finally, the beam synthesizing unit synthesizes the input digital signals of the M array elements into signals directed by m channels of digital narrow beams (the narrow beam angle coverage is θ ₃ , θ ₃ << θ ₁ ), and outputs them. Figure 4 shows the beam synthesis Schematic diagram of the unit structure, M channels of intermediate frequency digital signals are multiplied by M amplitude and phase weighting coefficients and then added and output, and one narrow beam output is obtained. The beam control unit controls the beam synthesizing module to point the input M channels of IF digital signals to synthesize m channels of digital narrow beams according to the transmit beam direction (the sum of the angles covered by the m channels of narrow beams is θ ₄ , θ ₄ ≥ θ ₁ ).

The beam synthesizing unit synthesizes the digital signals of the input M array elements into m channels of digital narrow beams (each narrow beam angle coverage is θ ₃ , θ ₃ << θ ₁ ; and the sum of the angles covered by the m channels of narrow beams is θ ₄ , θ ₄ ≥ θ ₁ ), and can cover the coverage of the wide beam, and with the change of the direction of the wide beam, the m-way narrow beam changes synchronously with the change of the direction of the wide beam, and can still cover the coverage of the wide beam scope. Figure 5 is a pattern of simultaneous coverage of a wide beam and a narrow beam. Among them, the middle one is for receiving a narrow beam, and the narrow beam angle coverage is θ ₃ , and the outer one is for transmitting a wide beam, and the wide beam angle coverage is θ ₁ . The sum of the angles covered by the m-way narrow beams is θ ₄ (θ ₄ =m*θ ₃ )>θ ₁ (or θ ₂ ).

Claims (4)

1. A digital multi-beam 'slow-low' detection radar for transmitting phase-scanning wide-beam reception, comprising: firstly, a digital signal processing unit generates a transmitting digital intermediate frequency signal, and the transmitting digital intermediate frequency signal is converted into an analog signal by a high-speed DA module and then is sent to an analog phase modulation unit; secondly, the beam control unit controls the analog phase modulation unit to convert the analog signals into N paths of radio frequency signals after phase modulation, and then the radio frequency signals are transmitted out through transmitting antennas of N array elements; the wave beam control unit realizes the wide wave beam emission (the wide wave beam angle is covered by theta) by adjusting the phase of the N paths of analog signals₁) In the space scanning, the change of the coverage angle range of a wide beam is transmitted by closing a plurality of N paths of signals (the coverage angle of the wide beam after the change is theta)₂，θ₂＞θ₁) (ii) a Then, the receiving antenna array surface of M array elements receives echo signals from a target and sends the echo signals to M analog channels, the M analog channels convert the received M radio frequency echo signals into intermediate frequency signals and send the intermediate frequency signals to a high-speed AD module, the high-speed AD module converts the M analog intermediate frequency signals into digital signals and sends the digital signals to the beam combination of a digital signal processing moduleForming a unit; finally, the beam synthesis unit synthesizes the input digital signals of the M array elements into M (M is determined according to the receiving coverage range and the beam interval) paths of digital narrow beams (the narrow beam angle coverage is theta)₃，θ₃<<θ₁) And the beam control unit controls the beam synthesis module to directionally synthesize M digital narrow beams (the sum of the angles covered by the M narrow beams is theta) according to the transmitting beam direction for the input M intermediate frequency digital signals₄，θ₄≥θ₁)。

2. The digital multi-beam 'low-small-slow' detection radar capable of transmitting and phase-scanning wide-beam receiving according to claim 1, wherein the analog phase modulation unit adjusts the direction of the wide-beam transmitting angle of the antenna by controlling the analog phase of the transmitted signal so as to realize scanning in the whole airspace; the change of the coverage angle range of the transmitted wide beam is realized by closing a plurality of paths of partial N paths of signals (the coverage angle of the wide beam after the change is theta₂，θ₂＞θ₁)。

3. The digital multi-beam low-small-slow detection radar for transmitting and phase-scanning wide-beam reception according to claim 1, wherein the beam control unit implements a transmitting wide beam (wide beam angular coverage is θ) by adjusting the phases of the N analog signals₁) In the space scanning, the change of a wide beam covering angle range is realized by closing a plurality of N paths of analog signals (the wide beam angle coverage after conversion is theta)₂，θ₂＞θ₁) (ii) a And the amplitude phase weighting is carried out on the input M paths of intermediate frequency digital signals by controlling the beam synthesis module, and M paths of digital narrow beams are synthesized according to the direction of the transmitted beam.

4. The radar according to claim 1, wherein the beam synthesis unit performs amplitude phase weighting on the input M array elements digital signals, and synthesizes M digital narrow beams (each narrow beam has an angle covering θ)₃，θ₃<<θ₁(ii) a And the sum of the angles covered by the m narrow beams is theta₄，θ₄≥θ₁) The coverage range of the wide beams can be covered, and the m paths of narrow beams can synchronously change along with the change of the pointing direction of the transmitted wide beams, and the coverage range of the transmitted wide beams can still be covered.

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