CN103312346A - Null-steering antenna - Google Patents

Abstract

The invention relates to a zeroing antenna. Use the down converter to convert the input signal of the antenna radiation unit from the high frequency band to the lower microwave frequency band; couple a part of the energy from each channel of the antenna, select the channel where the signal exists through the switch matrix, and collect the signal after orthogonalization , using the multiple signal classification method to realize the estimation of the direction of arrival of the signal; according to the measurement results of the direction of arrival, the weight value is calculated by the conformal zeroing algorithm, and the microwave weight network is used to form a wider frequency band in the lower microwave frequency band. Null the beam. In the working mode of direction of arrival detection, the nulling antenna can actively locate the direction of the incoming wave signal; in the working mode of beam on-orbit reconstruction, the nulling antenna uses the microwave weight network to realize the real-time reconstruction of the beam, further The flexibility and anti-interference ability of the beam are enhanced.

Description

A zeroing antenna

technical field

The invention relates to an intelligent antenna, in particular to a zero-adjusting antenna capable of estimating the direction of arrival, zeroing, reconfiguring the beam, and correcting channel amplitude and phase errors.

Background technique

A nulling antenna is a form of smart antenna. The smart antenna is composed of many antenna radiating units, and each radiating unit is fed with a signal of a certain amplitude and phase (called amplitude weight and phase weight) to form a specific beam to realize beam scanning, enhancement or zeroing. Generally, the signal amplitude of the radiation unit is adjusted by controlling the amplitude regulator connected to the radiation unit to form the required beam, and the phase of the unit signal is controlled by changing the phase regulator connected to the unit to realize beam scanning.

When the smart antenna needs to perform beam enhancement or zero adjustment in a certain Direction of Arrival (DOA), the amplitude weight and phase weight of each radiating unit are adaptively calculated according to the direction of arrival, and then through control and each The weight network (amplitude adjuster and phase adjuster) connected to each radiating unit realizes the required amplitude and phase weights, and obtains beam enhancement or zeroing pattern in the desired direction. The current nulling antenna either performs zeroing on the incoming wave or enhances the incoming wave, and does not have the capability of both zeroing the incoming wave and performing beam enhancement or beam reconfiguration on the incoming wave. In addition, when the working frequency band of the antenna is above Ka, it is more difficult to implement a high-precision weight network (amplitude regulator and phase regulator).

There are two ways for the smart antenna to zero the incoming signal, one is a closed loop method, and the other is an open loop method. The closed-loop method does not need to know the direction of the incoming wave, and directly adjusts the incoming wave to zero through repeated iterations until the intensity of the incoming wave drops to a level that the system can tolerate. In the open-loop method, the direction of arrival of the incoming wave is first estimated, and then the zeroing weight in the direction of arrival is obtained according to the estimated direction to realize zeroing. Conformity is generally not considered during zero adjustment, and the pattern after zero adjustment has large fluctuations, which will lead to large changes in signal strength in the service area.

Due to the error between the amplitude and phase of each channel of the actual zeroing antenna, the performance of the zeroing antenna will be deteriorated. Therefore, it is necessary to correct the amplitude and phase errors of each channel of the nulling antenna. Error correction can be divided into two categories: internal correction and external correction. When the working frequency band of the antenna reaches above the Ka frequency band, due to the limitation of the antenna radiation unit and channel size, the internal correction method is difficult to realize, and the external correction method is generally used. In order to reduce the error caused by the calibration method itself, the external calibration method generally requires that the distance between the calibration antenna and the radiation unit be more than 200 wavelengths. When the space where the antenna is installed is limited, this requirement cannot be met, so the general external correction method is no longer applicable.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art, and provide a new zero-adjustment antenna. On the one hand, it reduces the difficulty of realizing a high-precision weight network, reduces the fluctuation of the pattern in the service area after zero-adjustment, and makes the external correction The method is no longer limited by space, on the other hand, the nulling antenna has the ability of direction of arrival estimation, zeroing and beam reconstruction at the same time, and further enhances the flexibility and anti-interference performance of the nulling antenna, which has wide applicability and promotion Value.

The above object of the present invention is mainly achieved through the following technical solutions: a zero-adjusting antenna, comprising an antenna array composed of N radiating elements, N down-converters, N couplers, (N+1)×M Switch matrix, signal orthogonalizer, A/D collector, processor, microwave weight network, beamforming network, synthesized signal coupler, calibration signal source, calibration antenna; the processor controls the working mode of the zeroing antenna, including Zeroing working mode, direction of arrival detection working mode, and beam on-orbit reconstruction working mode; among them:

In the zero-adjusting working mode: the antenna array composed of N radiating units receives external high-frequency microwave signals and sends them to N down-converters, and the N down-converters respectively convert the received high-frequency microwave signals into low-frequency microwave signals; N Each coupler divides the down-converted microwave signal into two parts, one part is input to the microwave weight network, and the other part is input to the first to Nth input ports of the (N+1)×M switch matrix; (N+1 )×M switch matrix selects the signals of M channels with interference from N channels and sends them to the signal orthogonalizer; the signal orthogonalizer orthogonalizes the signals of each of the M channels , form M pairs of I/Q signals, and transmit them to the A/D collector; A/D collector 6 collects the I/Q signals and sends them to the processor; the processor first estimates the direction of arrival of the interference signal, and then according to The estimated interference direction determines the zero-adjusted beamforming weight, and sends the beamforming weight minus the channel amplitude and phase distribution error to the microwave weight network; the microwave weight network weights the signal sent by the coupler in the microwave frequency band Send it to the beamforming network; the beamforming network superimposes the weighted microwave signal at its output port to form the desired zeroing beam, which is output through the through port of the synthetic signal coupler;

Direction of arrival detection working mode: the antenna array composed of N radiating units receives external high-frequency microwave signals; N down-converters convert high-frequency microwave signals into low-frequency microwave signals; N couplers convert frequency-converted microwave The signal is input to the (N+1)×M switch matrix; the (N+1)×M switch matrix selects the signals of M channels from the N channels, and sends them to the signal orthogonalizer; the signal orthogonalizer Orthogonalize the signals of each of the M channels to form M pairs of I/Q signals and transmit them to the A/D collector; the A/D collector collects the I/Q signals and sends them to the processor; The processor estimates the direction of arrival of the signal;

Beam on-orbit reconstruction mode: the antenna array composed of N radiating units receives external high-frequency microwave signals and outputs them to N down-converters; each down-converter converts high-frequency microwave signals into lower-frequency microwave signals ; N couplers respectively input the frequency-converted microwave signal to the microwave weight network; the processor sends the predetermined beam on-orbit reconstruction weight minus the channel amplitude and phase distribution error to the microwave weight network; the microwave weight network The signal sent by the coupler is weighted in the microwave frequency band and then sent to the beamforming network; the beamforming network superimposes the weighted signal at its output port to form the desired reconstructed beam, which is output through the through port of the synthesized signal coupler .

The determination of the channel amplitude and phase distribution error is obtained by selecting and entering the calibration mode by the processor, and the specific process is as follows:

The calibration signal source sends calibration signals to the array elements through the calibration antenna; the antenna array composed of N radiation elements receives the calibration signals and outputs them to N down-converters respectively; each down-converter converts the calibration signals into low-frequency microwave signals Output to the coupler; the coupler divides the frequency-converted microwave signal into two parts, one part is input to the 1st to Nth input ports of the (N+1)×M switch matrix; the other part is input to the microwave weight network, microwave The weight network sends this part of the signal to the beamforming network, and the beamforming network outputs the microwave signal to the composite signal coupler, and the composite signal coupler couples the composite signal through its coupling port to the (N+1)×M switch matrix The (N+1)th input port; the processor determines the relative amplitude and phase distribution of all channels relative to the coupled output signal of the first channel, and then calibrates the amplitude and phase errors caused by the position difference between the antenna and the N radiation elements , compensate and normalize the relative amplitude and phase distribution of 1 to N channels, and obtain the channel amplitude and phase distribution error.

The steps for the processor to determine the relative amplitude and phase distribution of all channels relative to the coupled output signal of the first channel in the calibration working mode are as follows:

In the first step, the processor first sets the microwave weight network of the first channel to the state of no attenuation and no phase shift, and sets the microwave weight network of other channels to the state of maximum attenuation;

In the second step, the (N+1)×M switch matrix sends the coupled output signal of the first channel as a reference signal and the coupled signal output by the synthesized signal coupler 12 to the signal orthogonalizer; The two-way signals are orthogonalized to form two pairs of I/Q signals and transmitted to the A/D collector; the A/D collector collects 2 pairs of I\Q signals and sends them to the processor; The two signals collected by the D collector are compared in amplitude and phase, and the relative amplitude and phase distribution of the first channel relative to the coupled output signal of the first channel is obtained;

In the third step, the processor then sequentially sets the microwave weight network of the 2nd to N channels to the state of no attenuation and no phase shift, and sets the microwave weight network of other channels to the state of maximum attenuation, (N+1)×M The switch matrix sends the coupled output signal of the first channel as a reference signal and the coupled signal output by the synthesized signal coupler to the signal orthogonalizer; the signal orthogonalizer orthogonalizes the two channels of signals to form two pairs of I /Q signal, and transmit it to the A/D collector; the A/D collector collects the I\Q signal and sends it to the processor; the processor compares the amplitude of the two signals collected by the A/D collector, respectively Obtain the relative amplitude and phase distribution of channels 2-N relative to the coupled output signal of the first channel.

Said N≥3, M≥3.

The low frequency band is microwave frequency band.

The microwave weight network works in the microwave frequency band.

The (N+1)×M switch matrix works in the microwave frequency band.

The direction-of-arrival estimation of the interference signal is realized by using a multiple signal classification algorithm.

The implementation algorithm for determining the zeroing beamforming weights in the zeroing working mode is as follows:

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&Delta;\&epsiv;</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; \{</span><span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; W</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; \}</span>\\ {\mathrm{<span\; class="notranslate">\; W</span>}}^{\mathrm{<span\; class="notranslate">\; h</span>}}\mathrm{<span\; class="notranslate">\; \&beta;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}\end{array}\right.$

Among them, W _q is the weight vector of the microwave weight network when there is no interference, also known as the static weight vector; vector; W ^H is the conjugate transpose matrix of W, △ε is the absolute value of the error between the weight vector W to be zeroed and the static weight vector W _q ; in the case of no interference, by changing the static weight vector, so that The signal received by the array forms the required pattern;

The W obtained by using the Lagrange multiplier method is the zeroing weight vector obtained based on the conformal (keeping W _q minimum change) design, represented by W _null , as:

W _null =(I-β(β ^H β) ^-1 β ^H )W _q

In the formula, I is a unitary matrix, and β ^H is the conjugate transpose matrix of β.

Compared with the prior art, the present invention has beneficial effects as follows:

(1) The scheme of down-converting high-frequency microwave signals to lower microwave frequency bands for beamforming proposed by the present invention not only ensures the radio frequency working bandwidth of the antenna, but also reduces the difficulty and complexity of weight network implementation (using the current The existing weight network implementation method is enough), and has higher weight realization accuracy;

(2) The external correction method of spatial amplitude and phase compensation proposed by the present invention makes the external correction method no longer limited by space, reduces the difficulty of realizing the high-frequency band external correction method and ensures the accuracy, and can be applied to smaller scales and The channel amplitude and phase error correction of space-constrained array antenna has wide applicability and application value;

(3) The present invention proposes a conformal zeroing scheme, which reduces the ups and downs of the direction diagram in the service area after zeroing, reduces the variation range of signal strength in the service area, and reduces the difficulty of realizing the signal link.

(4) The multiple working modes of direction of arrival estimation, nulling, and on-orbit beam reconstruction proposed by the present invention enable the nulling antenna to have greater flexibility and stronger anti-jamming capability.

Description of drawings

Fig. 1 is a block diagram of the present invention.

Detailed ways

Below in conjunction with accompanying drawing, antenna of the present invention is described in detail, as shown in Figure 1, specifically as follows:

1. Antenna Structure Introduction

The zeroing antenna includes: antenna array composed of N radiating elements 1, N down-converters 2, N couplers 3, (N+1)×M switch matrix 4, signal orthogonalizer 5, A/D Collector 6, processor 7, microwave weight network 8, beamforming network 9, composite signal coupler 12, calibration signal source 11, calibration antenna 10; above N≥3, M≥3. The processor 7 controls the working modes of the zeroing antenna, including the zeroing working mode, the direction of arrival detection working mode, the beam on-orbit reconstruction working mode and the calibration working mode; the specific implementation methods in each working mode are as follows:

1) In the zeroing mode, the antenna array 1 composed of N radiating units receives external high-frequency signals; N down-converters 2 convert high-frequency microwave signals into microwave signals of lower frequency (microwave frequency); N couplers 3 divide the down-converted microwave signal into two parts, one part is input to the microwave weight network 8, and the other part is input to the (N+1)×M switch matrix 4; (N+1)×M switch matrix 4 Select the signals of M channels with interference from the N channels, and send them to the signal orthogonalizer 5; the signal orthogonalizer 5 orthogonalizes the signals of each channel of the M channels to form M The I/Q signal is transmitted to the A/D collector 6; the A/D collector 6 collects the I/Q signal and sends it to the processor 7; the processor 7 utilizes multiple signal classification methods (Multiple Signal Classification, MUSIC ) to realize the estimation of the Direction of Arrival (DOA) of the interference signal; then according to the interference direction, the zeroing beamforming weight is calculated by using the conformal zeroing algorithm, and the beamforming weight is sent to the microwave weight network8 ; The microwave weight network 8 sends the signal sent by the coupler 3 to the beam forming network 9 after amplitude-phase weighting in the microwave frequency band; the beam forming network 9 superimposes the weighted microwave signals at its output port to form a desired zeroing beam , and output through the straight-through port of the synthesized signal coupler 12.

2) In the direction-of-arrival detection working mode, the antenna front 1 composed of N radiation units receives external signals; N down-converters 2 convert high-frequency microwave signals into lower-frequency microwave signals; N couplers 3 Input the frequency-converted microwave signal to (N+1)×M switch matrix 4; (N+1)×M switch matrix 4 selects the signals of M channels from N channels, and sends them to the signal orthogonalization Device 5; signal orthogonalizer 5 carries out orthogonalization to the signal of each channel of M channels, forms M pairs of I/Q signals, and transmits to A/D collector 6; A/D collector 6 pairs I After the \Q signal is collected, it is sent to the processor 7; the processor 7 uses the multiple signal classification method (Multiple Signal Classification, MUSIC) to realize the estimation of the signal direction of arrival (Direction of Arrival, DOA).

3) In the beam on-orbit reconstruction mode, the antenna array 1 composed of N radiating elements receives external signals; N down-converters 2 convert high-frequency microwave signals into lower-frequency microwave signals; N couplers 3. Input the frequency-converted microwave signal to the microwave weight network 8; the processor 7 sends the predetermined beam on-orbit reconstruction weight to the microwave weight network 8; the microwave weight network 8 sends the signal sent by the coupler 3 The weighted signal is sent to the beamforming network 9; the beamforming network 9 superimposes the weighted signals at its output port to form a desired reconstructed beam, and outputs it through the through port of the synthesized signal coupler 12.

4) In the calibration working mode, the calibration signal source 11 sends a calibration signal to the radiation unit through the calibration antenna 10; the antenna array 1 composed of N radiation units receives the calibration signal; N down-converters 2 convert the high-frequency calibration signal It is a microwave signal in a lower frequency band; N couplers 3 divide the frequency-converted microwave signal into two parts, one part is input to the first to Nth input ports of (N+1)×M switch matrix 4; the other part is input To the microwave weight network 8, the microwave weight network 8 sends this part of the signal to the beamforming network 9, and the beamforming network 9 outputs the microwave signal to the composite signal coupler 12, and the composite signal coupler 12 passes the composite signal through its coupling port A part of coupling output to the (N+1)th input port of (N+1)×M switch matrix 4; processor 7 according to the external correction algorithm of spatial amplitude and phase compensation, the position difference of the calibration antenna distance from N radiation elements The resulting amplitude and phase errors are compensated and normalized in the relative amplitude and phase distribution of 1 to N channels to obtain the real channel amplitude and phase distribution errors.

2. Algorithm introduction

1. The shape-preserving zeroing algorithm in the zeroing mode is as follows:

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&Delta;\&epsiv;</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; \{</span><span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; W</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; \}</span>\\ {\mathrm{<span\; class="notranslate">\; W</span>}}^{\mathrm{<span\; class="notranslate">\; h</span>}}\mathrm{<span\; class="notranslate">\; \&beta;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}\end{array}\right.$

Among them, W _q is the weight vector of the microwave weight network when there is no interference, also known as the static weight vector; vector; W ^H is the conjugate transpose matrix of W, △ε is the absolute value of the error between the weight vector W to be zeroed and the static weight vector W _q ; in the case of no interference, by changing the static weight vector, so that The signal received by the array forms the required pattern;

The W obtained by using the Lagrange multiplier method is the zeroing weight vector obtained based on the conformal (keeping W _q minimum change) design, represented by W _null , as:

W _null =(I-β(β ^H β) ^-1 β ^H )W _q

In the formula, I is a unitary matrix, and β ^H is the conjugate transpose matrix of β.

2. The external calibration algorithm of spatial amplitude and phase compensation in the calibration mode is as follows:

The distance between the calibration antenna and the antenna array (that is, the antenna array composed of N radiating elements) does not meet the condition of not less than 200 wavelengths required by the general external correction algorithm; the distance between the calibration antenna phase center and the radiating element phase center The physical distance is known accurately, which are respectively d _j (j=1～N), and the spatial amplitude and phase errors brought about by it are:

$\mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 20</span>}\mathrm{<span\; class="notranslate">\; log</span>}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}}{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 20</span>}\mathrm{<span\; class="notranslate">\; log</span>}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ~</span>\mathrm{<span\; class="notranslate">\; N</span>}$

以及第j个通道信号的实、虚部

计算出第j个通道信号相对于第1个通道的耦合器输出信号的幅度与相位差：Turn on the calibration signal source, set the weight amplitude and phase of the microwave weight network of the jth channel to 0 (that is, no attenuation and no phase shift), set the microwave weight network amplitude of other channels to the maximum attenuation or close, use The (N+1)×M switch matrix sends the coupled output signal of the first channel (as a reference signal) and the coupled signal output by the synthesized signal coupler to the signal orthogonalizer, and the first channel is obtained by the A/D collector The real and imaginary parts of the coupler output signal of the channel

And the real and imaginary parts of the jth channel signal

Calculate the amplitude and phase difference of the jth channel signal relative to the coupler output signal of the first channel:

${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>\sqrt{{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; I</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; Q</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$

${\mathrm{<span\; class="notranslate">\; \&phi;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arctg</span>}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; Q</span>}}}{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; I</span>}}}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; =</span>\sqrt{{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}^{\mathrm{<span\; class="notranslate">\; I</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}^{\mathrm{<span\; class="notranslate">\; Q</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ~</span>\mathrm{<span\; class="notranslate">\; N</span>}$

${\mathrm{<span\; class="notranslate">\; \&phi;</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arctg</span>}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}^{\mathrm{<span\; class="notranslate">\; Q</span>}}}{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}^{\mathrm{<span\; class="notranslate">\; I</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ~</span>\mathrm{<span\; class="notranslate">\; N</span>}$

ΔB _j =20log(B _j )-20log(B ₁ ) j=1～N

In the formula, B ₁ , φ ₁ , B _j , φ _j are the amplitude (in dB) and phase (in °) of the coupled output signal of the first channel and the coupled signal of the synthesized beam respectively; ΔB _j and Δφ _j are respectively is the magnitude and phase difference of the jth channel signal relative to the coupled output signal of the first channel.

Compensate the spatial amplitude and phase error caused by the physical distance between the phase center of the calibration antenna and the phase center of the radiation unit, and obtain the normalized amplitude and phase difference of each channel relative to the first channel. The algorithm is as follows:

ΔB _j—Nor =ΔB _j -ΔA _j j=1～N

式中，ΔB_j—Nor、Δφ_j—Nor、分别为第j个通道信号相对于第1个通道的归一化幅度与相位差。

In the formula, ΔB _j—Nor , Δφ _j—Nor , are the normalized amplitude and phase difference of the jth channel signal relative to the first channel, respectively.

Parts not described in detail in the present invention belong to the common knowledge of those skilled in the art.

Claims (9)

1. A zero-adjusting antenna, characterized in that it includes an antenna array composed of N radiation elements (1), N down-converters (2), N couplers (3), (N+1)×M Switch matrix (4), signal orthogonalizer (5), A/D collector (6), processor (7), microwave weight network (8), beamforming network (9), synthetic signal coupler ( 12), Calibrate the signal source (11), calibrate the antenna (10); the processor (7) controls the working mode of the zeroing antenna, including the zeroing working mode, the direction of arrival detection working mode, and the beam on-orbit reconstruction working mode; in: In the zeroing working mode: the antenna array (1) composed of N radiating units receives external high-frequency microwave signals and transmits them to N down-converters (2), and the N down-converters (2) respectively transmit the received high-frequency microwave signals to The signal is converted into a low-frequency microwave signal; N couplers (3) respectively divide the down-converted microwave signal into two parts, one part is input to the microwave weight network (8), and the other part is input to the (N+1)×M switch The 1st to Nth input ports of matrix (4); (N+1)×M switch matrix (4) selects the signals of M channels with interference from N channels, and sends them to signal orthogonalization device (5); the signal orthogonalizer (5) orthogonalizes the signals of each of the M channels to form M pairs of I/Q signals, and transmits them to the A/D collector (6); A/D The D collector (6) collects the I/Q signal and sends it to the processor (7); the processor (7) first estimates the direction of arrival of the interference signal, and then determines the zeroing beamforming weight according to the estimated interference direction, And send the beamforming weight to the microwave weight network (8) after subtracting the channel amplitude and phase distribution error; the microwave weight network (8) weights the signal sent by the coupler (3) in the microwave frequency band and sends it to the beam Synthesis network (9); the beam synthesis network (9) superimposes the weighted microwave signals at its output port to form a desired zero-adjustment beam, and the beam is output through the through port of the synthesis signal coupler (12); Direction of arrival detection working mode: Antenna array composed of N radiating elements (1) receives external high-frequency microwave signals; N down-converters (2) transform high-frequency microwave signals into low-frequency microwave signals; N coupling The converter (3) inputs the frequency-converted microwave signal to the (N+1)×M switch matrix (4); the (N+1)×M switch matrix (4) selects the signals of M channels from the N channels, Send it to the signal orthogonalizer (5); the signal orthogonalizer (5) orthogonalizes the signals of each of the M channels to form M pairs of I/Q signals and transmit them to the A/D The collector (6); the A/D collector 6 collects the I\Q signal and sends it to the processor (7); the processor (7) estimates the direction of arrival of the signal; Beam on-orbit reconstruction working mode: the antenna array (1) composed of N radiating elements receives external high-frequency microwave signals and outputs them to N down-converters (2); each down-converter (2) converts high-frequency microwave The signal is converted into a microwave signal of a lower frequency band; N couplers (3) respectively input the frequency-converted microwave signal to the microwave weight network (8); the processor (7) reconstructs the predetermined beam on-orbit weight The channel amplitude and phase distribution error is subtracted and sent to the microwave weight network (8); the microwave weight network (8) weights the signal sent by the coupler (3) in the microwave frequency band and sends it to the beamforming network (9); The synthesizing network (9) superimposes the weighted signals at its output port to form a desired reconstructed beam, and the beam is output through the through port of the synthesizing signal coupler (12). 2. A zero-adjusting antenna according to claim 1, characterized in that: the determination of the channel amplitude and phase distribution error is obtained through the selection of the processor (7) to enter the calibration working mode, and the specific process is as follows: The calibration signal source (11) sends calibration signals to the array elements through the calibration antenna (10); the antenna array (1) composed of N radiation elements receives the calibration signals and outputs them to N down-converters (2); each down-converter The converter (2) converts the calibration signal into a low-frequency microwave signal and outputs it to the coupler (3); the coupler (3) divides the frequency-converted microwave signal into two parts, and one part is input to the (N+1)×M switch The first to Nth input ports of the matrix (4); the other part is input to the microwave weight network (8), and the microwave weight network (8) sends this part of the signal to the beamforming network (9), and the beamforming network ( 9) Output the microwave signal to the composite signal coupler (12), and the composite signal coupler (12) couples the composite signal through its coupling port to the (N+1)th (N+1) of the (N+1)×M switch matrix 4 Input port; the processor (7) determines the relative amplitude and phase distribution of all channels relative to the coupled output signal of the first channel, and then adjusts the amplitude and phase errors caused by the position difference between the calibration antenna and the N radiation elements in the range of 1~ The relative amplitude and phase distributions of N channels are compensated and normalized to obtain channel amplitude and phase distribution errors. 3. A zero-adjusting antenna according to claim 2, characterized in that: the step of the processor (7) determining the relative amplitude and phase distribution of all channels relative to the coupled output signal of the first channel in the calibration working mode as follows: In the first step, the processor (7) first sets the microwave weight network of the first channel to a no-attenuation and no-phase-shift state, and sets the microwave weight network of other channels to a maximum attenuation state; In the second step, the (N+1)×M switch matrix (4) sends the coupled output signal of the first channel as a reference signal and the coupled signal output by the synthesized signal coupler (12) to the signal orthogonalizer (5) ; The signal orthogonalizer (5) orthogonalizes the two channels of signals to form two pairs of I/Q signals, and transmits them to the A/D collector (6); the A/D collector (6) pairs 2 pairs The I\Q signal is collected and sent to the processor (7); the processor (7) compares the amplitude of the two signals collected by the A/D collector (6), and obtains the first channel relative to the first channel The relative amplitude and phase distribution of the coupled output signal; In the third step, the processor (7) then sequentially sets the microwave weight network of the 2nd to N channels to the state of no attenuation and no phase shift, and sets the microwave weight network of other channels to the state of maximum attenuation, (N+1 )×M switch matrix (4) sends the coupled output signal of the first channel as a reference signal and the coupled signal output by the synthesized signal coupler (12) to the signal orthogonalizer (5); the signal orthogonalizer (5 ) Orthogonalize the two channels of signals to form two pairs of I/Q signals, and transmit them to the A/D collector (6); A/D collector 2 collects the I\Q signals and sends them to the processor ( 7); the processor (7) compares the amplitude and phase of the two signals collected by the A/D collector (6), and respectively obtains the relative amplitude and phase distributions of channels 2 to N relative to the coupled output signal of the first channel. 4. The zeroing antenna according to claim 1, characterized in that: said N≥3, M≥3. 5. The zeroing antenna according to claim 1, wherein the low frequency band is a microwave frequency band. 6. The zeroing antenna according to claim 1, characterized in that the microwave weight network (8) works in the microwave frequency band. 7. The zeroing antenna according to claim 1, characterized in that: the (N+1)×M switch matrix (4) works in the microwave frequency band. 8 . The zeroing antenna according to claim 1 , wherein the estimation of the direction of arrival of the interference signal is realized by using a multiple signal classification algorithm. 9. The zeroing antenna according to claim 1, characterized in that: the implementation algorithm for determining the zeroing beamforming weights in the zeroing working mode is as follows: $\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&Delta;\&epsiv;</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; \{</span><span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; W</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}<span\; class="notranslate">\; |</span><span\; class="notranslate">\; \}</span>\\ {\mathrm{<span\; class="notranslate">\; W</span>}}^{\mathrm{<span\; class="notranslate">\; h</span>}}\mathrm{<span\; class="notranslate">\; \&beta;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}\end{array}\right.$ Among them, W _q is the weight vector of the microwave weight network when there is no interference, also known as the static weight vector; vector; W ^H is the conjugate transpose matrix of W, Δε is the absolute value of the error between the weight vector W to be zeroed and the static weight vector W _q ; in the case of no interference, by changing the static weight vector, the array The received signal forms the required pattern; The W obtained by using the Lagrange multiplier method is the zeroing weight vector obtained based on the conformal (keeping W _q minimum change) design, represented by W _null , as: W _null =(I-β(β ^H β) ^-1 β ^H )W _q In the formula, I is a unitary matrix, and β ^H is the conjugate transpose matrix of β.