RF injection simulation method for phased array radar based on equivalent inversion of antenna performance

Abstract

The present invention relates to the technical field of radio frequency injection simulation of radar equipment, and discloses a radio frequency injection simulation method for phased array radar based on equivalent inversion of antenna performance. The system adopted by the method includes: a host, an I / O interface adapter unit, and a display control unit. The baseband signal generation unit of the host is connected to the antenna beam forming unit through a baseband signal modulation unit, and the output end of the antenna beam forming unit is connected to the up-conversion input end of the up / down conversion unit through a baseband signal synthesis unit. The up-conversion output end of the up / down conversion unit is connected to the radar under test through a cable. The down-conversion input end of the up / down conversion unit is connected to the excitation end of the radar under test through a cable. The present invention can significantly reduce the number of radio frequency feeding channels required for the simulation system, significantly improve the flexibility of the signal simulation function of the simulation system, enhance the versatility and applicability of the system; improve the application space of simulation technology, and help give full play to the advantages of simulation technology and improve the test cost-effectiveness.

Description

Technical Field

[0001] The present invention relates to the technical field of radio frequency injection simulation of radar equipment, and in particular to a radio frequency injection simulation method for phased array radar based on equivalent inversion of antenna performance. Background Art

[0002] The basic principle of RF injection simulation testing of radar equipment is that the simulation system generates complex electromagnetic environment signals, including radar targets, clutter, and interference, based on combat scenarios. These signals are then injected into the radar receiver via a line feed. Radar performance is then verified and evaluated by observing and analyzing the radar's target search, interception, identification, and tracking. During testing, the port between the radar antenna and receiver is disconnected, and the signal is injected through the radar receiver port. The actual radar antenna is not involved in the simulation test loop. Therefore, the simulation system must simulate the radar antenna's beamforming function and construct an equal number of RF feed channels as the radar antenna's feed receive channels (e.g., sum branch, azimuth difference branch, elevation difference branch, etc.) to simulate the output signals of each antenna channel.

[0003] From the perspective of equipment performance testing, the signal injection port should be located as close as possible to the radar's receiving antenna port, allowing as many links in the radar's receiving channel as possible to participate in the simulation test loop, fully assessing the radar's signal reception and processing capabilities. For phased array radars, the ideal signal injection port is the receiving branch port of the phased array antenna's T / R assembly. However, the number of radiating elements in a phased array radar antenna typically reaches thousands or even tens of thousands. If signal injection is used from the antenna unit port, the simulation system must establish a separate RF feed channel for each antenna element, resulting in a large, complex, and costly simulation system. This directly limits the application and advantages of simulation technology in phased array radar performance testing. Therefore, a technical approach must be found to effectively reduce the number of RF channels in the simulation system, reduce the difficulty and cost of system design and implementation, enhance the flexibility of injection-based simulation of phased array radars, and improve the application of simulation technology in phased array radar performance testing.

[0004] Currently, there are two main approaches to implementing RF injection simulation testing for phased array radars using RF beamforming technology:

[0005] First, the radar receiver port after the antenna beamforming network is selected as the signal injection port. The simulation system can only simulate and generate radar echo signals for the corresponding receiving channel according to the radar receiving beam formed by the antenna beamforming network (such as the sum and difference beams). This method is characterized by a small number of simulation system channels and relatively simple technical implementation. However, it is difficult to evaluate the performance of the radar antenna feed channel and beamforming unit. The simulation system has poor versatility and applicability, and its application scenarios are limited.

[0006] Second, the antenna unit's T / R component receiving branch port is selected as the signal injection port, and the simulation system simulates the radar echo signal received by each antenna unit's feed channel. This feature can assess the performance of the array antenna unit's receiving link. The simulation system is versatile and highly applicable, but the system requires a large number of channels, is complex to implement, and has high development costs.

[0007] Both of the above solutions have certain technical limitations, which restrict the advantages of simulation technology and its application in the field of phased array radar performance testing. In addition, the simulation system built based on the above route has poor versatility and great application limitations.

[0008] References

[0009] 1. Zhang Guangyi, Zhao Yujie. Phased Array Radar Technology [M]. Beijing: Electronics Industry Press, 2006. 2. Zhang Guangyi. Phased Array Radar System [M]. Beijing: National Defense Industry Press, 1997.

[0010] 3. Ding Lufei, Geng Fulu, Chen Jianchun, et al. Principles of Radar (5th Edition)[M]. Beijing: Publishing House of Electronics Industry, 2014. Summary of the Invention

[0011] In order to overcome the shortcomings of the existing technology, the present invention proposes a phased array radar radio frequency injection simulation method based on antenna performance equivalent inversion.

[0012] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0013] A phased array radar RF injection simulation method based on antenna performance equivalent inversion is based on the antenna beam synthesis principle of the phased array radar. That is, based on the original radar array antenna receiving beam pattern, the radar antenna array surface is divided into sub-arrays by inverse design. By designing the comprehensive factors of each sub-array, the antenna beam pattern after weighted synthesis of each sub-array is made consistent with the original radar antenna receiving beam pattern. The simulation system only needs to simulate and generate the radar echo signal synthesized by each sub-array according to the divided sub-array and inject it into the radar under test. The method includes: a phased array radar antenna beam equivalent simulation method and a phased array radar echo signal equivalent simulation generation method.

[0014] (1) The antenna of a phased array radar consists of multiple antenna radiating elements and a signal power distribution / addition network arranged in a regular pattern on a plane or arbitrary curved surface. The beam direction and beam shape are changed by controlling and changing the phase offset and amplitude weighting value of the received signal of each array element to achieve beam scanning.

[0015] Assume a planar phased array antenna consisting of M×N antenna elements. The antenna elements are arranged in a rectangular grid along the zoy plane in M ​​rows and N columns. The spacing between rows and columns is d1 and d2 respectively. Under the condition that the effect of the spatial transmission path difference on the signal amplitude of each antenna element is ignored, a point in the far area of ​​space is The antenna pattern function at is expressed as:

[0016]

[0017] in, ——Element factor (antenna unit pattern);

[0018] ——array synthesis factor;

[0019] λ——operating wavelength;

[0020] d1, d2——the spacing between the row and column elements of the array antenna;

[0021] α, β - the excitation phase difference between antenna elements in the antenna array along the y-axis (horizontal) and z-axis (vertical), also known as the "intra-array phase difference";

[0022] a ik ——The amplitude weighting coefficient of the (i,k)th antenna element is a ik .

[0023] (2) The phased array antenna is divided into sub-arrays. Several units on the array surface are regarded as a whole, and as a basic unit of the phased array antenna is called a sub-array. Then, a signal feeding and receiving channel is designed for each sub-array. Its feeding and receiving network is regarded as a two-layer network, or more than two-layer network. One layer is the sub-array adding network, which mainly performs power synthesis on the receiving signals of each antenna array element in the sub-array; the other layer is the beam forming network, which mainly performs weighting on the output signals of each sub-array to obtain the desired beam.

[0024] By using a phased array antenna that has been divided into subarrays, each subarray can be regarded as an antenna unit, and the entire array antenna can be regarded as being composed of subarrays arranged according to a certain pattern. At this time, when analyzing the antenna radiation pattern of the entire array antenna, it is only necessary to use the subarray factor synthesis radiation pattern instead of the array element factor antenna unit radiation pattern, and use the subarray synthesis factor instead of the array synthesis factor.

[0025] Assume that the planar phased array antenna contains M×N antenna elements, and the entire array is divided into P×Q sub-arrays. Each sub-array contains L×S antenna elements. Each antenna element in the sub-array is fed with equal amplitude. Under the condition of ignoring the influence of the spatial transmission path difference on the signal amplitude of each antenna element, a point in the far area of ​​space is The antenna pattern function at is expressed as:

[0026]

[0027] in, ——Element factor, that is, the antenna element pattern;

[0028] ——subarray factor;

[0029] ——Subarray comprehensive factor;

[0030] λ——operating wavelength;

[0031] α, β—the excitation phase difference between antenna elements along the y-axis (horizontal) and z-axis (vertical) within the antenna array—the phase difference within the array;

[0032] d1, d2——the spacing between the row and column elements of the array antenna;

[0033] b ik ——the amplitude weighting coefficient of the (i,k)th antenna element of the subarray;

[0034] c ht ——the amplitude weighting coefficient of the (h,t)th sub-matrix;

[0035] The sub-array design reduces the number of array antenna feed channels, but since the antenna aperture and the number of antenna units have not been reduced, the synthesized antenna gain, beam width, etc. will remain unchanged.

[0036] For phased array radars using RF beamforming technology, the implementation steps are as follows:

[0037] (1) Divide the radar array antenna into M sub-arrays, M ≥ 1, and each sub-array contains N antenna elements;

[0038] (2) Arbitrarily select the feeding receiving channels corresponding to M antenna units as the signal injection channels during the simulation test, and the corresponding weighting coefficients are recorded as a1, a2, ..., a M ;

[0039] (3) For each sub-array, use the weighting factor of the N antenna elements corresponding to each sub-array, denoted as a i1 ,a i2 ,…,a iN , i=1,2,…M, calculate the composite directional pattern of M sub-arrays, denoted as f i1 , f i2 ,…,f iM , i=1,2,…M;

[0040] (4) Considering the weighting factors a1, a2, ..., a corresponding to the M signal injection channels selected during the test, M It is still valid, that is, the injected signal will still be weighted. Therefore, the composite pattern of each sub-array needs to be reversely corrected to offset its influence. The composite pattern of each sub-array after correction is f1 / a1, f2 / a2,…, f M / a M ;

[0041] (5) Using the modified sub-array synthetic pattern and the spatial relative position relationship between the radar and the target, the radar echo signals r1(t), r2(t),…, r1(t) output by each sub-array are calculated. M (t), which is the radar echo signal that the simulation system needs to simulate.

[0042] A phased array radar radio frequency injection simulation system, comprising: a host, an I / O interface adapter unit, and a display control unit. The host interface end is connected to the data end of the radar under test through the I / O interface adapter unit, the host display end is connected to the display control unit through a cable, and the host output end is connected to the input end of the radar under test through a cable; the host includes: a baseband signal generation unit, a baseband signal modulation unit, an antenna beam forming unit, a baseband signal synthesis unit, an up / down conversion unit, and a clock and local oscillator unit. The input end of the baseband signal generation unit is connected to the up / down conversion unit through a cable. The output end of the baseband signal generation unit is connected to the input end of the antenna beam forming unit through the baseband signal modulation unit. The output end of the antenna beam forming unit is connected to the up-conversion input end of the up / down conversion unit through the baseband signal synthesis unit. The up-conversion output end of the up / down conversion unit is connected to the input end of the radar under test through a cable. The down-conversion input end of the up / down conversion unit is connected to the output excitation end of the radar under test through a cable. The oscillation end of the up / down conversion unit is connected to the clock and local oscillator unit. The input end of the clock and local oscillator unit is connected to the output reference signal end of the radar under test through a cable. The output end of the clock and local oscillator unit is the clock signal output end.

[0043] A phased array radar radio frequency injection simulation system, wherein a baseband signal generation unit is composed of a target echo simulation circuit, a clutter signal simulation circuit, an interference signal simulation circuit and an A / D module electrically connected, an A / D module input end is connected to an up / down conversion unit, an A / D module output end is connected to one end of the target echo simulation circuit, the clutter signal simulation circuit and the interference signal simulation circuit, and the other ends of the target echo simulation circuit, the clutter signal simulation circuit and the interference signal simulation circuit are respectively the output ends of the baseband signal generation unit.

[0044] A phased array radar radio frequency injection simulation system, wherein a baseband signal modulation unit is electrically connected and composed of an atmospheric absorption effect simulation circuit, a multipath effect simulation circuit, a weather attenuation simulation circuit, a Doppler frequency shift simulation circuit, and a range delay simulation circuit; the input / output ends of the baseband signal modulation unit are respectively provided with a target echo signal end, a clutter signal end, and an interference signal end.

[0045] A phased array radar radio frequency injection simulation system, wherein an antenna beamforming unit is electrically connected to form an antenna scanning simulation circuit, a subarray pattern simulation circuit, a subarray weighting simulation circuit, and a subarray synthesis simulation circuit. The input end of the antenna beamforming unit is provided with a target echo signal end, a clutter signal end, and an interference signal end. The output end of the antenna beamforming unit is respectively provided with a target echo end, a clutter signal end, and an interference signal end of subarray 1, and a target echo end, a clutter signal end, and an interference signal end of subarray N.

[0046] A phased array radar RF injection simulation system, wherein the baseband signal synthesis unit is composed of a subarray 1 signal synthesis and D / A module connected in series to a subarray N signal synthesis and D / A module connected in series. The subarray 1 signal end to the subarray N signal end are the multi-channel input ends of the baseband signal synthesis unit, and the subarray 1 D / A module end to the subarray N D / A module end are the multi-channel output ends of the baseband signal synthesis unit.

[0047] A phased array radar radio frequency injection simulation system, wherein the up / down conversion unit is composed of a plurality of up conversion circuits and down conversion circuits electrically connected, the up conversion circuit is composed of an up conversion module and an amplifier connected in series, and the down conversion circuit is composed of a down conversion module and an amplifier connected in series.

[0048] Due to the adoption of the above technical solution, the present invention has the following advantages:

[0049] The present invention proposes a phased array radar RF injection simulation method based on equivalent antenna performance inversion, including a phased array radar antenna beam equivalent simulation method and a phased array radar echo signal equivalent simulation generation method. The phased array radar RF injection simulation system constructed based on these methods is advanced and economical, with strong functional reconfigurability, high versatility, and strong applicability. Compared with existing technical solutions, it has the following advantages:

[0050] First, it can significantly reduce the number of RF feed channels required for the simulation system, greatly compress the system hardware scale, and significantly reduce the difficulty and construction cost of technical implementation such as system multi-channel synchronization and amplitude and phase consistency assurance;

[0051] Second, it can greatly improve the flexibility of the simulation system's signal simulation function and enhance the system's versatility and applicability;

[0052] Third, it can significantly enhance the flexibility of phased array radar RF injection simulation and expand the application space of simulation technology, which is conducive to giving full play to the advantages of simulation technology, expanding equipment testing methods and means, and improving testing cost-effectiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 Schematic diagram of the phased array radar receiving feed network;

[0054] Figure 2 Schematic diagram of the receiving and feeding network of a phased array radar using a sub-array design;

[0055] Figure 3 Schematic diagram of a planar phased array antenna;

[0056] Figure 4 Schematic diagram of the phased array radar RF injection simulation system architecture. DETAILED DESCRIPTION

[0057] like Figure 1 、 2 As shown in Figures 3 and 4, a RF injection simulation method for phased array radar based on the technical principle of equivalent inversion of antenna performance is proposed. Its design is derived from the antenna beam synthesis technology of phased array radar, that is, based on the original radar array antenna receiving beam pattern, the radar antenna array surface is divided into sub-arrays using reverse design thinking. By reasonably designing the comprehensive factors of each sub-array, the antenna beam pattern after weighted synthesis of each sub-array is kept consistent with the original radar antenna receiving beam pattern. The simulation system only needs to simulate the generated radar echo signals output by each sub-array according to the divided sub-arrays and inject them into the radar under test. The composition and functions of the present invention include:

[0058] Phased array antennas are composed of multiple antenna units (radiating units) arranged in a certain pattern on a plane or an arbitrary curved surface and a signal power distribution / addition network. By controlling and changing the phase offset and amplitude weighting value of the received signal of each array element, the beam direction and beam shape are changed to achieve beam scanning. Figure 1 shown.

[0059] The basic idea of ​​dividing the phased array antenna into sub-arrays is to treat several units on the array surface as a whole, as a basic unit of the phased array antenna (called a sub-array), and then design a signal feeding and receiving channel for each sub-array to reduce the number of feeding channels. The feeding and receiving network can be regarded as a two-layer network, or more than two-layer network. One layer is the sub-array adding network, which mainly performs power synthesis on the received signals of each antenna array element in the sub-array; the other layer is the beam forming network, which mainly performs weighting on the output signals of each sub-array to obtain the desired beam. Figure 2 shown.

[0060] like Figure 3As shown in the figure, there is a planar phased array antenna containing M×N antenna elements. The antenna elements are arranged in an equidistant rectangular grid along the zoy plane, with M rows and N columns. The row and column element spacings are d1 and d2 respectively. Under the condition that the effect of the spatial transmission path difference on the signal amplitude of each antenna element is ignored, a point in the far area of ​​space The antenna pattern function at can be expressed as:

[0061]

[0062] in, ——Element factor (antenna unit pattern);

[0063] ——array synthesis factor;

[0064] λ——operating wavelength;

[0065] d1, d2——the spacing between the row and column elements of the array antenna;

[0066] α, β - the excitation phase difference between antenna elements in the antenna array along the y-axis (horizontal) and z-axis (vertical), also known as the "intra-array phase difference";

[0067] a ik ——The amplitude weighting coefficient of the (i,k)th antenna element is a ik .

[0068] After implementing subarray division, each subarray can be considered equivalent to an antenna unit, and the entire array antenna can be considered equivalent to being composed of subarrays arranged according to a certain pattern. In this case, when analyzing the antenna pattern of the entire array antenna, the element factor (antenna unit pattern) can be replaced by the subarray composite pattern (subarray factor), and the array composite factor can be replaced by the subarray composite factor.

[0069] Still taking the above-mentioned planar phased array antenna containing M×N antenna elements as an example, assume that the entire array surface is divided into P×Q sub-arrays, each sub-array contains L×S antenna elements, and each antenna element in the sub-array is fed with equal amplitude. Under the condition of ignoring the influence of the spatial transmission path difference on the signal amplitude of each antenna element, a certain point in the far area of ​​space is The antenna pattern function at can be expressed as:

[0070]

[0071] in, ——Element factor (antenna element pattern);

[0072] ——subarray factor;

[0073] ——Subarray comprehensive factor;

[0074] λ——operating wavelength;

[0075] α, β—the excitation phase difference between antenna elements in the antenna array along the y-axis (horizontal) and z-axis (vertical) directions (intra-array phase difference);

[0076] d1, d2——the spacing between the row and column elements of the array antenna;

[0077] b ik ——the amplitude weighting coefficient of the (i,k)th antenna element of the subarray;

[0078] c ht ——Amplitude weighting coefficient of the (h,t)th sub-matrix.

[0079] The sub-array design reduces the number of array antenna feed channels, but since the antenna aperture and the number of antenna units have not been reduced, the synthesized antenna gain, beam width, etc. will remain unchanged.

[0080] For a phased array radar using radio frequency beamforming technology, taking any antenna beam, such as the sum beam in the sum and difference beam, as an example, the implementation steps of the present invention are as follows:

[0081] 1) Divide the radar array antenna into M (M ≥ 1) sub-arrays, each sub-array contains N antenna elements;

[0082] 2) Arbitrarily select the feeding receiving channels corresponding to M antenna units as the signal injection channels during the simulation test, and the corresponding weighting coefficients are recorded as a1, a2, ..., a M ;

[0083] 3) For each sub-array, use the weighting factors (denoted as a) of the N antenna elements in each sub-array. i1 ,a i2 ,…,a iN , i=1,2,…M), calculate the composite directional pattern of M sub-arrays, denoted as f i1 , f i2 ,…,f iM , i=1,2,…M;

[0084] 4) Considering the weighting factors a1, a2, ..., a corresponding to the M signal injection channels selected during the test M It is still valid (i.e., the injected signal will still be weighted). Therefore, the composite pattern of each sub-array needs to be reversely corrected to offset its influence. The composite pattern of each sub-array after correction is f1 / a1, f2 / a2,…, f M / a M ;

[0085] 5) Using the modified sub-array synthetic pattern and the spatial relative position relationship between the radar and the target, the radar echo signals r1(t), r2(t), ..., r M (t), which is the radar echo signal that the simulation system needs to simulate.

[0086] like Figure 4 As shown, a phased array radar RF injection simulation system constructed based on the phased array radar RF injection simulation method for antenna performance equivalent inversion proposed by the present invention includes: a host, an I / O interface adapter unit, and a display control unit. The host interface end is connected to the data end of the radar under test through the I / O interface adapter unit, the host display end is connected to the display control unit through a cable, and the host output end is connected to the input end of the radar under test through a cable; the host includes: a baseband signal generating unit, a baseband signal modulating unit, an antenna beam forming unit, a baseband signal synthesizing unit, an up / down frequency conversion unit, a clock and local oscillator unit, and the input end of the baseband signal generating unit is connected to the input end of the radar under test through a cable. The up / down conversion unit is connected to the up / down conversion unit through a cable, the output end of the baseband signal generating unit is connected to the input end of the antenna beam forming unit through the baseband signal modulating unit, the output end of the antenna beam forming unit is connected to the up conversion input end of the up / down conversion unit through the baseband signal synthesizing unit, the up conversion output end of the up / down conversion unit is connected to the input end of the radar under test through a cable, and the down conversion input end of the up / down conversion unit is connected to the output excitation end of the radar under test through a cable; the oscillation end of the up / down conversion unit is connected to the clock and local oscillator unit, and the input end of the clock and local oscillator unit is connected to the output reference signal end of the radar under test through a cable; the output end of the clock and local oscillator unit is the output end of the clock signal.

[0087] The baseband signal generation unit is composed of a target echo simulation circuit, a clutter signal simulation circuit, an interference signal simulation circuit and an A / D module electrically connected. The input end of the A / D module is connected to the up / down conversion unit, and the output end of the A / D module is connected to one end of the target echo simulation circuit, the clutter signal simulation circuit and the interference signal simulation circuit. The other ends of the target echo simulation circuit, the clutter signal simulation circuit and the interference signal simulation circuit are respectively the output ends of the baseband signal generation unit.

[0088] The baseband signal modulation unit is composed of an atmospheric absorption effect simulation circuit, a multipath effect simulation circuit, a weather attenuation simulation circuit, a Doppler frequency shift simulation circuit, and a distance delay simulation circuit electrically connected. The input / output ends of the baseband signal modulation unit are respectively provided with a target echo signal end, a clutter signal end, and an interference signal end.

[0089] The antenna beamforming unit is composed of an antenna scanning analog circuit, a subarray pattern analog circuit, a subarray weighting analog circuit, and a subarray synthesis analog circuit electrically connected. The input end of the antenna beamforming unit is provided with a target echo signal end, a clutter signal end, and an interference signal end. The output end of the antenna beamforming unit is respectively provided with a target echo end, a clutter signal end, and an interference signal end of subarray 1, and a target echo end, a clutter signal end, and an interference signal end of subarray N.

[0090] The baseband signal synthesis unit is composed of a sub-array 1 signal synthesis and D / A module connected in series to a sub-array N signal synthesis and D / A module connected in series. The sub-array 1 signal end to the sub-array N signal end are the multi-way input ends of the baseband signal synthesis unit, and the sub-array 1 D / A module end to the sub-array N D / A module end are the multi-way output ends of the baseband signal synthesis unit.

[0091] The up / down conversion unit is composed of several up conversion circuits and down conversion circuits electrically connected. The up conversion circuit is composed of an up conversion module and an amplifier connected in series, and the down conversion circuit is composed of a down conversion module and an amplifier connected in series.

Claims

1. A phased array radar RF injection simulation method based on antenna performance equivalent inversion, characterized by: Based on the antenna beam synthesis principle of phased array radar, that is, based on the original radar array antenna receiving beam pattern, the radar antenna array is divided into sub-arrays by inverse design. By designing the comprehensive factors of each sub-array, the antenna beam pattern after weighted synthesis of each sub-array is made consistent with the original radar antenna receiving beam pattern. The simulation system only needs to simulate and generate the radar echo signal output by each sub-array according to the divided sub-array and inject it into the radar under test; including: phased array radar antenna beam equivalent simulation method and phased array radar echo signal equivalent simulation generation method; (1) The antenna of a phased array radar consists of multiple antenna radiating elements regularly arranged on a plane or arbitrary curved surface and a signal power distribution / addition network. The beam direction and beam shape are changed by controlling and changing the phase offset and amplitude weighting value of the received signal of each array element to achieve beam scanning; A planar phased array antenna consists of M×N antenna elements. The antenna elements are arranged in an equidistant rectangular grid along the zoy plane, with M rows and N columns. The spacing between rows and columns is d1 and d2 respectively. Under the condition that the effect of the spatial transmission path difference on the signal amplitude of each antenna element is ignored, a point in the far area of ​​space The antenna pattern function at is expressed as: in, Element factor – antenna unit pattern; ——array synthesis factor; λ——operating wavelength; d1, d2 - the spacing between the row and column elements of the array antenna; α, β - the excitation phase difference between each antenna element in the antenna array along the y-axis (horizontal) and the z-axis (vertical), also known as the "intra-array phase difference"; a ik ——The amplitude weighting coefficient of the (i,k)th antenna element is a ik ; (2) Divide the array antenna into subarrays, and treat several units on the array surface as a whole, as a basic unit of the phased array antenna, called a subarray. Then, design a signal feeding and receiving channel for each subarray. Its feeding and receiving network is regarded as a two-layer network, or more than two-layer network. One layer is the subarray adding network, which is used to synthesize the power of the received signals of each antenna array element in the subarray; the other layer is the beamforming network, which is used to weight the output signals of each subarray to obtain the desired beam. After adopting subarray division, each subarray is equivalent to an antenna unit, and the entire array antenna is equivalently composed of the subarrays arranged in a regular pattern. In this case, when analyzing the antenna pattern of the entire array antenna, it is only necessary to use the subarray factor composite pattern instead of the array element factor antenna pattern, and use the subarray composite factor instead of the array composite factor. Assume that the planar phased array antenna contains M×N antenna elements, and the entire array is divided into P×Q sub-arrays. Each sub-array contains L×S antenna elements. Each antenna element in the sub-array is fed with equal amplitude. Under the condition of ignoring the influence of the spatial transmission path difference on the signal amplitude of each antenna element, a point in the far area of ​​space is The antenna pattern function at is expressed as: in, ——The element factor is the antenna element pattern; ——subarray factor; ——Subarray comprehensive factor; λ——operating wavelength; α, β—the excitation phase difference between antenna elements along the y-axis (horizontal) and z-axis (vertical) within the antenna array—the phase difference within the array; d1, d2 - the spacing between the row and column elements of the array antenna; b ik ——the amplitude weighting coefficient of the (i,k)th antenna element of the subarray; c ht ——the amplitude weighting coefficient of the (h,t)th sub-matrix; For phased array radars using RF beamforming technology, the implementation steps are as follows: (1) Divide the radar array antenna into M sub-arrays, M ≥ 1, and each sub-array contains N antenna elements; (2) Arbitrarily select the feeding receiving channels corresponding to M antenna units as the signal injection channels during the simulation test, and the corresponding weighting coefficients are recorded as a1, a2, ..., a M ; (3) For each sub-array, use the weighting factor of the N antenna elements corresponding to each sub-array, denoted as a i1 ,a i2 ,…,a iN , i=1,2,…M, calculate the composite directional pattern of M sub-arrays, denoted as f i1 , f i2 ,…,f iM , i=1,2,…M; (4) Considering the weighting factors a1, a2, ..., a corresponding to the M signal injection channels selected during the test, M It is still valid, that is, the injected signal will still be weighted. Therefore, the composite pattern of each sub-array needs to be reversely corrected to offset its influence. The composite pattern of each sub-array after correction is f1 / a1, f2 / a2,…, f M / a M ; (5) Using the modified sub-array synthetic pattern and combining the spatial relative position relationship between the radar and the target, the radar echo signals r1(t), r2(t),…, r1(t) output by each sub-array are calculated. M (t), which is the radar echo signal that the simulation system needs to simulate.

2. The phased array radar RF injection simulation system constructed according to the phased array radar RF injection simulation method based on antenna performance equivalent inversion according to claim 1 is characterized by: Phased array radar RF injection simulation system, including: a host, an I / O interface adapter unit, a display control unit, the host interface end is connected to the data end of the radar under test through the I / O interface adapter unit, the host display end is connected to the display control unit through a cable, and the host output end is connected to the input end of the radar under test through a cable; the host includes: a baseband signal generating unit, a baseband signal modulating unit, an antenna beam forming unit, a baseband signal synthesizing unit, an up / down frequency conversion unit, a clock and local oscillator unit, the input end of the baseband signal generating unit is connected to the up / down frequency conversion unit through a cable, the baseband signal generating unit is connected to the up / down frequency conversion unit through a cable, The output end of the element is connected to the input end of the antenna beam forming unit through the baseband signal modulation unit, the output end of the antenna beam forming unit is connected to the up-conversion input end of the up / down conversion unit through the baseband signal synthesis unit, the up-conversion output end of the up / down conversion unit is connected to the input end of the radar under test through a cable, and the down-conversion input end of the up / down conversion unit is connected to the output excitation end of the radar under test through a cable; the oscillation end of the up / down conversion unit is connected to the clock and local oscillator unit, and the input end of the clock and local oscillator unit is connected to the output reference signal end of the radar under test through a cable; the output end of the clock and local oscillator unit is the clock signal output end.

3. The phased array radar RF injection simulation system constructed according to the phased array radar RF injection simulation method based on antenna performance equivalent inversion according to claim 2 is characterized by: The baseband signal generation unit is composed of a target echo simulation circuit, a clutter signal simulation circuit, an interference signal simulation circuit and an A / D module electrically connected. The input end of the A / D module is connected to the up / down conversion unit, and the output end of the A / D module is connected to one end of the target echo simulation circuit, the clutter signal simulation circuit and the interference signal simulation circuit. The other ends of the target echo simulation circuit, the clutter signal simulation circuit and the interference signal simulation circuit are respectively the output ends of the baseband signal generation unit.

4. The phased array radar RF injection simulation system constructed by the phased array radar RF injection simulation method based on antenna performance equivalent inversion according to claim 2 is characterized by: The baseband signal modulation unit is composed of an atmospheric absorption effect simulation circuit, a multipath effect simulation circuit, a weather attenuation simulation circuit, a Doppler frequency shift simulation circuit, and a distance delay simulation circuit which are electrically connected. The input / output ends of the baseband signal modulation unit are respectively provided with a target echo signal end, a clutter signal end, and an interference signal end.

5. The phased array radar RF injection simulation system constructed by the phased array radar RF injection simulation method based on antenna performance equivalent inversion according to claim 2 is characterized by: The antenna beamforming unit is composed of an antenna scanning analog circuit, a subarray pattern analog circuit, a subarray weighting analog circuit, and a subarray synthesis analog circuit. The input end of the antenna beamforming unit is provided with a target echo signal end, a clutter signal end, and an interference signal end. The output end of the antenna beamforming unit is provided with a target echo end, a clutter signal end, and an interference signal end of subarray 1, and a target echo end, a clutter signal end, and an interference signal end of subarray N.

6. The phased array radar RF injection simulation system constructed by the phased array radar RF injection simulation method based on antenna performance equivalent inversion according to claim 2 is characterized by: The baseband signal synthesis unit is composed of a subarray 1 signal synthesis and D / A module connected in series to a subarray N signal synthesis and D / A module connected in series. The subarray 1 signal end to the subarray N signal end are the multi-channel input ends of the baseband signal synthesis unit, and the subarray 1 D / A module end to the subarray N D / A module end are the multi-channel output ends of the baseband signal synthesis unit.

7. The phased array radar RF injection simulation system constructed by the phased array radar RF injection simulation method based on antenna performance equivalent inversion according to claim 2 is characterized by: The up / down conversion unit is composed of several up-conversion circuits and down-conversion circuits electrically connected. The up-conversion circuit is composed of an up-conversion module and an amplifier in series, and the down-conversion circuit is composed of a down-conversion module and an amplifier in series.

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