A high-isolation and high-precision direction-finding antenna array for a directional antenna and its implementation method

Abstract

The present invention belongs to the technical field of radio direction finding, and particularly relates to a high-isolation and high-precision directional antenna for direction finding and an implementation method thereof. A four-channel direction finder and a cavity are deployed to generate a calibration signal and output it to a band selection switch. The receiver records the amplitude and phase values of the four channels, calculates the error of each channel, and creates a sample mathematical model; calculates the original phase difference between two different positions; corrects the phase difference between two different positions; arranges all the calculated phase difference values into a matrix according to frequency and incident angle and archives it to obtain a theoretical sample; when direction finding on a target signal, calculates the correlation between the phase of the target signal received by the four-channel direction finder and the sample data, and performs peak search to traverse all possible directions θ , calculates each θ correlation under, and records the maximum value as the maximum incoming wave direction. The direction finding accuracy and real-time response ability of the direction finding device are improved, and the continuity and stability of the measurement data are ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of radio direction finding, and particularly relates to a high-isolation and high-precision directional antenna direction-finding antenna array and a method for realizing the same. Background Art

[0002] At present, domestic direction-finding antennas are mainly used in ground environments, such as fixed monitoring stations and monitoring vehicles. No matter which direction-finding system is adopted (such as the correlation interferometer direction-finding algorithm, the spatial spectrum direction-finding algorithm), its system architecture mostly realizes the reception and processing of target radio signals by switching antenna channels through a matrix switch and sharing radio frequency channels.

[0003] However, under the theoretical algorithm model, it is impossible to completely avoid the direction-finding error caused by the coupling between antennas. Therefore, using a directional antenna with high isolation can effectively reduce the shielding effect of structural components on signals and reduce the influence of this coupling on direction-finding accuracy. In scenarios with a relative moving speed of 20 m / s, especially exceeding 40 m / s, higher requirements are put forward for the real-time response ability of direction-finding equipment.

[0004] Existing equipment uses an algorithm to guide the matrix switch to switch channels to select the target antenna. A common nine-element three-channel direction-finding antenna array on the market requires 1 ms to detect a set of data. When the relative moving speed of the direction-finding target is 50 m / s and the phase error between antennas is 30°, this design will affect the direction-finding accuracy.

[0005] At present, most direction-finding equipment on the market is difficult to achieve high-precision and low-cost direction-finding for high-speed moving targets, and at the same time, it is impossible to ensure the continuity and stability of measurement data.

[0006] Therefore, how to improve the existing direction-finding antenna, avoid the direction-finding error caused by the coupling between antennas, reduce the shielding effect of structural components on signals, reduce the influence of this coupling on direction-finding accuracy, improve the real-time response ability of direction-finding equipment, and ensure the continuity and stability of measurement data are the technical problems that need to be solved urgently at present. Summary of the Invention

[0007] The purpose of the present invention is to provide a high-isolation and high-precision directional antenna direction-finding antenna array and a method for realizing the same, so as to improve the existing direction-finding antenna, avoid the direction-finding error caused by the coupling between antennas, reduce the shielding effect of structural components on signals, reduce the influence of this coupling on direction-finding accuracy, improve the real-time response ability of direction-finding equipment, and ensure the continuity and stability of measurement data.

[0008] To solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0009] In a first aspect, a method for realizing a high-isolation and high-precision directional antenna direction-finding antenna array is provided, including the following steps:

[0010] S1: Deploy a four-channel direction finder and a cavity composed of a 2GHz - 18GHz direction-finding antenna array, a 1GHz - 2GHz direction-finding antenna array, a 300MHz - 1GHz direction-finding antenna array, and a 30MHz - 300MHz direction-finding antenna array;

[0011] S2: The four-channel direction finder generates a calibration signal f 0 Output it to the frequency band selection switch. The receiver records the amplitude and phase values of the four channels, and calculates the phase error Δ ϕ 0, Δ ϕ 1, Δ ϕ 2, Δ ϕ 3. Taking the antenna 0 channel as the reference, then Δ ϕ 0 = 0;

[0012] S3: Create a sample mathematical model based on the phase of electromagnetic waves, spatial position, frequency, and incident angle:

[0013] ϕ = 2πxsinθ / λ + ϕ i ;

[0014] Wherein, ϕ is the phase; λ is the wavelength of the current signal; θ is the incident angle; x is the distance difference between two antennas; ϕ i is the antenna i at its coordinate position x i at the phase delay. When the serial number i is 0, ϕ0 is the initial reference phase of the array element, i ∈ 0, 1, 2, 3;

[0015] S4: Measure the original phase difference between two different positions x i and x j under the conditions of frequency f and the incoming wave direction θ expressed as Δϕ ij ( f, θ ), and the phase error between any two antennas Δϕ ij ( f, θ ), and the specific calculation formula is as follows:

[0016] Δϕ ij ( f, θ ) = 2πf (x j −x i ) sinθ / c ;

[0017] where f is the frequency, c is the speed of light 3*10^8 (m / s), x i is the antenna element i the distance from the coordinate origin, x j is the antenna element number j the distance from the coordinate origin, i, j ∈ 0, 1, 2, 3;

[0018] S5: Calculate the Δ f at the frequency θ and angle ϕ 01 , Δ ϕ 02 , Δ ϕ 03 , Δ ϕ 12 , Δ ϕ 13 , Δ ϕ 23 ;

[0019] where Δ ϕ 01 is the phase difference between antenna 0 and antenna 1, Δ ϕ 02 is the phase difference between antenna 0 and antenna 2, Δ ϕ 03 is the phase difference between antenna 0 and antenna 3, Δ ϕ 12 is the phase difference between antenna 1 and antenna 2, Δ ϕ 13 is the phase difference between antenna 1 and antenna 3, Δ ϕ 23 is the phase difference between antenna 2 and antenna 3;

[0020] S6: Arrange all the calculated phase difference values in S5 in a matrix according to the frequency and the incident angle and archive to obtain the theoretical samples;

[0021] S7: When direction finding the target signal, subtract the phase error in S2 from the target signal received by the four-channel direction finder and then calculate the difference between any two-phase values to obtain the test value of the phase difference relationship between each channel at this frequency point. Calculate the correlation between this phase difference test value and the sample data in step S6 and perform peak search to traverse all possible directions θ ,θ ∈(0, 90°), calculate each θ of the correlations, and record the maximum θ as θ max , θ max which is the maximum incoming wave direction.

[0022] Preferably, in the 2GHz - 18GHz direction - finding antenna array in step S1, four sine antennas are used and arranged in a one - dimensional linear array according to a non - uniform distribution;

[0023] The 1GHz - 2GHz direction - finding antenna array uses four sine antennas and is arranged in a one - dimensional linear array with non - uniform intervals;

[0024] The 300MHz - 1GHz direction - finding antenna array uses four reflector dipole antennas and is arranged in a one - dimensional linear array with uniform intervals;

[0025] The 30MHz - 300MHz direction - finding antenna array uses four directional loop antennas and is arranged in a one - dimensional linear array with uniform intervals.

[0026] In a second aspect, a high - isolation and high - precision directional antenna direction - finding antenna array is provided for implementing the implementation method of the high - isolation and high - precision directional antenna direction - finding antenna array. It includes a four - channel direction - finder and a cavity composed of a 2GHz - 18GHz direction - finding antenna array, a 1GHz - 2GHz direction - finding antenna array, a 300MHz - 1GHz direction - finding antenna array, and a 30MHz - 300MHz direction - finding antenna array. The total size of the direction - finding antenna array in each frequency band is less than or equal to 1.2 meters, and a directional antenna with a fixed phase center is used as the basic array element for direction - finding within its respective frequency band.

[0027] Preferably, the 1GHz - 2GHz direction - finding antenna array and the 2GHz - 18GHz direction - finding antenna array use directional antennas based on a sine shape, the 300MHz - 1GHz direction - finding antenna array uses dipole antennas with reflectors, and the 30MHz - 300MHz direction - finding antenna array uses directional loop antennas.

[0028] Preferably, the 2GHz - 18GHz direction - finding antenna array, the 1GHz - 2GHz direction - finding antenna array, the 300MHz - 1GHz direction - finding antenna array, and the 30MHz - 300MHz direction - finding antenna array all include antenna elements and mounting plates. The mounting plates are used to accurately position the antennas and provide electromagnetic shielding for subsequent modules.

[0029] Preferably, the four-channel direction finder further includes an amplifier, a frequency band selection switch, and a signal processing module. The amplifier is used to perform selectivity and gain adjustment on signals within a target frequency band, and the frequency band selection switch is used to match the received signals with corresponding antennas.

[0030] Preferably, the specific process of signal processing by the signal processing module is as follows:

[0031] Perform down-conversion processing on the received radio frequency signal to convert it into an intermediate frequency signal;

[0032] Perform analog-to-digital conversion on the intermediate frequency signal to generate a digital signal;

[0033] Output a calibration signal with the same frequency as the target signal and calculate to compensate for system errors.

[0034] The beneficial effects of the present invention include:

[0035] The high-isolation high-precision directional antenna direction finding antenna array and its implementation method provided by the present invention deploy a four-channel direction finder and a cavity, generate a calibration signal and output it to the frequency band selection switch. The receiver records the amplitude and phase values of the four channels, calculates the error of each channel, and creates a sample mathematical model; calculates the original phase difference between two different positions; corrects the phase difference between two different positions; arranges all the calculated phase difference values into a matrix according to frequency and incident angle and archives to obtain a theoretical sample; when direction finding a target signal, calculate the correlation between the phase of the target signal received by the four-channel direction finder and the sample data, and perform peak search to traverse all possible directions θ, calculate the correlation at each θ, and record the maximum value as the maximum incoming wave direction. It improves the direction finding accuracy and real-time response ability of the direction finding device, and ensures the continuity and stability of measurement data.

[0036] First of all, by adopting a non-uniform linear array layout, compared with the traditional circular array design, the space utilization efficiency and installation flexibility are significantly improved. The linear array layout can not only be efficiently deployed in a narrow space, but also has good concealment and adaptability, meeting the application requirements in complex environments. Combined with high-gain antenna technology, the system has achieved a qualitative leap in signal capture distance and coverage range, further meeting the actual needs of long-distance direction finding.

[0037] Secondly, the antenna design of the present invention is adopted, which not only ensures high gain but also ensures the stability of the phase center. Compared with the traditional antenna design, the stable phase center not only improves the direction finding accuracy of the system but also significantly reduces the error accumulation, especially prominent in complex electromagnetic environments. Compared with traditional antennas, this antenna has lower sidelobes in the radiation pattern and higher directional gain, enabling more accurate target positioning in complex electromagnetic environments. In addition, combined with advanced signal processing algorithms, the system performs excellently in the scenario of simultaneous direction finding of multiple targets, further improving the anti-interference ability and measurement accuracy.

[0038] Thirdly, an efficient multi-channel data acquisition and fast direction finding algorithm are adopted. By optimizing the antenna switching mechanism and signal processing flow, the system can complete target positioning and tracking at the millisecond level, significantly improving the response speed and direction finding accuracy, and meeting the application requirements in different scenarios.

[0039] Thirdly, an optimized four-channel four-element antenna array design is adopted. Compared with the traditional seven-element three-channel and nine-element three-channel direction finding arrays, it significantly reduces the hardware complexity and cost investment. By adopting the advanced correlation interferometer direction finding algorithm, the system has achieved a substantial improvement in data acquisition efficiency and direction finding accuracy. At the same time, the four-channel design can effectively suppress interference signals, further improving the anti-interference ability and robustness of the system.

[0040] Finally, it supports multi-channel continuous IQ (in-phase and quadrature) signal output, providing a rich data source for subsequent signal processing and analysis. Through the optimized signal acquisition mechanism, the system can achieve seamless data transmission and processing, significantly improving the stability and reliability of the system. At the same time, the integrated design of monitoring and direction finding functions is realized, which not only simplifies the operation process but also improves the integration and scalability of the system. Description of the Drawings

[0041] Figure 1 It is a schematic structural diagram of the 2GHz - 18GHz direction finding antenna array of the present invention.

[0042] Figure 2 It is a schematic structural diagram of the 1GHz - 2GHz direction finding antenna array of the present invention.

[0043] Figure 3 It is a schematic structural diagram of the 300MHz - 1GHz direction finding antenna array of the present invention.

[0044] Figure 4 It is a schematic structural diagram of the 20MHz - 300MHz direction finding antenna array of the present invention.

[0045] Figure 5 It is a schematic structural diagram of the high isolation and high precision directional antenna direction finding antenna array of the present invention.

[0046] Figure 6 This is a simulation diagram of the isolation of a periodic logarithmic antenna at the same distance for the sine antenna unit of the present invention.

[0047] Figure 7 This is a simulation curve of the isolation of a periodic logarithmic antenna at the same distance for the sine antenna unit of the present invention.

[0048] Figure 8 This is a simulation diagram of the isolation of a sine antenna at a certain distance for the sine antenna unit of the present invention.

[0049] Figure 9 This is the simulation data of the isolation of a periodic logarithmic antenna at the same distance for the sine antenna unit of the present invention.

[0050] Figure 10 This is a beam simulation diagram of the sine antenna unit of the present invention.

[0051] Figure 11 This is the 3D simulation result of the beam of the sine antenna unit of the present invention.

[0052] Reference numerals: 1 is a 2 GHz - 18 GHz sine antenna, 2 is a 1 GHz - 2 GHz sine antenna, 3 is a 300 MHz - 1 GHz dipole antenna, and 4 is a 20 MHz - 300 MHz loop antenna. Detailed implementation manners

[0053] The following further describes the present invention in detail with reference to the Figures 1 - 11 accompanying drawings:

[0054] Embodiment 1

[0055] Referring to the Figure 1 accompanying drawings, a method for implementing a high - isolation and high - precision direction - finding antenna array of a directional antenna includes the following steps:

[0056] S1: Deploy a four - channel direction - finder and a cavity composed of a 2 GHz - 18 GHz direction - finding antenna array, a 1 GHz - 2 GHz direction - finding antenna array, a 300 MHz - 1 GHz direction - finding antenna array, and a 30 MHz - 300 MHz direction - finding antenna array;

[0057] S2: The four - channel direction - finder generates a calibration signal f 0 and outputs it to a frequency - band selection switch. The receiver records the amplitude and phase values of the four channels, and calculates the phase errors Δ ϕ 0, Δ ϕ 1, Δ ϕ 2, Δ ϕ 3 of each channel at this frequency point with respect to the reference channel. Taking the 0 - th channel of the antenna as the reference, then Δ ϕ 0 = 0;

[0058] S3: Create a sample mathematical model based on the phase of electromagnetic waves, spatial position, frequency, and incident angle:

[0059] ϕ = 2πxsinθ / λ + ϕ i ;

[0060] Where ϕ is the phase; λ is the wavelength of the current signal; θ is the incident angle; x is the distance difference between two antennas; ϕ i is the antenna i at its coordinate position x i The phase delay at the location, when the sequence number i is 0, ϕ0 is the initial reference phase of the array element, i ∈ 0, 1, 2, 3;

[0061] S4: Measure the original phase difference between two different positions x i and x j at frequency f and incident wave direction θ The original phase difference is expressed as Δϕ ij ( f, θ ), and the phase error between any two antennas Δϕ ij ( f, θ ), and the specific calculation formula is as follows:

[0062] Δϕ ij ( f, θ ) = 2πf ( x j −x i ) sinθ / c ;

[0063] Where f is the frequency, c is the speed of light 3 * 10^8 (m / s), x i is the distance between the antenna array element i and the origin of coordinates, x j is the antenna array element number j and the distance from the origin of coordinates, i, j ∈ 0, 1, 2, 3;

[0064] S5: Calculate the frequency f , angle θΔ under ϕ 01 、Δ ϕ 02 、Δ ϕ 03 、Δ ϕ 12 、Δ ϕ 13 、Δ ϕ 23 ;

[0065] where Δ ϕ 01 is the phase difference between antenna 0 and antenna 1, Δ ϕ 02 is the phase difference between antenna 0 and antenna 2, Δ ϕ 03 is the phase difference between antenna 0 and antenna 3, Δ ϕ 12 is the phase difference between antenna 1 and antenna 2, Δ ϕ 13 is the phase difference between antenna 1 and antenna 3, Δ ϕ 23 is the phase difference between antenna 2 and antenna 3;

[0066] S6: Arrange all the calculated phase difference values in S5 in a matrix according to frequency and angle of incidence and archive to obtain a theoretical sample;

[0067] S7: When direction finding the target signal, subtract the phase error in S2 from the target signal received by the four-channel direction finder and then calculate the difference between any two-phase values to obtain the test value of the phase difference relationship between each channel at this frequency point. Calculate the correlation between this phase difference test value and the sample data in step S6, and perform peak search to traverse all possible directions θ , θ ∈(0, 90°), calculate the correlation for each θ and record the maximum θ as θ max , θ max is the maximum incoming wave direction.

[0068] In this embodiment, in the 2 GHz - 18 GHz direction finding antenna array in step S1, four sine antennas are used and arranged in a one-dimensional linear array according to non-uniform distribution;

[0069] The 1 GHz - 2 GHz direction finding antenna array uses four sine antennas and is arranged in a one-dimensional linear array with non-uniform intervals;

[0070] The 300 MHz - 1 GHz direction - finding antenna array uses four reflector dipole antennas, arranged in a one - dimensional linear array at uniform intervals;

[0071] The 30 MHz - 300 MHz direction - finding antenna array uses four directional loop antennas, arranged in a one - dimensional linear array at uniform intervals.

[0072] Embodiment 2

[0073] Based on Embodiment 1, a high - isolation and high - precision directional antenna direction - finding antenna array for implementing the method of realizing the high - isolation and high - precision directional antenna direction - finding antenna array includes a four - channel direction - finder and a cavity composed of a 2 GHz - 18 GHz direction - finding antenna array, a 1 GHz - 2 GHz direction - finding antenna array, a 300 MHz - 1 GHz direction - finding antenna array, and a 30 MHz - 300 MHz direction - finding antenna array. The total size of the direction - finding antenna array in each frequency band is less than or equal to 1.2 meters, and a directional antenna with a fixed phase center is used as the basic array element for direction - finding within its respective frequency band. The 2 GHz - 18 GHz direction - finding antenna array, 1 GHz - 2 GHz direction - finding antenna array, 300 MHz - 1 GHz direction - finding antenna array, and 30 MHz - 300 MHz direction - finding antenna array all include antenna elements and mounting plates. The mounting plates are used to accurately position the antennas and provide electromagnetic shielding for subsequent modules.

[0074] Embodiment 3

[0075] Based on Embodiment 1 or Embodiment 2, as shown in Figure 1 the 1 GHz - 2 GHz direction - finding antenna array and the 2 GHz - 18 GHz direction - finding antenna array use sinusoidal - shaped directional antennas, the 300 MHz - 1 GHz direction - finding antenna array uses dipole antennas with reflectors, and the 30 MHz - 300 MHz direction - finding antenna array uses directional loop antennas.

[0076] The 2 GHz - 18 GHz direction - finding antenna array uses a sinusoidal Sinous antenna as the basic unit. As shown in Figures 1 - 4 four 2 GHz - 18 GHz sinusoidal antennas are arranged in a straight line on the same plane according to a certain distance relationship to ensure the consistency of the phase center. This frequency band covers a 90 - degree direction - finding range. According to the requirement of the shortest baseline relationship between the direction - finding angle range, it is calculated that the shortest baseline requirement for this frequency band is ≤ 11.77 mm, which is much smaller than the antenna size. Therefore, the distance relationship between the antennas is arranged according to the wiring principles of staggered double - baseline and virtual double - baseline, and the size can be limited within 1.3 m. The coordinates of the four antennas in this frequency - band linear array are:

[0077] A0: 0; A1: 82.5 mm; A2: 153.3 mm; A3: 1152 mm.

[0078] As shown Figure 2 in Figure 2 , the 1GHz - 2GHz direction - finding antenna array still uses the sine Sinous antenna as the basic unit. As shown Figures 1 - 4 in Figures 1 - 4 , four 1GHz - 2GHz sine antennas are arranged in a straight line on the same plane according to a certain distance relationship to ensure the consistency of the phase center. According to the size requirement of the shortest baseline in this frequency band, it is calculated that the shortest distance is much smaller than the antenna size in this frequency band. Therefore, the distance relationship between the antennas is arranged according to the wiring principles of the staggered double - baseline and the virtual double - baseline, and the size can be limited within 1.1m. The coordinates of the four antennas in this frequency - band linear array are:

[0079] A0: 0; A1: 418mm; A2: 840mm; A3: 1050mm.

[0080] As shown Figure 3 in Figure 3 , the 300MHz - 1GHz direction - finding antenna array adopts a short - circuited loaded dipole reflector structure. Four antennas in this frequency band are arranged in a straight line on the same plane according to a certain distance relationship to ensure the consistency of the phase center. The relative coordinates of the four antennas are:

[0081] A0: 0; A1: 210mm; A2: 420mm; A3: 630mm.

[0082] As shown Figure 4 in Figure 4 , the 20MHz - 300MHz direction - finding antenna array adopts a cylindrical antenna element layout. Four antennas in this frequency band are arranged in a straight line on the same plane according to a certain distance relationship to ensure the consistency of the phase center. The relative coordinates of the four antennas are:

[0083] A0: 0; A1: 350mm; A2: 700mm; A3: 1050mm.

[0084] By adding a four - channel receiver at the rear end of the antenna array, radio direction - finding in the 90° direction (this angle determines the distance relationship between the antennas) can be achieved, and its direction - finding accuracy can reach 1° RMS. RMS is 1 times sigma or 1 times the standard deviation. The layouts of each frequency band are as shown Figures 1 - 4 in Figures 1 - 4 . As shown Figure 5 in Figure 5 , when the subsequent four - channel direction - finder is connected to the antenna array shown, there is no need to switch the antenna channels when monitoring and direction - finding the target signal. As shown Figures 6 - 11 in the simulation data of the sine antenna unit shown Figure 6 in Figure 6 , X is the X - axis Figure 8 in Figure 8 , X, Y, and Z respectively represent the X - axis, Y - axis, and Z - axis in the coordinate system, and U, V, and N respectively represent the U - axis, V - axis, and N - axis in another coordinate system.

[0085] The four-channel direction finder further includes an amplifier, a frequency band selection switch, and a signal processing module. The amplifier is used to perform selective and gain adjustment on signals within the target frequency band, and the frequency band selection switch is used to match the received signals with the corresponding antennas.

[0086] The specific process of signal processing by the signal processing module is as follows: perform down-conversion processing on the received radio frequency signal to convert it into an intermediate frequency signal; perform analog-to-digital conversion on the intermediate frequency signal to generate a digital signal; output a calibration signal with the same frequency as the target signal, and calculate and compensate for the system error.

[0087] In summary, the high-isolation high-precision directional antenna and its implementation method provided by the present invention deploy a four-channel direction finder and a cavity, generate a calibration signal and output it to the frequency band selection switch. The receiver records the amplitude and phase values of the four channels, calculates the error of each channel, and creates a sample mathematical model; calculates the original phase difference between two different positions; corrects the phase difference between two different positions; arranges all the calculated phase difference values into a matrix according to frequency and incident angle and archives it to obtain a theoretical sample; when direction-finding a target signal, calculate the correlation between the phase of the target signal received by the four-channel direction finder and the sample data, and perform peak search to traverse all possible directions θ, calculate the correlation at each θ, and record the maximum value as the maximum incoming wave direction. This improves the direction-finding accuracy and real-time response ability of the direction-finding device, and ensures the continuity and stability of measurement data.

[0088] By adopting a non-uniform linear array layout, compared with the traditional circular array design, the space utilization efficiency and installation flexibility are significantly improved. It can not only be efficiently deployed in a narrow space, but also has good concealment and adaptability, and is suitable for application requirements in complex environments. With the antenna design of the present invention, not only high gain is ensured, but also the stability of the phase center is ensured. Compared with the traditional antenna design, the stable phase center not only improves the direction-finding accuracy of the system, but also significantly reduces error accumulation. Compared with the traditional antenna, this antenna has lower sidelobes in the radiation pattern and higher directional gain, and can achieve more accurate target positioning in a complex electromagnetic environment. Combined with advanced signal processing algorithms, the anti-interference ability and measurement accuracy are further improved.

[0089] By adopting an efficient multi-channel data acquisition and fast direction finding algorithm, and optimizing the antenna switching mechanism and signal processing flow, the system can complete target positioning and tracking at the millisecond level, significantly improving the response speed and direction finding accuracy, and meeting the application requirements in different scenarios. By adopting an advanced correlation interferometer direction finding algorithm, the system has achieved a substantial improvement in data acquisition efficiency and direction finding accuracy. At the same time, the four-channel design can effectively suppress interference signals, further improving the anti-interference ability and robustness of the system. It supports multi-channel continuous IQ signal output, providing a rich data source for subsequent signal processing and analysis. Through the optimized signal acquisition mechanism, the system can achieve seamless data transmission and processing, significantly enhancing the stability and reliability of the system. At the same time, an integrated design of monitoring and direction finding functions is realized, which not only simplifies the operation process, but also improves the integration and scalability of the system.

Claims

1. A method for realizing a high-isolation and high-precision directional antenna direction finding antenna array, characterized in that: The following steps are involved: S1: Deploy a four-channel direction finder and cavity consisting of a 2GHz-18GHz direction finding antenna array, a 1GHz-2GHz direction finding antenna array, a 300MHz-1GHz direction finding antenna array, and a 30MHz-300MHz direction finding antenna array; S2: The four-channel direction finder generates a correction signal f 0 Output to the frequency band selection switch, the receiver records the amplitude and phase values ​​of the four channels, and calculates the phase error Δ between the frequency point of the correction signal of each channel and the reference channel ϕ 0, Δ ϕ 1. Δ ϕ 2. Δ ϕ 3. Taking antenna channel 0 as the reference, Δ ϕ 0=0; S3: Create a sample mathematical model based on the phase of an electromagnetic wave versus its spatial position, frequency, and angle of incidence: ϕ = 2πxsinθ / λ+ϕ i ； in, ϕ It is the phase; λ is the wavelength of the current signal; θ is the angle of incidence; x is the distance difference between the two antennas; ϕ i It's an antenna i At its coordinate position x i The phase delay at i When it is 0, ϕ0 is the initial reference phase of the array element, i∈0, 1, 2, 3; S4: Measuring two different locations x i and x j The frequency between f and the direction of incoming waves θ The original phase difference under the condition is expressed as Δϕ ij ( f,θ ), the phase error between any two antennas Δϕ ij ( f,θ ), the specific calculation formula is as follows: Δϕ ij ( f,θ ) = 2πf ( x j −x i ) sinθ / c ； in, f is the frequency, c The speed of light is 3*10^8 (m / s), x i Antenna array element i The distance from the origin of the coordinate system, x j Number the antenna elements j The distance from the origin of the coordinate system, i, j ∈0,1,2,3; S5: Calculate the frequency in sequence f ,angle θ Δ ϕ 01 , Δ ϕ 02 , Δ ϕ 03 , Δ ϕ 12 , Δ ϕ 13 , Δ ϕ 23 ; Among them, Δ ϕ 01 is the phase difference between antenna 0 and antenna 1, Δ ϕ 02 is the phase difference between antenna 0 and antenna 2, Δ ϕ 03 is the phase difference between antenna 0 and antenna 3, Δ ϕ 12 is the phase difference between antenna 1 and antenna 2, Δ ϕ 13 is the phase difference between antenna 1 and antenna 3, Δ ϕ 23 is the phase difference between antenna 2 and antenna 3; S6: Arrange all the phase difference values ​​calculated in S5 into a matrix according to frequency and incident angle and archive it to obtain a theoretical sample; S7: When finding the direction of the target signal, the phase difference relationship test value between the channels at its frequency point can be obtained by subtracting the phase error in S2 from the target signal received by the four-channel direction finder and then taking the difference between any two phase values. The phase difference test value is correlated with the sample data in step S6, and a peak search is performed to traverse all possible directions. θ , θ ∈(0,90°), calculate each θ The correlation under θ for θ max , θ max This is the direction of the maximum incoming wave.

2. The method for realizing a high-isolation and high-precision directional antenna direction finding antenna array according to claim 1, characterized in that: The 2 GHz-18 GHz direction finding antenna array in step S1 uses four sinusoidal antennas arranged in a non-uniform distribution into a one-dimensional linear array; The 1GHz-2GHz direction-finding antenna array uses four sinusoidal antennas arranged at non-uniform intervals to form a one-dimensional linear array; The 300MHz-1GHz direction-finding antenna array uses four reflective surface dipole antennas, which are evenly spaced and arranged into a one-dimensional linear array; The 30MHz-300MHz direction-finding antenna array uses four directional loop antennas that are evenly spaced and arranged to form a one-dimensional linear array.

3. A high-isolation and high-precision directional antenna direction-finding antenna array, used to implement a method for implementing a high-isolation and high-precision directional antenna direction-finding antenna array as claimed in any one of claims 1 to 2, characterized in that: It includes a four-channel direction finding machine and cavity consisting of a 2GHz-18GHz direction finding antenna array, a 1GHz-2GHz direction finding antenna array, a 300MHz-1GHz direction finding antenna array, and a 30MHz-300MHz direction finding antenna array. The total size of the direction finding antenna array in each frequency band is less than or equal to 1.2 meters, and a directional antenna with a fixed phase center is used as the basic array element for direction finding in each frequency band.

4. The high-isolation and high-precision directional antenna direction finding antenna array according to claim 3, characterized in that: The 1GHz-2GHz direction-finding antenna array and the 2GHz-18GHz direction-finding antenna array use directional antennas based on a sinusoidal shape, the 300MHz-1GHz direction-finding antenna array uses a dipole antenna with a reflecting surface, and the 30MHz-300MHz direction-finding antenna array uses a directional loop antenna.

5. The high-isolation and high-precision directional antenna direction finding antenna array according to claim 4, characterized in that: The 2GHz-18GHz direction-finding antenna array, the 1GHz-2GHz direction-finding antenna array, the 300MHz-1GHz direction-finding antenna array and the 30MHz-300MHz direction-finding antenna array all include an antenna unit and a mounting plate, and the mounting plate is used to accurately locate the antenna position and to perform electromagnetic shielding on subsequent modules.

6. The high-isolation and high-precision directional antenna direction finding antenna array according to claim 3, characterized in that: The four-channel direction finder also includes an amplifier, a frequency band selection switch and a signal processing module. The amplifier is used to select and adjust the gain of the signal in the target frequency band, and the frequency band selection switch is used to match the received signal with the corresponding antenna.

7. The high-isolation and high-precision directional antenna direction finding antenna array according to claim 6, characterized in that: The specific process of the signal processing module performing signal processing is as follows: Down-convert the received radio frequency signal into an intermediate frequency signal; Perform analog-to-digital conversion on the intermediate frequency signal to generate a digital signal; Output a correction signal with the same frequency as the target signal to calculate and compensate for system errors.

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