An ultra-wideband high aperture efficiency planar reflectarray antenna

Abstract

The present invention relates to an ultra-wideband high-aperture efficiency planar reflectarray antenna, which includes a reflectarray and a feed antenna suspended directly above the reflectarray; the reflectarray is composed of a plurality of ultra-wideband units distributed in an array; the ultra-wideband unit includes a first dielectric substrate, a metal floor and a vertical dielectric substrate; a butterfly-shaped wide-arm dipole is printed on the front of the first dielectric substrate, and a first rectangular hole penetrating the first dielectric substrate is arranged at the center of the wide-arm dipole; a phase delay line in the form of a rectangular patch is printed on both sides of the vertical dielectric substrate; a second rectangular hole penetrating the metal floor is arranged in the middle of the metal floor; the vertical dielectric substrate passes through the second rectangular hole and the first rectangular hole and is electrically connected to the wide-arm dipole. The present invention has the advantages of ultra-wideband, high gain, high aperture efficiency and easy integration, and can be applied to long-distance communication systems that require high-gain antennas, such as deep space exploration, satellite communication, radar monitoring, etc.

Description

Technical Field

[0001] The present invention relates to the field of antenna and electromagnetic wave technology, and in particular to an ultra-wideband high-aperture efficiency planar reflective array antenna. Background Art

[0002] With the increase of wireless transmission rate and the increasing complexity of communication system functions, high gain and ultra-wideband are two important research directions in the field of antennas; parabolic antennas and phased array antennas have higher gain, but parabolic antennas are large in size and less flexible, and phased array antennas have complex feeding networks and larger transmission losses. Planar reflectarray antennas combine the advantages of both. They are composed of two-dimensional arrays of metal patch units, fed by directional antennas, and compensate for the phase delay difference between the feed source and different units by adjusting the parameters of the units. Therefore, they have the advantages of low profile, low cost, light weight, easy integration, and simple feeding network, and can better meet the communication and detection needs of the platform. However, the bandwidth of the planar reflectarray is limited by the following two reasons: 1. The bandwidth of the unit itself is narrow, and the consistency of the reflection phase is poor within the broadband range; 2. The spatial phase delay difference from the feed source to different array units changes with frequency, and it is difficult to accurately compensate for the phase delay of each frequency point within the broadband range by adjusting the size, etc., so a large phase error will be generated, which will reduce the antenna gain within the broadband. Therefore, the bandwidth of most planar reflectarray antennas is narrow at present, which cannot meet the broadband requirements of increasingly complex communication systems. However, in the few studies on ultra-wideband planar reflectarray antennas currently available, the above two factors that limit bandwidth cannot be completely resolved, resulting in large phase errors within the ultra-wideband and low antenna aperture efficiency. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide an ultra-wideband high-aperture efficiency planar reflectarray antenna, which solves the problem that the prior art cannot break through the limitation of narrow unit reflection bandwidth and the difficulty in accurately compensating phase delay within a wideband range.

[0004] The objective of the present invention is achieved through the following technical scheme: an ultra-wideband high-aperture efficiency planar reflectarray antenna, comprising a reflectarray and a feed antenna suspended directly above the reflectarray; the reflectarray is composed of a plurality of ultra-wideband units distributed in an array; the ultra-wideband unit comprises a first dielectric substrate, a metal floor and a vertical dielectric substrate; a butterfly-shaped wide-arm dipole is printed on the front of the first dielectric substrate, and a first rectangular hole penetrating the first dielectric substrate is arranged at the center of the wide-arm dipole; phase delay lines in the form of rectangular patches are printed on both sides of the vertical dielectric substrate; a second rectangular hole penetrating the metal floor is arranged in the middle of the metal floor; the vertical dielectric substrate passes through the second rectangular hole and the first rectangular hole and is electrically connected to the wide-arm dipole.

[0005] The feed antenna comprises a second dielectric substrate, and logarithmic periodic structure antennas are printed on both the front and back surfaces of the second dielectric substrate, and the logarithmic periodic structure antennas printed on the front and back surfaces are symmetrical to each other.

[0006] The size of the first rectangular hole is the same as that of the vertical dielectric substrate and is smaller than that of the second rectangular hole. The vertical dielectric substrate passes through the second rectangular hole without contacting the metal floor, and penetrates into the first rectangular hole so that the phase delay line is electrically connected to the wide-arm dipole. The reflection phase of the ultra-wideband unit is adjusted by adjusting the phase delay line.

[0007] A method for adjusting the reflection phase consistency in a wideband of an ultra-wideband high-aperture efficiency planar reflectarray antenna, the method comprising:

[0008] Optimization algorithm step: passing the given initial values ​​of the ultra-wideband unit structural characteristic parameters that need to be optimized to the simulation modeling step;

[0009] Simulation modeling steps: adding variables, automatic modeling, setting boundary conditions and material parameters, setting ports, configuring solution frequency and scanning parameters by calling library functions, scanning the length of the phase delay line to obtain the change curve of the reflection phase at different frequency points with the phase delay line length L and export it to the data processing step;

[0010] Data processing step: find the equivalent reflection length and phase delay line length curves of each frequency point, then find the mean of all curves, and then find the sum of the variances of each curve and the mean curve and pass it back to the optimization algorithm step.

[0011] The data processing steps specifically include:

[0012] According to the calculation formula of equivalent reflection length, the curve of equivalent reflection length changing with L at each frequency point is obtained;

[0013] Then the mean of all the curves is calculated, and the equivalent phase length and phase delay line length of each frequency point are compared with the mean curve, and the sum of the variances vL of all the curves is calculated, and vL is used as an indicator to judge the phase consistency of broadband internal reflection;

[0014] The value of vL is passed back to the optimization algorithm step as a basis for judging whether the PSO converges.

[0015] The optimization algorithm steps specifically include:

[0016] Inputting the initial values ​​of the structural characteristic parameters of the ultra-wideband unit into the simulation modeling step;

[0017] Determine whether the sum of variances vL returned by the data processing step meets the convergence condition. If the sum of variances vL is less than the set convergence value, the optimization is terminated and the optimized feature parameters are output;

[0018] If the sum of the variances vL is greater than the set convergence value, a new set of characteristic parameters is generated according to the iteration method of the particles and the simulation modeling step and the data processing step are repeated until the sum of the variances vL returned is less than the set convergence value.

[0019] A method for calculating array phase distribution of an ultra-wideband high-aperture efficiency planar reflectarray antenna, the method comprising:

[0020] Calculate the reflection phase that needs to be compensated for each ultra-wideband unit distributed in the array;

[0021] The equivalent reflection length distribution of each ultra-wideband unit is calculated according to the concept of equivalent reflection length;

[0022] The PSO algorithm is used to comprehensively optimize the equivalent reflection length of each frequency point to obtain the phase distribution of the optimal weight combination.

[0023] The calculation of the reflection phase that needs to be compensated for each ultra-wideband unit distributed in the array includes:

[0024] The phase center of the feed antenna is equivalent to an ideal point source, and the incident phase of the spherical wave radiated by the point source arriving at each ultra-wideband unit on the array plane, i.e., the array element, is calculated;

[0025] According to the target beam direction of the reflective array, the outgoing wavefront direction is determined and the outgoing phase required by each ultra-wideband unit is calculated;

[0026] Calculate the difference between the incident and outgoing phases of each element in the reflective array, and solve the input and output phase change value of each ultra-wideband unit position on the reflective surface;

[0027] According to the relative position between the feed source and the ultra-wideband unit in the Cartesian coordinate system, the phase value of the incident point of the array element on the reflective array is obtained. Where k = 2π / λ is the wave vector of electromagnetic wave propagation in free space, (i, j) represents the grid point position at the i-th row and j-th column, the array element period is p, and the feed source position is (x 0 ,y 0 ,z 0 );

[0028] According to the outgoing beam direction and combined with the two-dimensional phased array beam synthesis theory, each array element on the reflective array is equivalent to an isotropic point source with the same amplitude and fixed phase difference. Direction, calculate the array element outgoing phase

[0029] Then the difference between the reflected phase and the incident phase of each array element is calculated, that is, the compensated reflected phase is:

[0030]

[0031] The PSO algorithm is used to comprehensively optimize the equivalent reflection length of each frequency point to obtain the phase distribution of the optimal weight combination, including:

[0032] The weight of each frequency point ω i As the parameter to be optimized, according to the N solution frequency points within the ultra-wideband range, the particle dimension to be optimized is determined to be N;

[0033] Initialize particles and particle speeds, and calculate the average of the maximum phase error of the array elements at each frequency point and variance s 2 error Detect as a particle fitness function and update particle velocity and particle position;

[0034] The smallest and As the optimization target, the best solution in each iteration of the particle swarm is stored in the pbest parameter, and the best solution of all particles is stored in the gbest parameter. After reaching the maximum number of iterations, the optimal weight combination is output.

[0035] The present invention has the following advantages:

[0036] 1. Break through the limitation of narrow unit reflection bandwidth and improve the consistency of reflection phase within the ultra-wideband: use planar dipoles as array units, and adjust the reflection phase by adjusting the length of the vertically placed phase delay line; use simulation modeling-data processing-optimization computing environment, combined with PSO to perform parameter optimization calculations, and reduce the difference in reflection phase within the unit ultra-wideband.

[0037] 2. Break through the limitation that phase delay in the ultra-wideband range is difficult to accurately compensate. By calculating the equivalent phase delay length, the parameters of different units of the array are calculated, and the weights of the equivalent phase delay length distribution between different frequency points are optimized in combination with PSO, so as to reduce the phase error in the ultra-wideband and improve the aperture efficiency in the ultra-wideband.

[0038] 3. It has the advantages of ultra-wideband, high gain, high aperture efficiency and easy integration. It can be used in long-distance communication systems that require high-gain antennas, such as deep space exploration, satellite communications, radar monitoring, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a structural schematic diagram of the present invention;

[0040] Figure 2 is a schematic diagram of the structure of the reflect array;

[0041] Figure 3 The result diagram of the feed antenna is shown below;

[0042] Figure 4 Schematic diagram of the process of PSO parameter optimization;

[0043] Figure 5 It is a schematic diagram of the incident wave path from the feed antenna to the reflector array element;

[0044] Figure 6 Schematic diagram of reflect array output beam synthesis;

[0045] Figure 7 Schematic diagram of equivalent reflection length at each frequency point;

[0046] Figure 8 It is a flowchart of the equivalent reflection length synthesis method based on the PSO algorithm;

[0047] Fig. 9 This is a comparison diagram of the phase error at seven frequencies from 4 to 10 GHz using the single frequency phase distribution calculation method.

[0048] Fig.10 This is a comparison chart of the phase error at seven frequency points from 4 to 10 GHz using the equivalent reflection length calculation method based on the PSO algorithm;

[0049] Fig.11 It is a schematic diagram of the curve of S11 amplitude changing with L;

[0050] Fig.12 It is a schematic diagram of the curve of S11 phase changing with L;

[0051] Fig.13 This is a schematic diagram of the S-parameter simulation results of the feed antenna;

[0052] Fig.14 The directivity diagram of each frequency point when phi=0°;

[0053] Fig.15 The directivity diagram of each frequency point is phi = 90°;

[0054] Fig.16 is a schematic diagram of the curve of array gain changing with frequency;

[0055] Fig.17 is the curve of array aperture efficiency changing with frequency;

[0056] In the figure: 1-feed antenna, 2-reflection array, 3-first dielectric substrate, 4-wide arm dipole, 5-vertical dielectric substrate, 6-phase delay line, 7-metal floor, 8-first rectangular hole, 9-second rectangular hole, 10-logarithmic periodic structure antenna, 11-second dielectric substrate. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the present application provided below in conjunction with the drawings is not intended to limit the scope of protection of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application. The present invention is further described below in conjunction with the drawings.

[0058] The present invention first uses a sub-wavelength plane dipole as the basic form of the reflective array unit, and adjusts the reflection phase of the unit by a phase delay line 6 printed on a vertically placed dielectric substrate. In order to improve the consistency of the reflection phase in the ultra-wideband, a simulation modeling-data processing-optimization computing environment is proposed, and a particle swarm algorithm (PSO) is used to adjust the linearity of the reflection phase in the wideband. A logarithmic periodic antenna is used as the feed source of the reflective array, and the phase distribution of the ultra-wideband reflection array is calculated based on the equivalent reflection length, and the phase distribution of multiple frequency points in the ultra-wideband is comprehensively calculated by PSO, which includes the following contents:

[0059] like Figure 1 and Figure 2 As shown, it includes a reflective array 2 and a feed antenna 1 suspended just above the reflective array 2; the reflective array is composed of a plurality of ultra-wideband units distributed in an array; the ultra-wideband unit includes a first dielectric substrate 3, a metal floor 7 and a vertical dielectric substrate 5; a metal pattern of a butterfly-shaped wide-arm dipole 4 is printed on the front of the first dielectric substrate 3, and a first rectangular hole 8 penetrating the first dielectric substrate 3 is arranged at the center of the wide-arm dipole 4; a phase delay line 6 in the form of a rectangular patch is printed on both sides of the vertical dielectric substrate 5; a second rectangular hole 9 penetrating the metal floor 7 is arranged in the middle of the metal floor 7; the vertical dielectric substrate 5 passes through the second rectangular hole 9 and the first rectangular hole 8 and is electrically connected to the wide-arm dipole 4.

[0060] Furthermore, the size of the first rectangular hole 8 is the same as that of the vertical dielectric substrate 5 and smaller than that of the second rectangular hole 9. The vertical dielectric substrate 5 passes through the second rectangular hole 9 without contacting the metal floor 7, and penetrates into the first rectangular hole 8 so that the phase delay line 6 is electrically connected to the wide-arm dipole 4. The reflection phase of the ultra-wideband unit is adjusted by adjusting the phase delay line.

[0061] Because the length of the phase delay line 6 may be greater than the spacing between the first dielectric substrate 3 and the metal floor 7, it will pass through the middle of the metal floor 7. The size of the second rectangular hole 9 is set to be greater than the size of the vertical dielectric substrate 5, so that the phase delay line 6 will not contact the metal floor 7, and the part of the phase delay line 6 located below the metal floor 7 will not lose its function. In actual engineering applications, the area of ​​the first dielectric substrate 3 and the metal floor 7 can be increased, and a circle of circular holes can be made around them for installing nylon columns that fix the positions of the first dielectric substrate 3 and the metal floor 7.

[0062] The first dielectric substrate 3 and the vertical dielectric substrate 5 both use Rogers RO 4003C as dielectric substrates, with a dielectric constant of 3.55 and a dielectric loss of 0.0027.

[0063] The arm length of the wide-arm dipole 4 is about one-third of the wavelength at the center frequency, and it is directly connected to the phase delay line 6, and the end of the phase delay line 6 is equivalent to an open-circuit terminal. Ideally, after the plane wave is excited, an effective resonance is excited at the wide-arm dipole 4, and then transmitted to the open-circuit terminal through the phase delay line 6, and then returns along the phase delay line 6 after total reflection, and then reflects through the wide-arm dipole 4. Therefore, the phase shift is proportional to twice the length of the phase delay line, which can be expressed as: Where β is the propagation constant in the medium and Δl is the length of the phase delay line.

[0064] Furthermore, if Figure 3 As shown, wherein Figure (a) represents the front side and Figure (b) represents the back side, the feed antenna 1 includes a second dielectric substrate 11, and a logarithmic periodic structure antenna 10 is printed on both the front and back sides of the second dielectric substrate 11, and is symmetrical to each other; wherein the second dielectric substrate 11 also uses Rogers RO 4003C as the dielectric substrate material.

[0065] There are many parameters that affect the unit reflection phase, and each parameter changes independently. It is difficult to obtain the most ideal result by using the traditional parameter step-by-step scanning method. At the same time, to evaluate the unit reflection phase performance, it is necessary to pay attention to the change law between the characteristic parameters and the reflection phase at different frequencies, and the evaluation criteria are difficult to select. Based on this research difficulty, the present invention proposes a set of simulation modeling-data processing-optimization computing environment, which adjusts the consistency of the reflection phase in a wide band by adjusting the characteristic parameters of the unit in combination with the optimization algorithm.

[0066] like Figure 4As shown in the figure, the entire computing environment is divided into three parts: the first part is the optimization algorithm, which first gives the initial value of the characteristic parameter of the unit structure to be optimized, and passes this initial value to the simulation modeling part. In the simulation modeling part, by calling library functions, operations such as adding variables, automatic modeling, setting boundary conditions and material parameters, setting ports, configuring solution frequencies and scanning parameters are realized. After the modeling is completed, the CPU automatically starts the full-wave simulation calculation. After the calculation is completed, the S parameter curve is exported, and the third part of the data processing stage is entered.

[0067] In order to determine the consistency of the reflection phase in a wide frequency band, the equivalent reflection length of the unit is defined as:

[0068]

[0069] Since the equivalent reflection length eliminates the influence of frequency, the following steps are used to determine the consistency of the reflection phase in a wide band: 1. First, in the simulation calculation stage, the length of the phase delay line 6 is scanned to obtain the curve of the reflection phase at different frequency points with the length of the phase delay line 6 (L); 2. According to the calculation formula of the equivalent reflection length, the curve of the equivalent reflection length at each frequency point with L is obtained; 3. The mean of all curves is obtained, and then the equivalent phase length-phase delay line 6 length curve of each frequency point is compared with the mean curve to obtain the sum of the variances of all curves (vL), which is used as an indicator for judging the consistency of the reflection phase in a wide band. If vL is larger, it proves that the difference in the reflection phase is greater and the reflection bandwidth of the unit is narrower. Therefore, when optimizing, reducing the value of vL as much as possible can increase the reflection bandwidth of the unit.

[0070] The value of vL is passed back to the optimization algorithm as the convergence criterion of PSO. If the sum of the variances is less than the set convergence value, the optimization is terminated and the optimized characteristic parameters are output; if the sum of the variances is greater than the set convergence value, a new set of characteristic parameters is generated according to the iteration method of the particles, and the simulation modeling-data processing process is continued. In the next iteration, the speed parameter will be adjusted according to the position of the optimal particle in the population (the minimum sum of the variances), so as to change the position and quickly converge to the optimal point, and finally achieve global convergence.

[0071] At a fixed feed source distance, the difference in the path length of different frequency bands causes a large error in the reflection surface beam synthesis, which makes it difficult to accurately compensate for the phase delay in the broadband. Accordingly, the present invention proposes a phase calculation method based on non-frequency-variant equivalent reflection length and PSO weight optimization, which can effectively reduce the phase error in the ultra-wideband range, thereby improving the antenna gain and aperture efficiency in the ultra-wideband; it specifically includes the following contents:

[0072] (1) Calculate the reflection phase that needs to be compensated for each array element (ultra-wideband element): First, the phase center of the feed antenna is equivalent to an ideal point source, and the incident phase of the spherical wave radiated by the point source reaching each element on the array surface is calculated. Then, according to the target beam direction of the reflective array, the outgoing wavefront direction is determined and the outgoing phase required for each element is calculated. The difference between the incident and outgoing phases of the reflective array element is calculated, and the change in the input and output phases of each element position on the reflection surface is solved.

[0073] like Figure 5 As shown in the figure, according to the relative position between the feed source and the array element in the Cartesian coordinate system, the phase value of each incident point of the reflection array element on the reflection array is obtained:

[0074]

[0075] Where: k = 2π / λ is the wave vector of electromagnetic wave propagation in free space, (i, j) represents the grid point position at the i-th row and j-th column, the array element period is p, and the feed source position is (x 0 ,y 0 ,z 0 ).

[0076] Next, Figure 6 As shown in the figure, according to the outgoing beam direction, combined with the two-dimensional phased array beam synthesis theory, the outgoing phase of each array element is calculated. Each array element on the array plane can be equivalent to an isotropic point source with the same amplitude and fixed phase difference. Direction, the element emission phase can be expressed as:

[0077] Therefore, the difference between the reflected phase and the incident phase of each array element is:

[0078]

[0079] The difference between the reflected phase and the incident phase is the reflected phase that needs to be compensated. It can be seen from the formula that the reflected phase that needs to be compensated is a frequency-dependent value. In traditional methods, a single-frequency phase calculation method is often used to compare the reflected phase that needs to be compensated with the simulated reflected phase of a certain frequency. In fact, in a wide band, due to the difference in the wave path of different frequency bands, the reflected phase of each frequency point is not the same, resulting in a large phase error and low gain and aperture efficiency.

[0080] (2) Calculate the equivalent reflection length distribution of each unit: Based on the concept of equivalent reflection length proposed when designing the unit, the theoretical equivalent reflection length distribution of the array surface can be calculated:

[0081]

[0082] In the unit simulation, the length of the phase delay line is selected as the characteristic parameter, so the reflection phase obtained by the unit simulation can be expressed as At the same time, according to the calculation formula in (1), the unit reflection phase is converted into an equivalent length value

[0083] When using the equivalent reflection length to calculate the structural parameters of each unit, it is necessary to compare the theoretical equivalent reflection length with the equivalent length value obtained by simulation calculation to determine the phase delay line length of each unit. The theoretical equivalent reflection lengths of each frequency point calculated are equal, but because the unit structure is not an ideal non-frequency-variable structure, the equivalent reflection lengths of each frequency point obtained according to the simulation results are not the same. Therefore, when performing calculations, it is necessary to comprehensively optimize the equivalent lengths of each frequency point. Figure 7 The equivalent reflection length at each frequency point and the average value obtained from the unit simulation results are shown.

[0084] (3) Comprehensive method of equivalent reflection length at each frequency point optimized by PSO:

[0085] In order to integrate the equivalent length values ​​of different frequencies in unit simulation, the equivalent length after integration is introduced:

[0086]

[0087] in:

[0088]

[0089] like Figure 8 As shown, the weight of each frequency point ω i As the parameter to be optimized. First, according to the N frequency points in the ultra-wideband range, the particle dimension to be optimized is determined to be N. In this algorithm, the 7 frequency points in the 4-10GHz frequency band with a step of 1GHz are integrated, and the particle dimension N is 7; the population size M is set to 20, and M particles are randomly dropped in the solution space in each iteration; the particle speed v i The range is [-v max ,v max ]; The number of iterations is set to 200. After the optimization algorithm reaches the 200th time, the calculation stops and the current optimal solution is output.

[0090] The particle fitness function is the mean of the maximum phase error of the array unit at each frequency point and variance s 2 error , the smallest and 2 errorAs the optimization target. The best solution in each iteration of the particle swarm is stored in the pbest parameter, and the best solution of all particles is stored in the gbest parameter. After reaching the maximum number of iterations, the optimal weight combination is output.

[0091] like Fig. 9 and Fig.10 As shown in the figure, by comparing the equivalent reflection length synthesis method based on the PSO algorithm with the conventional single-frequency point phase calculation method, it can be seen that the phase errors of the seven frequency points have been effectively reduced.

[0092] like Fig.11 and Fig.12 As shown, the reflection bandwidth expansion effect of the ultra-wideband unit is shown. When the unit is simulated using periodic boundary conditions, it can be found that the amplitude of the reflection coefficient is greater than -0.3dB and the linearity of the reflection phase is good.

[0093] like Fig.13 As shown, the S parameter simulation results of the feed antenna 1 are shown. The S parameter amplitude simulation results of the feed antenna 1 are all lower than -10dB.

[0094] The gain and radiation pattern of the array are simulated. The radiation patterns of the 4-10GHz array with Phi = 0° and Phi = 90° are as follows: Fig.14 and 15 As shown, Fig.14 Where Phi = 0°, the radiation patterns at each frequency point are (a) 4 GHz, (b) 5 GHz, (c) 6 GHz, (d) 7 GHz, (e) 8 GHz, (f) 9 GHz and (g) 10 GHz. Fig.15 Phi = 90°, the radiation patterns at each frequency point are (a) 4GHz, (b) 5GHz, (c) 6GHz, (d) 7GHz, (e) 8GHz, (f) 9GHz and (g) 10GHz. The curves of the maximum gain and aperture efficiency of the array changing with frequency are shown in Fig.16 and 17 As shown, the array gains are all above 18dBi and the aperture efficiencies are all greater than 38%.

[0095] The present invention works in C band and X band, the unit reflection coefficient has an amplitude greater than -0.3dB in 4-10GHz, the reflection coefficient amplitude of the feed antenna is less than -10dB, and in the working frequency band of 4-10GHz, the gain of the planar reflectarray antenna is greater than 18dBi, and the aperture efficiency is greater than 38%.

[0096] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. An ultra-wideband high aperture efficiency planar reflectarray antenna, Features: It comprises a reflective array (2) and a feed antenna (1) suspended directly above the reflective array (2); the reflective array is composed of a plurality of ultra-wideband units distributed in an array; the ultra-wideband unit comprises a first dielectric substrate (3), a metal floor (7) and a vertical dielectric substrate (5); a butterfly-shaped wide-arm dipole (4) is printed on the front of the first dielectric substrate (3), and a first rectangular hole (8) penetrating the first dielectric substrate (3) is arranged at the center of the wide-arm dipole (4); a phase delay line (6) in the form of a rectangular patch is printed on both sides of the vertical dielectric substrate (5); a second rectangular hole (9) penetrating the metal floor (7) is arranged in the middle of the metal floor (7); the vertical dielectric substrate (5) passes through the second rectangular hole (9) and the first rectangular hole (8) and is electrically connected to the wide-arm dipole (4); The size of the first rectangular hole (8) is the same as that of the vertical dielectric substrate (5) and smaller than that of the second rectangular hole (9); the vertical dielectric substrate (5) passes through the second rectangular hole (9) without contacting the metal floor (7), and penetrates the first rectangular hole (8) so that the phase delay line (6) is electrically connected to the wide arm dipole (4); and the reflection phase of the ultra-wideband unit is adjusted by adjusting the phase delay line.

2. The ultra-wideband high aperture efficiency planar reflectarray antenna according to claim 1, Features: The feed antenna (1) comprises a second dielectric substrate (11), and logarithmic periodic structure antennas (10) are printed on both the front and back surfaces of the second dielectric substrate (11), and the logarithmic periodic structure antennas (10) printed on the front and back surfaces are symmetrical to each other.

3. A method for adjusting the reflection phase consistency in a wideband of an ultra-wideband high-aperture efficiency planar reflectarray antenna according to claim 1 or 2, Features: The method comprises: Optimization algorithm step: passing the given initial values ​​of the ultra-wideband unit structural characteristic parameters that need to be optimized to the simulation modeling step; Simulation modeling steps: adding variables, automatically modeling, setting boundary conditions and material parameters, setting ports, configuring solution frequencies and scanning parameters by calling library functions, scanning the length of the phase delay line (6) to obtain a curve of the reflection phase at different frequency points changing with the length L of the phase delay line (6) and exporting it to the data processing step; Data processing step: finding the equivalent reflection length and phase delay line (6) length curves at each frequency point, then finding the mean of all curves, and then finding the sum of the variances of each curve and the mean curve and passing it back to the optimization algorithm step; The data processing steps specifically include: According to the calculation formula of equivalent reflection length, the curve of equivalent reflection length changing with L at each frequency point is obtained; Then, the mean of all the curves is calculated, and the equivalent phase length of each frequency point and the length of the phase delay line (6) are compared with the mean curve, and the sum of the variances vL of all the curves is calculated, and vL is used as an indicator to judge the consistency of the reflection phase in a wide frequency band; The value of vL is passed back to the optimization algorithm step as a basis for judging the convergence of PSO; The optimization algorithm steps specifically include: Inputting the initial values ​​of the structural characteristic parameters of the ultra-wideband unit into the simulation modeling step; Determine whether the sum of variances vL returned by the data processing step meets the convergence condition. If the sum of variances vL is less than the set convergence value, the optimization is terminated and the optimized feature parameters are output; If the sum of the variances vL is greater than the set convergence value, a new set of characteristic parameters is generated according to the iteration method of the particles and the simulation modeling step and the data processing step are repeated until the sum of the variances vL returned is less than the set convergence value.

4. The method for calculating the array phase distribution of an ultra-wideband high aperture efficiency planar reflectarray antenna according to claim 1 or 2, Features: The calculation method includes: Calculate the reflection phase that needs to be compensated for each ultra-wideband unit distributed in the array; Calculate the equivalent reflection length distribution of each ultra-wideband unit according to the equivalent reflection length; The PSO algorithm is used to comprehensively optimize the equivalent reflection length of each frequency point to obtain the phase distribution of the optimal weight combination; The calculation of the reflection phase that needs to be compensated for each ultra-wideband unit distributed in the array includes: The phase center of the feed antenna (1) is equivalent to an ideal point source, and the incident phase of the spherical wave radiated by the point source arriving at each ultra-wideband unit on the array plane, i.e., the array element, is calculated; According to the target beam direction of the reflective array (2), the outgoing wavefront direction is determined and the outgoing phase required by each ultra-wideband unit is calculated; Calculate the difference between the incident and outgoing phases of each element in the reflective array (2), and solve for the input and output phase change value of each ultra-wideband unit position on the reflective surface; According to the relative position between the feed source and the ultra-wideband unit in the Cartesian coordinate system, the phase value of each element incident point on the reflective array (2) is obtained: ,in, is the wave vector of electromagnetic wave propagating in free space, Indicates Row, No. The grid point position at the column, the array element period is , the feed position is ; According to the outgoing beam direction and combined with the two-dimensional phased array beam synthesis theory, each array element on the reflective array (2) is equivalent to an isotropic point source with the same amplitude and fixed phase difference. Direction, calculate the array element outgoing phase ; Then the difference between the reflected phase and the incident phase of each array element is calculated, that is, the compensated reflected phase is: 。 5. The method for calculating the array phase distribution of an ultra-wideband high aperture efficiency planar reflectarray antenna according to claim 4, Features: The PSO algorithm is used to comprehensively optimize the equivalent reflection length of each frequency point to obtain the phase distribution of the optimal weight combination, including: The weight of each frequency point As the parameter to be optimized, according to the ultra-wideband range The frequency points to be solved are determined to be the particle dimensions that need to be optimized. ; Initialize the particle position and particle velocity, and calculate the average of the maximum phase error of the array element at each frequency point and variance Detect as a particle fitness function and update particle velocity and particle position; The smallest and As the optimization target, the best solution in each iteration of the particle swarm is stored in the pbest parameter, and the best solution of all particles is stored in the gbest parameter. After reaching the maximum number of iterations, the optimal weight combination is output.

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