CN112151969A - In-band RCS Control Method for Strongly Coupled Broadband Phased Array Based on Generalized Scattering Matrix - Google Patents

Abstract

The invention belongs to the technical field of antenna engineering and discloses an in-band RCS control method for a strong coupling broadband phased array. The method is mainly based on generalized scattering matrix to quickly predict the radiation and scattering characteristics of the strong coupling broadband phased array after different matching circuits are connected between each unit port of the strong coupling broadband phased array antenna and a feed network, the terminated matching circuits are used as optimization variables, meanwhile, the radiation performance and the scattering performance of the array are optimized, and finally, the reduction of the RCS in the band of the strong coupling broadband phased array antenna is realized on the premise that the radiation characteristics are kept good. The invention can accurately estimate the radiation and scattering characteristics of the strong coupling broadband phased array after terminating the matching circuit, considers the factors which have larger influence on the radiation and scattering characteristics in the limited large array, solves the problem of reducing the in-band RCS of the broadband phased array antenna when the coupling effect is intentionally enhanced between array elements, and can effectively control the in-band RCS in the strong coupling broadband phased array while keeping good radiation performance.

Description

In-band RCS Control Method for Strongly Coupled Broadband Phased Array Based on Generalized Scattering Matrix

technical field

The invention belongs to the technical field of antenna engineering, and in particular relates to an in-band RCS control method for a strongly coupled broadband phased array antenna.

Background technique

Phased array antenna is the main antenna type of modern radar system due to its advantages of fast beam scanning speed, high tracking accuracy and strong anti-jamming ability. With the requirements of high integration of modern combat platforms, phased array antenna technology is developing in the direction of broadband design to adapt to the integrated electronic system integrating electronic reconnaissance, electronic interference, radar detection, wireless communication and other functions. . The traditional broadband phased array antenna design is generally based on the idea of "first broadband unit and then array", the coupling effect between the array elements is regarded as a disadvantage, this design method is very limited in expanding the bandwidth of the phased array antenna. . In recent years, a new concept technology of broadband phased array antenna design based on strong coupling effect has been proposed in the field of international antenna research. Different from the traditional design idea of broadband antenna array, the strong coupling broadband phased array takes the coupling effect between the array elements as a favorable factor and is deliberately strengthened when designing the unit, so that the original discrete distribution array becomes similar to the continuous distribution. "Current layer", and the input impedance characteristic at each feeding node of this "current layer" becomes slower with frequency, thereby realizing the broadband characteristic of the antenna array.

In order to meet the high stealth requirements of modern combat carrier platforms (such as aircraft, missiles, ships, etc.) at the same time, as an indispensable component of stealth carrier platforms, phased array antennas are increasingly required to have lower RCS (radar crosssection, Radar Cross Section) characteristics to improve the survivability of our combat weapons and equipment. At present, most of the technical research on antenna RCS reduction mainly focuses on single antenna, mainly by adopting 1) changing the antenna shape; 2) absorbing materials; 3) electromagnetic metamaterials and other methods to achieve the RCS reduction of the antenna. A few literatures have studied the scattering characteristics of antenna arrays, but most of them are limited to the reduction of the scattering characteristics of the array elements, and the scattering characteristics are not considered from the perspective of array synthesis.

In the patent with the patent number of CN201610038643, a method for reducing the in-band RCS of a phased array antenna is proposed by randomly rotating the array elements around the feeding point. The random rotation of the array elements is used to generate random scattering phases, so that the The scattered fields cannot be superimposed in phase in a main lobe area, but will be dispersed into a wider angular domain space, thereby reducing the RCS of the array antenna. At the same time, in the case of radiation, the phase compensation of the array element excitation can still achieve in-phase superposition of the radiation fields of different array elements in the main lobe area, so that the radiation performance of the array antenna will not be degraded. However, this patent does not disclose the fact that this method is only applicable to the fact that the polarization form of the antenna element is circular polarization, otherwise the random rotation of the array elements will definitely change the polarization state of each array element, resulting in the deterioration of the array radiation performance after the superposition of different array elements. In addition, this design method only considers the ideal situation in the infinite array environment, and does not comprehensively design the scattering characteristics of the actual finite array. In the patent No. CN201810738594, a reconfigurable phased array antenna RCS reduction method based on scattering polarization is provided. Each array element of the phased array antenna includes three different polarization modes. When the antenna radiates, all the array elements are in the same polarization mode to form a unified polarization array. After the phased array antenna radiation is completed, the polarization modes of each array element are randomly distributed to form a random polarization array, which can achieve On the basis of not affecting the radiation performance of the array antenna, the RCS after the end of the array antenna radiation is significantly reduced. In this method, the polarization states of the array elements in the radiation and scattering states are independently set. Each array element needs to be controlled by switching on and off the PIN diode, and additional external control processing to control the polarization mode of the array element is required. It increases the complexity of the system. In addition, this design method also has great limitations in the selection of antenna forms and the application of broadband phased arrays. In order to control the in-band RCS, in 2011, Dr. Wang Wentao from Xidian University in his doctoral dissertation "Research on the Analysis and Control Method of Antenna Radar Cross Section" proposed a method for reducing the RCS of the mode term of the symmetric oscillator array antenna. However, the overall scattering properties of the array are not considered.

It is undeniable that because the radiation performance and low scattering performance of the antenna are often a pair of contradictions that are difficult to reconcile, these technical means are difficult to be used for the RCS control of the broadband phased array antenna. At this stage, the RCS control method of the broadband phased array antenna is concerned. It is still in the research stage, and related theories and technologies are relatively lacking. The research reports on how to achieve effective in-band RCS control under the premise of ensuring that the radiation performance of the phased array antenna in the working frequency band is basically unchanged are extremely limited. Further, considering the challenges faced by traditional broadband phased array antenna technology, the new phased array antenna design technology based on strong coupling effect has natural advantages in broadband characteristics. The research on internal RCS control is more helpful to promote the development of a new generation of stealth carrier platform broadband phased array antenna technology. As far as the existing disclosed technical means for in-band RCS control of strongly coupled broadband phased array antennas are concerned, the patents with patent application numbers CN201810200308 and CN201710288813 both adopt the structure of the strongly coupled broadband phased array antenna unit itself. The processing method attempts to reduce the scattering of the antenna mode item of the unit by improving the in-band impedance matching characteristics, thereby achieving the purpose of suppressing the in-band RCS of the array. Because this method only focuses on the scattering control at the antenna unit level, and does not introduce the idea of array synthesis, it is not easy to apply to any other structural type of array, and the versatility is poor.

In a finite array, it is impossible to guarantee that the actual array environment of each unit is exactly the same, especially the difference between the edge unit and the center unit is obvious. Traditional phased arrays generally take additional measures to reduce the coupling between units, and try to make the electromagnetic environment of each unit the same. However, the electromagnetic environment of each element of a strongly coupled broadband phased array designed to enhance the coupling effect between array elements is quite different, and the impedance mismatch of individual elements cannot be avoided, and the scattering characteristics of the array may also deteriorate. In addition, due to the finite size of any finite array, the truncation effect of the edge, the excited surface wave and the diffraction of the electromagnetic wave at the discontinuity will all affect the electromagnetic radiation and scattering characteristics. Based on the above application requirements, the present invention proposes a method for reducing the in-band RCS of a strongly coupled broadband phased array from the perspective of array synthesis based on the generalized scattering matrix theory. The characteristics are basically not degraded.

SUMMARY OF THE INVENTION

In view of the above background, the purpose of the present invention is to propose an in-band RCS control method for a strongly coupled broadband phased array antenna in order to overcome the deficiencies of the prior art. Due to the close arrangement of the strongly coupled broadband phased array antenna elements, the ultra-wideband impedance matching characteristics are obtained by introducing the strong coupling effect to form a uniform and continuous current distribution on the array surface. In this case, the impedance mismatch of the excitation ports of the individual units of the strongly coupled finite array will inevitably occur, causing the scattering characteristics of the array to deteriorate; in addition, the edge truncation effect, surface waves and the diffraction of electromagnetic waves at discontinuities will all lead to Contributing to the RCS of the array. In order to solve this dilemma, the present invention proposes a strong coupling broadband phased array in-band RCS control method based on the generalized scattering matrix theory, using the generalized scattering matrix theory to design different matching circuits for each element in the array, and realize the realization from the perspective of array synthesis. In-band RCS reduction for phased arrays.

The technical scheme of the present invention is: a strong coupling broadband phased array in-band RCS control method based on generalized scattering matrix theory, the schematic diagram of the topology structure is shown in Figure 1, and includes the following steps:

Step 1: Build a strongly coupled broadband phased array, and extract the generalized scattering matrix G of the strongly coupled broadband phased array. The expression of the generalized scattering matrix is as follows:

In the formula: Γ represents the reflection parameter matrix of the antenna excitation port, R represents the receiving parameter matrix of the antenna in the receiving state, T represents the transmitting parameter matrix of the antenna in the transmitting state, S represents the reflection coefficient on the antenna front when the electromagnetic wave is incident, and I is unit array;

Step 2: Design a different matching circuit for each unit, and extract the scattering parameter matrix K _i of the matching circuit of the ith unit; or use the idea of an equivalent circuit to quickly calculate the scattering parameter matrix of the matching circuit, the expression of K _i The formula is as follows:

与

分别代表第i个单元其匹配电路中其他所有端口接匹配负载时端口1或端口2的反射系数，

是指第i个单元其匹配电路中其他所有端口接匹配负载时从端口2至端口1的传输系数，

是指第i个单元其匹配电路中其他所有端口接匹配负载时从端口1至端口2的传输系数；In the formula: K _i is the S-parameter matrix of the matching circuit of the i-th unit,

and

respectively represent the reflection coefficient of port 1 or port 2 when all other ports in the matching circuit of the i-th unit are connected to matching loads,

Refers to the transmission coefficient from port 2 to port 1 when all other ports in the matching circuit of the i-th unit are connected to the matching load,

Refers to the transmission coefficient from port 1 to port 2 when all other ports in the matching circuit of the i-th unit are connected to the matching load;

Step 3: Use the comprehensive prediction expression to predict the generalized scattering parameter matrix G _m of the strong coupling broadband phased array after each element in the strong coupling broadband phased array is terminated with a different matching circuit, and the comprehensive prediction expression of the generalized scattering matrix The formula is as follows:

Step 4: Using the calculated generalized scattering parameter matrix G _m , the active standing wave and single-station/dual-station RCS of the strongly coupled broadband phased array can be easily calculated;

Step 5: Combine the global optimization algorithm to optimize the matching circuit terminated by each unit, and design a new strong-coupling broadband phased array. Compared with the original array, the single-station/dual-station RCS is significantly reduced, while ensuring that its radiation characteristics are not affected. deterioration;

Step 6: In the simulation model, the optimized matching circuits of each unit are terminated to the corresponding units, and the final optimized model is simulated by full-wave electromagnetic simulation software to verify the predicted radiation and scattering characteristics;

Step 7: Extract the active pattern of the final optimization model and the passive scattering parameter matrix of the excitation port, and use the global optimization algorithm to optimize the amplitude and phase of each element excitation to improve the achievable gain of the phased array;

The generalized scattering matrix comprehensive prediction expression in step 3 completely considers the coupling effect between the excitation ports after each unit is terminated with different matching circuits, and is an accurate generalized scattering matrix prediction expression analytical expression;

In step 4, the active standing wave of each element in the strongly coupled broadband phased array can be obtained by using the Γ _m in the generalized scattering parameter matrix G _m through the active reflection coefficient synthesis formula;

In general, the general technical scheme of the present invention is as follows: based on the generalized scattering matrix theory, the matching network connected between each unit port of the strong coupling broadband phased array antenna and the feeding network is optimized by comprehensive prediction, and by realizing the Good impedance matching reduces the RCS of the mode term or makes the mode term and the structural term energy cancel in the expected scattering direction, which significantly reduces the RCS of the strongly coupled broadband phased array. In the optimization process, in order to achieve a balance between the radiation performance and the low scattering performance of the array, it is necessary to set the optimization target reasonably, in order to obtain a better optimization effect. Ultimately, it is desirable to achieve antenna arrays with lower RCS without significantly degrading the radiation characteristics.

The innovation of the invention lies in that it proposes a strong coupling broadband phased array antenna RCS control method based on the generalized scattering matrix theory, and accurately predicts that each element of the strong coupling broadband phased array has different terminations through the comprehensive prediction expression of the generalized scattering matrix. The generalized scattering matrix after the matching circuit takes into account factors such as finite array truncation effect, surface wave excitation, and electromagnetic wave diffraction at discontinuities, so as to achieve accurate prediction of radiation and scattering characteristics of strongly coupled broadband phased arrays. Based on the above theoretical basis, combined with a global optimization algorithm to optimize the termination matching circuit of each unit and the excitation amplitude and phase of each excitation port, the RCS reduction is finally achieved while keeping the radiation characteristics from being deteriorated. At the same time, the present invention has the following unique features:

1. Based on the generalized scattering matrix theory, a comprehensive prediction expression of the generalized scattering matrix is proposed to realize the accurate prediction of radiation and scattering characteristics after each element of the strongly coupled broadband phased array is terminated with a matching network, considering the truncation of the finite array effects, surface wave excitation, and electromagnetic wave diffraction at discontinuities caused by finite size.

2. Different from the numerical analysis method, the application of this formula can save the amount of calculation, improve the calculation efficiency, and can quickly process the array with a large number of units, which has certain value for the rapid analysis of the radiation and scattering characteristics of the array antenna;

The beneficial effects of the present invention are as follows: the present invention can significantly reduce the in-band RCS of the strongly coupled broadband phased array antenna under the condition that the radiation performance of the array is not substantially deteriorated. Compared with the prior art, the present invention solves the problem of in-band RCS reduction of broadband phased array antennas when there is an intentionally enhanced coupling effect between array elements, and the proposed method takes into account the surface wave effect in a finite array. , truncation effect and edge diffraction, can accurately predict the radiation and scattering characteristics of a finite array after each unit is terminated with a matching circuit, and can also be used for radiation and scattering after a strongly coupled broadband phased array is terminated with a feed network. Prediction of properties. Accurate synthetic estimation expressions allow for minimal time and computer resources per iteration during the optimization process. Therefore, the present invention can rapidly predict and optimize the radiation and scattering characteristics of a strongly coupled broadband phased array with thousands of elements. In addition, the proposed method has very good universality for the effective control of in-band RCS under the premise that the radiation performance of phased array antennas with broadband characteristics at any frequency point in the band is kept good.

Description of drawings

Fig. 1 is a schematic diagram of the topology of the technical solution of the present invention

FIG. 2 is a schematic diagram of a model of a 1×16 finite-strong-coupling broadband phased array antenna array (original array) operating at 8.0-10.0 GHz in the specific embodiment provided by the present invention;

3 is a schematic diagram of a model of a strongly coupled broadband phased array antenna unit operating at 8.0-10.0 GHz in the specific embodiment provided by the present invention;

Figure 4 shows the single-station RCS of the 1x16 finite and strong coupling broadband phased array under the vertical incidence of the co-polar incident wave obtained by calculation and simulation after the strong coupling array in Example 1 is terminated with a set of random loads;

Fig. 5 shows the active standing waves of the center unit and the edge units on both sides of the 1x16 finite and strong coupling broadband phased array obtained by calculation and simulation after the strong coupling array in Example 1 is terminated with a set of random loads;

Figure 6 shows the dual-station RCS of a 1x16 finite-strong-coupling broadband phased array at 9.0 GHz under vertical incidence of co-polarized incident waves obtained through calculation and simulation after the strong-coupling array in Example 1 is terminated with a set of random loads. ;

Fig. 7 is the radiation far-field electric field diagram at 9.0 GHz of the 1x16 finite and strong coupling broadband phased array obtained by calculation and simulation after the strong coupling array is terminated with a set of random loads in Example 1;

8 is a schematic diagram of a 1×16 limited-strong-coupling broadband phased array (optimized array) model in which an optimized group of coaxial cavities are loaded on an antenna excitation port in Embodiment 2;

9 is a comparison diagram of the actual full-wave simulation performance of the single-station RCS under the vertical incidence of the co-polarized incident wave of the metal floor, the original array and the optimized array in Example 2;

10 is a comparison diagram of the actual full-wave simulation performance of the dual-station RCS on the yoz plane under the normal incidence of the co-polarized incident wave at 9.0 GHz on the metal floor, the original array and the optimized array in Example 2;

11 is a comparison diagram of the actual full-wave simulation performance of the double-station RCS on the xoz plane under the normal incidence of the co-polarized incident wave at 9.0 GHz on the metal floor, the original array and the optimized array in Example 2;

12 is a comparison diagram of the full-wave simulation results of the active standing wave of the central unit when the original array and the optimized array are side-fired and scanned at 45° in Example 2;

13 is a comparison diagram of the full-wave simulation results of the gain that can be achieved when the original array and the optimized array are side-fired in Example 2;

14 is a comparison diagram of the full-wave simulation results of the gain scanning pattern of the original array and the optimized array in Embodiment 2;

Detailed ways

The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings.

As shown in Figure 2 and Figure 3, taking a strongly coupled broadband phased array antenna working in the X-band as an example, its antenna array 1 consists of N strongly coupled broadband phased array antenna units 2, where N is the number of array elements The number, of course, is not limited to the 1×16 array elements shown in FIG. 2 , and may even be in the form of a plane array arrangement. The strongly coupled broadband phased array antenna units 2 are evenly arranged along the main polarization direction of the antenna, that is, the y-direction is equally spaced, and the spacing does not exceed λ/2 (λ is the corresponding high-frequency wavelength). The phased array antenna elements 2 are closely arranged, and there is a deliberately enhanced coupling effect between the elements. It should be mentioned that in the specific implementation manner, the strongly coupled broadband phased array antenna element model shown in FIG. 2 and FIG. 3 is only used as an example, and is not limited to the structure of the array element, and is familiar with the engineering technology in the field Personnel can use any other form of phased array unit to replace according to actual needs. In order to control the in-band RCS of the strongly coupled broadband phased array antenna, a matching circuit 3 is loaded between each element port of the strongly coupled broadband phased array antenna and the feed network/load. The open coaxial cavity is used as a matching circuit, and those skilled in the art can use any other form of matching circuit to replace it according to actual needs. Taking the matching circuit as the optimization variable, the comprehensive prediction expression of the generalized scattering matrix is used in conjunction with the differential evolution algorithm (not limited to this algorithm, and engineers and technicians familiar with the field can choose any other intelligent optimization algorithm according to actual needs), and at the same time, the array is optimized. The radiation performance and scattering performance are optimized, so that the RCS peak value of the antenna mode term is shifted out of the maximum radiation direction of the array, so as to realize the scattering control in the designated threat airspace within the operating frequency band of the array antenna.

Example 1: Validation of Generalized Scattering Matrix Theory Method

Specifically, a set of impedances are randomly terminated at the ports of a 1×16 strongly coupled finite phased array (as shown in Figure 1), and the radiation and scattering characteristics of the array are predicted by the generalized scattering matrix theory method, and the simulation results of commercial electromagnetic simulation software For comparison: the single-station RCS curves calculated and simulated at 8GHz-10GHz are shown in Figure 3, Figure 4 shows the active reflection coefficients of the center unit and the left and right edge units when side-emitting, and Figure 5 shows the center frequency The dual-station RCS curve at 9.0GHz, and finally Figure 6 gives the array radiation far-field at the center frequency of 9.0GHz. It can be seen from the above pictures that the single-station RCS, double-station RCS, active reflection coefficient and radiation far-field pattern predicted and calculated by the generalized scattering matrix theory method proposed in this patent are basically consistent with the simulation results of commercial electromagnetic simulation software. The effectiveness of this method is verified.

Example 2: 1×16 limited, large and strong coupling broadband phased array antenna RCS optimization and comprehensive control

Specifically, when the 8GHz-10GHz main polarization incident wave is vertically irradiated on the array antenna 1, the single-station/dual-station RCS optimization synthesis problem of the array antenna is considered. The length and characteristic impedance of the coaxial cavity 3 obtained by the final optimization and loaded on the excitation port of the 1×16 strong coupling broadband phased array are shown in Figure 7. The comparison of the single-station/dual-station scattering performance results of the array antenna before and after optimization are shown in 8 to 10. It can be seen from Figure 9 that the optimized array has lower scattering characteristics in the entire operating frequency band than the original array, and achieves at least 5dB reduction in RCS at 8.25GHz–10.0GHz. Compared with the metal floor of the same physical area, the optimized array achieves at least 10dB RCS reduction in the whole frequency band, and the scattering control effect is remarkable. It can be seen from Figures 9 and 10 that the dual-station RCS characteristics of the optimized array are also significantly reduced. The active standing wave of the array before and after optimization is shown in Figure 11. It can be seen from the figure that the active standing wave of the optimized array is still less than 3.0, which meets practical engineering applications. Figure 12 shows the achievable gain of the array before and after optimization. It can be seen from the figure that the achievable gain of the optimized array is basically not reduced compared to the reference array, and the maximum gain reduction value is only 0.5dB, and at the center frequency band Gain slightly increased. The 0° and 45° scanning patterns of the optimized array at the center frequency of 9.0 GHz are shown in Figure 13. It can be seen that the optimized array pattern points well and has no distortion.

To sum up, the technical means proposed in the present invention can significantly reduce the single-station RCS of the strongly coupled broadband phased array in the broadband range, and basically maintain its radiation characteristics.

The foregoing is a description of the preferred embodiments of the present invention and specific embodiments thereof provided to those skilled in the art of the invention, and it should be noted that these descriptions are to be regarded in an illustrative rather than a restrictive sense. For engineers and technicians in the field, without departing from the principle of the present invention, according to the central idea of the present invention, combined with specific problems, specific operation implementation, several improvements and modifications can also be made. Naturally, it can also be based on the above Make a series of changes to the implementation. The above contents should also be regarded as the protection scope of the present invention.

Claims (3)

1. the in-band RCS control method of the strong coupling broadband phased array based on generalized scattering matrix, is characterized in that, comprises the following steps: Step 1: Build a strongly coupled broadband phased array, and extract the generalized scattering matrix G of the strongly coupled broadband phased array. The expression of the generalized scattering matrix is as follows:

In the formula: Γ represents the reflection parameter matrix of the antenna excitation port, R represents the receiving parameter matrix of the antenna in the receiving state, T represents the transmitting parameter matrix of the antenna in the transmitting state, S represents the reflection coefficient on the antenna front when the electromagnetic wave is incident, and I is unit array; Step 2: Design a different matching circuit for each unit, and extract the scattering parameter matrix K _i of the matching circuit of the ith unit; or use the idea of an equivalent circuit to quickly calculate the scattering parameter matrix of the matching circuit, the expression of K _i The formula is as follows:

In the formula: K _i is the S-parameter matrix of the matching circuit of the i-th unit,

and

respectively represent the reflection coefficient of port 1 or port 2 when all other ports in the matching circuit of the i-th unit are connected to matching loads,

Refers to the transmission coefficient from port 2 to port 1 when all other ports in the matching circuit of the i-th unit are connected to the matching load,

Refers to the transmission coefficient from port 1 to port 2 when all other ports in the matching circuit of the i-th unit are connected to the matching load; Step 3: Use the comprehensive prediction expression to predict the generalized scattering parameter matrix G _m of the strong coupling broadband phased array after each element in the strong coupling broadband phased array is terminated with a different matching circuit, and the comprehensive prediction expression of the generalized scattering matrix The formula is as follows:

Step 4: Using the calculated generalized scattering parameter matrix G _m , the active standing wave and single-station/dual-station RCS of the strongly coupled broadband phased array can be easily calculated; Step 5: Combine the global optimization algorithm to optimize the matching circuit terminated by each unit, and design a new strong-coupling broadband phased array. Compared with the original array, the single-station/dual-station RCS is significantly reduced, while ensuring that its radiation characteristics are not affected. deterioration; Step 6: In the simulation model, the optimized matching circuits of each unit are terminated to the corresponding units, and the final optimized model is simulated by full-wave electromagnetic simulation software to verify the predicted radiation and scattering characteristics; Step 7: Extract the active pattern of the final optimization model and the passive scattering parameter matrix of the excitation port, and use the global optimization algorithm to optimize the amplitude and phase of each element excitation to improve the achievable gain of the phased array; In step 4, the active standing wave of each element in the strongly coupled broadband phased array can be obtained by using the Γ _m in the generalized scattering parameter matrix G _m through the active reflection coefficient synthesis formula. 2. the in-band RCS control method of the strong coupling broadband phased array based on generalized scattering matrix according to claim 1, it is characterized in that, the comprehensive estimation expression of generalized scattering matrix in step 3 has fully considered each unit end The coupling effect between the excitation ports after connecting different matching circuits is an accurate analytical expression for predicting the generalized scattering matrix. 3. the in-band RCS control method of the strong coupling broadband phased array based on generalized scattering matrix according to claim 1, it is characterized in that, this method is for the phased array antenna with broadband characteristic in-band radiation performance at any frequency point The effective control of in-band RCS under the premise of maintaining good performance has very good universality.

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