Metasurface antenna capable of suppressing high-order mode and enhancing directional radiation

Abstract

The invention relates to a metasurface antenna for suppressing high-order mode and enhancing directional radiation. The metasurface antenna comprises a bottom plate; the dielectric substrate is arranged on the upper surface of the bottom plate; the main array is formed by periodically arranging a plurality of metal patches at intervals and is arranged on the upper surface of the dielectric substrate; the auxiliary patches are arranged on the upper surface of the dielectric substrate and located on the periphery of the main array, and resistive elements are loaded on the auxiliary patches; the feed structure penetrates through the bottom plate and the dielectric substrate, is electrically connected with the main array and is used for exciting the main array; by introducing the lossy partner unit composed of the auxiliary patch and the resistive element, harmful high-order mode radiation is selectively coupled and dissipated on the premise that the main array and the feed structure are not changed, and meanwhile the needed directional radiation performance is reserved and enhanced; the problem that the directional radiation performance of the metasurface antenna is reduced due to high-order mode interference is fundamentally solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of super surface antenna, in particular to a super surface antenna for suppressing high-order mode and enhancing directional radiation. BACKGROUND

[0002] In the field of modern communication, radar detection, etc., super surface array antenna has great application potential in modern wireless communication, radar detection, etc. due to its low profile, low loss, easy integration and high design freedom. Through careful design of the unit structure, the super surface can flexibly control the phase, amplitude, polarization and other parameters of electromagnetic waves, thereby improving the antenna gain and compressing the beam width.

[0003] However, in practical applications, especially in super surface arrays with closely arranged units, multiple high-order modes will inevitably be excited. These unnecessary high-order modes will interfere with the required basic mode, causing serious distortion in far-field radiation, such as main lobe tilt, beam splitting and high side lobe level. These distortions significantly reduce the directional radiation capability and signal transmission quality of the antenna, limiting its use in mobile application scenarios. SUMMARY

[0004] The present application aims to overcome the defects of the prior art and provide a super surface antenna for suppressing high-order mode and enhancing directional radiation, solving the problem of directional radiation performance degradation caused by high-order mode interference in the prior art.

[0005] To achieve the above-mentioned purpose, the present application provides a super surface antenna for suppressing high-order mode and enhancing directional radiation, comprising:

[0006] a bottom plate;

[0007] a dielectric substrate arranged on the upper surface of the bottom plate;

[0008] a main array arranged on the upper surface of the dielectric substrate and formed by a plurality of metal patches arranged at periodic intervals;

[0009] at least one auxiliary patch arranged on the upper surface of the dielectric substrate and located at the periphery of the main array, the auxiliary patch being loaded with a resistive element;

[0010] a feeding structure penetrating the bottom plate and the dielectric substrate and electrically connected with the main array for exciting the main array;

[0011] wherein the auxiliary patch interacts with the main array through electromagnetic coupling to form a partner system for suppressing high-order mode radiation of the main array and enhancing its directional radiation performance.

[0012] By adopting the technical scheme, on the basis of the bottom plate, the dielectric substrate and the main array constituting a basic antenna, the lossy partner unit composed of the auxiliary patch and the resistive element is introduced to selectively couple and dissipate the harmful high-order mode radiation without changing the main array and the feeding structure, while the required directional radiation performance is retained and enhanced, the problem of the decline of the directional radiation performance of the metasurface antenna caused by the high-order mode interference is fundamentally solved, and the accuracy and stability of signal transmission are ensured.

[0013] Further, the auxiliary patch is the same in shape as the metal patch in the main array, but there is a size difference, and the size difference is configured to match and suppress specific high-order modes.

[0014] By adopting the technical scheme, the auxiliary patches of different sizes correspond to different resonant frequencies and mode distributions; by finely adjusting the size, one or more specific high-order modes in the main array can be accurately matched and suppressed, and the selectivity and efficiency of mode suppression are improved.

[0015] Further, the coupling distance between the auxiliary patch and the main array is adjustable, and the coupling distance is adjusted to optimize the suppression bandwidth and degree of the high-order mode.

[0016] By adopting the technical scheme, the coupling distance is a key parameter affecting the coupling strength; by adjusting the distance, the frequency band width and suppression degree of mode suppression can be optimized without replacing the element, so that the antenna can better adapt to different frequency bands or tolerance requirements.

[0017] Further, the resistance value of the resistive element loaded on the auxiliary patch is adjustable, and the resistance value is adjusted to control the dissipation degree of the high-order mode energy.

[0018] By adopting the technical scheme, the resistance value matching degree is a key to determine the energy dissipation degree; adjusting the appropriate resistance value can control the "absorption" efficiency of the high-order mode energy, realize the fine adjustment of the radiation direction, and achieve the best radiation performance.

[0019] Further, the resistive element loaded on the auxiliary patch is connected with the bottom plate through the via hole passing through the dielectric substrate to form a current dissipation path.

[0020] By adopting the technical scheme, the vertical installation provides a clear and low-impedance grounding path for the coupled high-frequency current, ensuring that the energy can be efficiently converted into heat by the resistor, thereby maximizing the suppression effect.

[0021] Further, the design of the partner system is based on supersymmetry transformation, so that the auxiliary patch is coupled with the high-order mode of the main array at the same resonance frequency, and the high-order mode energy is converted into non-radiative thermal energy dissipation, while maintaining the mode orthogonality with the fundamental mode.

[0022] By adopting this technical solution, the supersymmetry theory provides a strict mathematical framework, which can systematically design the partner system, ensure the phase matching with the high-order mode and achieve strong coupling, and realize the root optimization.

[0023] Further, the metal patches are arranged in a three-by-three square, and the auxiliary patches are arranged around the main array formed by the three-by-three square arrangement of the metal patches.

[0024] By adopting this technical solution, a symmetrical surrounding layout is formed, which can simultaneously suppress various high-order modes that may occur in the longitudinal and transverse directions, and ensure that the antenna has good directional radiation symmetry in the horizontal plane and the horizontal projection plane.

[0025] Compared with the prior art, the present application has the following advantages:

[0026] On the basis of the basic antenna composed of the bottom plate, the dielectric substrate and the main array, by introducing the lossy partner unit composed of the auxiliary patch and the resistive element, the harmful high-order mode radiation is selectively coupled and dissipated without changing the main array and the feeding structure, while the required directional radiation performance is retained and enhanced, thereby fundamentally solving the problem of directional radiation performance degradation of the metasurface antenna caused by high-order mode interference, and ensuring the accuracy and stability of signal transmission. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a top view schematic diagram of the metasurface antenna for suppressing high-order mode and enhancing directional radiation in the present application.

[0028] Figure 2 It is a vertical side view schematic diagram of the metasurface antenna for suppressing high-order mode and enhancing directional radiation in the present application.

[0029] Figure 3 It is a radiation intensity schematic diagram of the metasurface antenna device corresponding to parameter adjustment obtained by electromagnetic simulation software in the embodiment of the present application.

[0030] Figure 4 It is a schematic diagram of (a) reflectivity and (b) gain of the main axis of the main array antenna measured in the embodiment of the present application.

[0031] Figure 5 It is a schematic diagram of (a) reflectivity and (b) gain of the main axis of the optimized metasurface antenna array measured in the embodiment of the present application.

[0032] Figure 6 Fig. 1 is a schematic diagram of the far-field distribution of the optimized antenna and main array obtained by experimental measurement in the present application at 9.4, 9.6, 9.8 GHz.

[0033] Legend: 1, bottom plate; 2, dielectric substrate; 3, main array; 31, metal patch; 4, auxiliary patch; 5, resistive element; 6, feed structure. DETAILED DESCRIPTION

[0034] The present application will be further described below in conjunction with the drawings and specific embodiments.

[0035] Please refer to the accompanying Figure 1 and 2 , the present application provides a super surface antenna for suppressing high-order mode enhancement directional radiation, comprising: a bottom plate 1; a dielectric substrate 2 arranged on the upper surface of the bottom plate 1; a main array 3 composed of a plurality of metal patches 31 arranged at periodic intervals, arranged on the upper surface of the dielectric substrate 2; at least one auxiliary patch 4 arranged on the upper surface of the dielectric substrate 2 and located at the periphery of the main array 3, the auxiliary patch 4 being loaded with a resistive element 5; a feed structure 6 penetrating the bottom plate 1 and the dielectric substrate 2 and electrically connected with the main array 3, for exciting the main array 3; wherein the auxiliary patch 4 interacts with the main array 3 through electromagnetic coupling, forming a partner system for suppressing the high-order mode radiation of the main array 3 and enhancing its directional radiation performance.

[0036] On the basis of the bottom plate 1, the dielectric substrate 2 and the main array 3 constituting the basic antenna, by introducing the lossy partner unit composed of the auxiliary patch 4 and the resistive element 5 without changing the main array 3 and the feed structure 6, the harmful high-order mode radiation is selectively coupled and dissipated, while the required directional radiation performance is retained and enhanced, fundamentally solving the problem of directional radiation performance degradation of the super surface antenna caused by high-order mode interference, and ensuring the accuracy and stability of signal transmission.

[0037] Further, continuing to refer to the accompanying Figures 1-2 , in this embodiment, the super surface antenna uses F4BM-2 double-sided copper clad plate as the dielectric substrate 2, which has a dielectric constant ε r = 2.2, a loss tangent tanδ = 0.009, is square, and a thickness h = 0.018 mm, a side length W g = 50 mm;

[0038] The main array is composed of nine non-magnetic rectangular metal patches 31 (dark gray structure shown in the figure) arranged in the form of three by three; the length L p = 10.1 mm of each metal patch 31, the width W p= 5mm, the interval S of adjacent metal patches 31 in x and y directions p = 0.5mm;

[0039] The feeding structure adopts an SMA radio frequency joint, which is welded on the metal patch 31 at the center of the main array 3 through a via, and the welding point is away from the upper edge of the metal patch 31 by D = 3mm;

[0040] The auxiliary patch 4 (shown in light gray structure) is a rectangular metal patch, which has the same width as the metal patch 31 but different lengths, L1 = 9.7mm, L2 = 9.8mm, L'2 = 10mm, L3 = 9.9mm; these auxiliary patches 4 surround the three-by-three main array 3; on the top edge of each auxiliary patch 4, a packaged patch resistor with a model of 0201 is vertically installed through a via with a radius of r = 0.2mm, the resistance of which is 1MΩ, and the two ends of the resistor are welded to the bottom plate 1 and the auxiliary patch 4, respectively.

[0041] Based on the above embodiment parameters, the antenna performance is simulated and optimized by full-wave electromagnetic simulation software (CST Microwave Studio); the key optimization parameters include the coupling distance g between the auxiliary patch 4 and the main array 3 and the resistance R of the loaded resistor; as shown in Figure 3 , by optimizing these parameters, the antenna realizes stable and high-gain wide-side radiation in the frequency band of 8.5-10.5GHz;

[0042] Figures 4 to 6 The experimental measurement results verify the effectiveness of the present application; specifically, by comparing Figure 4 (a) (b) and Figure 5 (a) (b) can be seen that after introducing the partner unit (i.e. the auxiliary patch 4), the reflectivity dip of the antenna near 9.8GHz still exists, but the gain at this frequency point is greatly improved, indicating that the radiation efficiency is significantly improved; from Figure 6 the far-field pattern comparison, it can be clearly seen that at the three frequency points of 9.4GHz, 9.6GHz and 9.8GHz, the main lobe of the optimized antenna is more sharp, the side lobe level is reduced, and the directional radiation performance is comprehensively enhanced.

[0043] The above embodiments of the present application are described in detail in combination with the drawings, and those of ordinary skill in the art can make various changes to the present application according to the above description. Thus, certain details in the embodiments should not constitute a limitation on the present application, and the scope of protection of the present application shall be defined by the appended claims.

Claims

1. A metasurface antenna for suppressing higher-order modes and enhancing directional radiation, characterized in that, include: Base plate; A dielectric substrate is disposed on the upper surface of the base plate; The main array, consisting of multiple metal patches arranged at periodic intervals, is disposed on the upper surface of the dielectric substrate; At least one auxiliary patch is disposed on the upper surface of the dielectric substrate and located on the periphery of the main array, and a resistive element is loaded on the auxiliary patch; A power feeding structure, penetrating the base plate and the dielectric substrate, is electrically connected to the main array and is used to excite the main array; The auxiliary patch interacts with the main array via electromagnetic coupling, forming a buddy system for suppressing higher-order mode radiation of the main array and enhancing its directional radiation performance.

2. The metasurface antenna for suppressing higher-order modes and enhancing directional radiation according to claim 1, characterized in that: The coupling distance between the auxiliary patch and the main array is adjustable, and this coupling distance can be adjusted to optimize the suppression bandwidth and degree of higher-order modes.

3. The metasurface antenna for suppressing higher-order modes and enhancing directional radiation according to claim 1, characterized in that: The resistance of the resistive element loaded on the auxiliary patch is adjustable, and the degree of energy dissipation in higher-order modes can be controlled by adjusting the resistance value.

4. The metasurface antenna for suppressing higher-order modes and enhancing directional radiation according to claim 1, characterized in that: The resistive element loaded on the auxiliary patch is connected to the base plate through a via through the dielectric substrate, forming a current dissipation path.

5. The metasurface antenna for suppressing higher-order modes and enhancing directional radiation according to claim 1, characterized in that: The design of the buddy system is based on supersymmetric transformation, which couples the auxiliary patch with the higher-order modes of the main array at the same resonant frequency and converts the energy of the higher-order modes into non-radiative heat dissipation, while maintaining mode orthogonality with the fundamental mode.

6. The metasurface antenna for suppressing higher-order modes and enhancing directional radiation according to claim 1, characterized in that: The metal patches are arranged in a 3x3 square, and there are multiple auxiliary patches, which are respectively arranged around the main array formed by the 3x3 square arrangement of the metal patches.

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