阅读说明：本技术 一种基于多模谐振的低剖面宽带贴片天线 (Low-profile broadband patch antenna based on multimode resonance ) 是由 徐溯 张际 刁杨华 刘元莹 陈志� 陈董秀 侯超 姚鹏 张懿 胡航 陈永明 于 2021-09-09 设计创作，主要内容包括：本发明涉及微波与天线技术领域,尤其涉及一种基于多模谐振的低剖面宽带贴片天线,包括从上到下依次设置的矩形贴片、介质基板和金属地面,矩形贴片的辐射边加载第一短路壁,矩形贴片的非辐射边加载相对的第二短路壁和第三短路壁,矩形贴片的下方设置有短路销钉组成的阵列,短路销钉贯穿介质基板。本发明低剖面,但中心带宽可以达到21.7％的,通过加载短路壁使得天线的辐射方向图有所改善,E面旁瓣降低,有效减小H面交叉极化。(The invention relates to the technical field of microwaves and antennas, in particular to a multimode resonance-based low-profile broadband patch antenna which comprises a rectangular patch, a dielectric substrate and a metal ground, wherein the rectangular patch, the dielectric substrate and the metal ground are sequentially arranged from top to bottom, a first short-circuit wall is loaded on a radiation side of the rectangular patch, a second short-circuit wall and a third short-circuit wall which are opposite to each other are loaded on a non-radiation side of the rectangular patch, an array formed by short-circuit pins is arranged below the rectangular patch, and the short-circuit pins penetrate through the dielectric substrate. The invention has low profile, but the central bandwidth can reach 21.7%, the radiation pattern of the antenna is improved by loading the short-circuit wall, the side lobe of the E surface is reduced, and the cross polarization of the H surface is effectively reduced.)

1. A low-profile broadband patch antenna based on multimode resonance is characterized in that: the antenna comprises a rectangular patch (1), a dielectric substrate (2) and a metal ground (3), wherein the rectangular patch (1), the dielectric substrate (2) and the metal ground (3) are sequentially arranged from top to bottom, a first short-circuit wall (11) is loaded on a radiation edge of the rectangular patch (1), a second short-circuit wall (12) and a third short-circuit wall (13) which are opposite to each other are loaded on a non-radiation edge of the rectangular patch (1), an array formed by short-circuit pins (4) is arranged below the rectangular patch (1), and the short-circuit pins (4) penetrate through the dielectric substrate (2).

2. A multimode resonance based low profile broadband patch antenna according to claim 1, wherein: the rectangular patch (1) is provided with a strip gap (14), and the strip gap (14) is parallel to an array formed by the short circuit pins (4).

3. A multimode-resonance-based low-profile broadband patch antenna according to claim 1 or 2, wherein: the strip-shaped gap (14) is arranged at the TM_3/2，0At the zero-current position of the mode, the array of short-circuit pins (4) is opened at TM_3/2，0A mode electric field node.

4. Root of herbaceous plantA low-profile broadband patch antenna based on multimode resonance as claimed in claim 3, wherein: a single shorting Pin (4) is spaced from the first shorting wall 11 in the x-direction at a distance Pin from the center plane of the rectangular patch (1)_xComprises the following steps:

Pin_x＝0.75P_x

wherein, P_xIs the width of the rectangular patch (1).

5. A multimode resonance based low profile broadband patch antenna according to claim 3, wherein: the value range of the width Slotx of the strip-shaped gap (14) is 16.7-17.7 mm, the value range of the length Sloty of the strip-shaped gap (14) is 40-50 mm, and the value range of the Slotw of the left long side of the strip-shaped gap (14) from the left long side of the rectangular patch (1) is 2-4 mm.

6. A multimode-resonance-based low-profile broadband patch antenna according to claim 1 or 2, wherein: the thickness of the low-profile broadband patch antenna based on multimode resonance is 0.03 lambda₀，λ₀Is the center frequency free space wavelength of the antenna working frequency band.

7. A multimode-resonance-based low-profile broadband patch antenna according to claim 1 or 2, wherein: the surface area of the rectangular patch (1) is smaller than that of the metal ground (3).

Technical Field

The invention relates to the technical field of microwaves and antennas, in particular to a low-profile broadband patch antenna based on multimode resonance.

Background

Microstrip patch antennas are the most basic, most common form of microstrip antennas. The microstrip patch antenna has a simple structure and is composed of a conductor grounding plate at the bottom layer, a medium substrate at the middle layer and a conductor patch at the upper layer, and the thickness of the medium substrate is smaller than the wavelength, so that the microstrip patch antenna can be miniaturized. The low-profile planar structure of the microstrip antenna is the most remarkable characteristic, so that the microstrip antenna is easily conformal with carriers in shapes of cylindrical surfaces, curved surfaces and the like. However, the low-profile structure also causes the microstrip patch antenna to be in a leaky-wave cavity shape, the resonance characteristic is similar to that of an RLC parallel resonance circuit, the Q value is high, and therefore the impedance bandwidth of the antenna is narrow.

At present, a differential feed and an aperture coupling feed are respectively adopted in a dual-mode resonance low-profile broadband patch antenna, the working bandwidth can be effectively increased to 13% by adding a short-circuit pin, but the E-plane side lobe is sharply increased to be near 0dB due to the increase of resonant frequency of one mode.

At present, there are some methods to widen the bandwidth of the microstrip antenna:

(1) the impedance bandwidth is increased by lowering the equivalent circuit Q value using a high thickness or using a dielectric substrate with a low dielectric constant, but the surface wave leakage in such a planar antenna is increased, resulting in poor radiation efficiency;

(2) the feeding mode is improved, for example, electromagnetic coupling feeding, L-shaped probe feeding and the like are adopted, but the antenna radiation mode changes along with the frequency, and the cross polarization is higher;

(3) combining multiple coupled resonant modes with parasitic elements increases bandwidth, but its volume increases much, destroying the low profile characteristics of microstrip patch antennas.

In addition, a U-shaped groove is etched on the radiating patch, an additional resonance mode is introduced near a main resonance point to expand the bandwidth, but the thickness of the antenna is larger; similar structures also include single-layer E-shaped microstrip antennas, stacked E-shaped microstrip antennas, and the like.

Multiple gaps are loaded on the rectangular patch to simultaneously excite two orthogonal modes, so that the bandwidth enhancement and the structure compactness are realized, and the frequency range is 0.01 lambda₀The impedance bandwidth of 3.8% is realized on the basis of low profile, but the antenna gain is lower and the cross polarization is as high as-5 dB due to the use of high-loss FR-4 base material and etching of multiple slots.

The short-circuit needle is loaded on the circular patch, the resonance frequency of two modes is reconstructed, 18% wide impedance bandwidth is realized in a monopole radiation mode, and 0.024 lambda can be kept₀Has the disadvantage that the radiation peak value in the working frequency band cannot be stabilized;

placing short circuit pin under equilateral triangle patch and etching V-shaped gap, exciting two modes to make antenna bandwidth reach 32%, but antenna thickness also increase to 0.09 lambda₀。

Disclosure of Invention

The invention provides a low-profile broadband patch antenna based on multimode resonance, which has the advantages of bandwidth enhancement and radiation characteristic improvement.

In order to achieve the purpose of the invention, the low-profile broadband patch antenna based on multimode resonance comprises a rectangular patch, a dielectric substrate and a metal ground which are sequentially arranged from top to bottom, wherein a first short-circuit wall is loaded on the radiation side of the rectangular patch, a second short-circuit wall and a third short-circuit wall which are opposite to each other are loaded on the non-radiation side of the rectangular patch, an array formed by short-circuit pins is arranged below the rectangular patch, and the short-circuit pins penetrate through the dielectric substrate.

As an optimized scheme of the invention, the rectangular patch is provided with strip-shaped gaps which are parallel to an array formed by the short circuit pins.

As an optimized proposal of the invention, the strip-shaped seamThe gap is arranged at TM_3/2，0At the zero current position of the mode, the array of shorting pins is opened at the TM_3/2，0A mode electric field node.

As an optimization of the invention, a single shorting Pin is at a distance Pin from the first shorting wall 11 in the x-direction at the center plane of the rectangular patch_xComprises the following steps:

Pin_x＝0.75P_x

wherein, P_xThe width of a rectangular patch.

As an optimization scheme of the invention, the value range of the width Slotx of the strip-shaped gap is 16.7-17.7 mm, the value range of the length Sloty of the strip-shaped gap is 40-50 mm, and the value range of the Slotw of the left long side of the strip-shaped gap from the left long side of the rectangular patch is 2-4 mm.

As an optimized scheme of the invention, the thickness of the low-profile broadband patch antenna based on multimode resonance is 0.03 lambda₀，λ₀Is the center frequency free space wavelength of the antenna working frequency band.

As an optimized scheme of the invention, the surface area of the rectangular patch is smaller than that of the metal ground.

The invention has the positive effects that: the invention firstly combines the TM of the patch antenna_1/2,0、TM_3/2,0And TM_RSMode combination to enhance the impedance bandwidth, then introducing TM_1/2,2The frequency of the four-mode resonant low-profile broadband antenna is reduced to three resonant mode frequency points, and the four-mode resonant low-profile broadband antenna is designed and has the thickness of only 0.03 lambda₀However, the central bandwidth can reach 21.7%, the H-plane cross polarization is greater than 20dB on the whole working frequency band, and the gain is about 8.5 dB.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

FIG. 1 is an overall block diagram of the present invention;

FIG. 2 is a top view of the present invention;

FIG. 3 shows the resonance frequency f_1/2,0，f_3/2,0And f_RSSchematic diagram of variation with Sloty;

FIG. 4 shows the resonance frequency f_1/2,0，f_3/2,0And f_RSSchematic diagram of variation with Slotx;

FIG. 5 shows the resonance frequency f_1/2,0，f_3/2,0And f_RSSchematic diagram of variation with Slotw;

FIG. 6 is a | S of simulation and measurement₁₁| and gain plots;

FIG. 7 is an E-plane 2.7GHz simulation and measurement normalized far-field radiation pattern;

FIG. 8 is an H-plane 2.7GHz simulation and measurement normalized far-field radiation pattern;

FIG. 9 is an E-plane 2.9GHz simulation and measurement normalized far-field radiation pattern;

FIG. 10 is an H-plane 2.9GHz simulation and measurement normalized far-field radiation pattern;

FIG. 11 is an E-plane 3.1GHz simulation and measurement normalized far-field radiation pattern;

FIG. 12 is an H-plane 3.1GHz simulation and measurement normalized far-field radiation pattern;

FIG. 13 is an E-plane 3.3GHz simulation and measurement normalized far-field radiation pattern;

figure 14 is an H-plane 3.3GHz simulation and measurement normalized far-field radiation pattern.

Wherein: 1. rectangular patch, 2, dielectric substrate, 3, metal ground, 11, first short-circuit wall, 12, second short-circuit wall, 13, third short-circuit wall, 4, short-circuit pin, 14, strip-shaped gap.

Detailed Description

The implementation of the invention is described in further detail below with reference to the attached drawing figures:

as shown in fig. 1-2, the invention discloses a multimode resonance-based low-profile broadband patch antenna, which comprises a rectangular patch 1, a dielectric substrate 2 and a metal ground 3 which are sequentially arranged from top to bottom, wherein a first short-circuit wall 11 is loaded on a radiation edge of the rectangular patch 1, a second short-circuit wall 12 and a third short-circuit wall 13 which are opposite to each other are loaded on a non-radiation edge of the rectangular patch 1, an array consisting of short-circuit pins 4 is arranged below the rectangular patch 1, and the short-circuit pins 4 penetrate through the dielectric substrate 2.

The loading of the first short-circuit wall 11 can inhibit an even-order mode and reduce the high side lobe of the E surface; loading the second shorting wall 12 can reduce the high cross polarization of the H-plane radiation pattern. The short-circuit wall can greatly improve the radiation performance of the far area of the antenna.

The rectangular patch 1 is provided with strip-shaped slits 14, and the strip-shaped slits 14 are parallel to the array formed by the short circuit pins 4. The strip-shaped gap 14 is arranged at the TM_3/2，0The array of shorting pins 4 opens at the TM at the zero current position of the mode_3/2，0A mode electric field node.

TM in patch_3/2,0Four short circuit pins are inserted near the node line of the mode electric field to keep f_3/2,0Constant, increasing f_1/2,0And f_1/2,2(ii) a Finally at TM_3/2,0Strip-shaped slits 14 are etched near the zero current line of the mode, exciting the slit radiation mode TM_RSImplementation is based on TM_1/2,0、TM_3/2,0And TM_RSThe three-mode resonant low-profile broadband antenna of (1).

The invention firstly combines the TM of the patch antenna_1/2,0、TM_3/2,0And TM_RSThe resonant frequencies of the modes are redistributed to positions close to each other to increase the bandwidth, and an array of four shorting pins 4 is loaded under the rectangular patch 1, and f_1/2,0Lifting to about 2.68GHz while keeping f_3/2,0In the vicinity of 2.83GHz, when f_1/2,2Is also raised to 3.75GHz, far from f_3/2,0. TM on the rectangular Patch 1_3/2,0A gap is cut near the zero current line of the mode to excite the TMRS mode and to the TM_1/2,0And TM_3/2,0The influence of the mode is controllable, in which case TM_RSMode operation at 3.07GHz, close to f_1/2,0And f_3/2,0. By these measures, the bandwidth and radiation performance of the antenna are improved under simultaneous radiation of three resonant modes.

The single shorting Pin is at a distance Pin from the first shorting wall 11 in the x-direction at the center plane of the rectangular patch_xComprises the following steps:

Pin_x＝0.75P_x

wherein, P_xThe width of a rectangular patch. In Pin_x/P_xAfter reaching about 0.75, because the shorting pin 4 is properly placed in the TM_3/2,0The minimum f can be obtained around the nodal line of the electric field of the mode_3/2,0/f_1/2,0。

The width Slotx of the strip-shaped gap 14 ranges from 16.7mm to 17.7mm, the length Sloty of the strip-shaped gap 14 ranges from 40mm to 50mm, and the distance from the left long side of the strip-shaped gap 14 to the left long side of the rectangular patch 1 ranges from 2mm to 4 mm.

To further broaden the impedance bandwidth of the antenna, at TM_3/2,0Etching a linear slot in the radiating patch near the zero current line of the mode to excite the TM of the patch antenna_RSMold and move it closer to TM_1/2,0And TM_3/2,0And (5) molding. By appropriately modifying the strip-shaped slot 14 length (Sloty), TM can be combined_3/2,0And TM_RSModes to extend the bandwidth. Three-mode resonant frequency f_1/2,0，f_3/2,0And f_RSAs Sloty varies, see FIG. 3, from which it can be seen that f increases from 40mm to 50mm_RSFrom 3.5GHz down sharply to 3.1GHz, but f1/2,0 and f3/2,0 remain substantially unchanged, so Sloty is chosen to be 50mm for the widest bandwidth. Further adjusting the slot position (Slotx) and width (Slotw) to analyze the impedance matching problem, fig. 4 and 5 show that the increase of Slotx from 16.7mm to 17.7mm and the increase of Slotw from 2mm to 4mm, especially when the Slotx is 17.2mm and the Slotw is 3mm, a wider bandwidth and good impedance matching can be achieved.

FIG. 6 shows | S for simulation and measurement₁₁L and gain. It can be seen that there are four resonance points in the operating band within 2.5 to 3.4GHz, which is consistent with the four resonance modes simulated, i.e., TM_1/2,0(2.68GHz)，TM_3/2,0(2.9GHz)、TM_RS(3.1GHz) and TM_1/2,2(3.3 GHz). The proposed measured operating bandwidth extends further from 18% (2.64GHz-3.17GHz) to 21.7% (2.67-3.32GHz) of a three-mode antenna due to the combination of the four resonant modes.

As shown in fig. 7-14, normalized far-field radiation patterns for simulation and measurement of a multimode resonance-based low-profile broadband patch antenna at four resonance poles of 2.7GHz, 2.9GHz, 3.1GHz, and 3.3GHz, respectively, correspond to four resonance modes. In addition, a stable radiation pattern is obtained in the working waveband, the side lobe of an E-plane radiation pattern of the antenna is low due to the loading of the first short-circuit wall 11 and the second short-circuit wall 12, meanwhile, the overall H-plane cross polarization is low and is reduced to be lower than-20 dB, and the measured peak gain in a frequency band is about 9 dBi.

The above-mentioned embodiments only express the embodiments of the present invention, and the description thereof is more specific and detailed, and therefore, the present invention should not be construed as limiting the scope of the present invention. It should be noted that several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.