Multi-mode coupling broadband filtering antenna based on substrate integrated waveguide

Abstract

The invention relates to a multi-mode coupling broadband filtering antenna based on a substrate integrated waveguide, and belongs to the field of wireless energy transmission. The antenna comprises a bottom-layer metal floor, a middle-layer dielectric substrate, an upper-layer metal floor and four groups of cavity columns, the bottom-layer metal floor is arranged on the lower surface of the middle-layer dielectric substrate, and a pair of U-shaped grooves are formed in the center of the bottom-layer metal floor; a feed hole is formed in the U-shaped groove; the upper-layer metal floor is arranged on the upper surface of the middle-layer dielectric substrate, and a square groove is etched in the upper-layer metal floor; a square microstrip patch is arranged in the square groove; the four groups of cavity columns penetrate through the bottom layer metal floor, the middle layer dielectric substrate and the upper layer metal floor to define a square SIW cavity.

Description

Technical Field

[0001] The invention belongs to the field of wireless energy transmission and relates to a multi-mode coupled broadband filtering antenna based on a substrate integrated waveguide. Background Art

[0002] With the rapid development of wireless communication technology, the functions and performance of wireless devices are constantly improving, and the requirements for miniaturization, integration, and wide bandwidth of RF front-end circuits are becoming increasingly higher. As two important components of RF front-end circuits, the size, performance, and structure of filters and antennas have a significant impact on the performance and volume of the entire system.

[0003] In the traditional antenna design process, filters need to be connected to select the frequency, which makes the RF front-end components too large and is not conducive to the miniaturization of the system. The application of multi-layer structures limits the integration with planar circuits and increases manufacturing costs. Although traditional filter antennas have good filtering response, their bandwidth is relatively narrow and it is difficult to meet the needs of modern wireless communications.

[0004] In the prior art, in order to achieve wide bandwidth and good filtering performance, a multilayer structure is usually used to design a filtering antenna. Although this structure can achieve good performance, it increases the manufacturing cost and is not conducive to integration with planar circuits. Although a certain wide bandwidth can be obtained by designing a filtering antenna by means of slotting, the filtering performance is relatively poor. The structure of the filtering antenna is complex and is not conducive to processing and manufacturing. It is difficult for the filtering antenna to simultaneously meet the requirements of wide bandwidth, good filtering performance and radiation characteristics.

[0005] It is necessary to design a filtering antenna which has a simple structure, is easy to process and manufacture, is easy to integrate with a planar circuit, has a wide bandwidth, and has good filtering performance and excellent radiation characteristics. Summary of the invention

[0006] In view of this, the purpose of the present invention is to provide a multi-mode coupled broadband filtering antenna based on substrate integrated waveguide to solve the problems of miniaturization, integration, wide bandwidth and so on of RF front-end circuit. The antenna has three radiation zero points in the working frequency band and has good frequency selectivity. At the same time, the antenna has wide bandwidth and good filtering performance. Through analysis, design and optimization, a simple single-layer antenna structure is obtained, which is easy to process and manufacture.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A multi-mode coupled broadband filtering antenna based on substrate integrated waveguide comprises a bottom metal floor, a middle dielectric substrate, an upper metal floor and four groups of cavity columns; the bottom metal floor is arranged on the lower surface of the middle dielectric substrate, a pair of U-shaped grooves are arranged at the center of the bottom metal bottom plate; a feeding hole is arranged in the U-shaped groove; the upper metal floor is arranged on the upper surface of the middle dielectric substrate, a square groove is etched on the upper metal floor; a square microstrip patch is arranged in the square groove; the four groups of cavity columns penetrate the bottom metal floor, the middle dielectric substrate and the upper metal floor to form a square SIW cavity.

[0009] Furthermore, the pair of U-shaped grooves are symmetrically etched at the center of the bottom metal floor, the square groove is arranged in the middle of the upper metal floor, and the square microstrip patch is arranged in the center of the square groove.

[0010] Furthermore, the middle-layer dielectric substrate is square, and the four groups of cavity columns are evenly distributed along the four sides of the middle-layer dielectric substrate.

[0011] Furthermore, the relative dielectric constant of the middle-layer dielectric substrate is 2.55, and the loss tangent is 0.0014.

[0012] Furthermore, the diameter of the cavity column is 1 mm, the distance between the cavity columns is 2 mm, and the side length of the enclosed square SIW cavity is 44 mm.

[0013] Furthermore, the side length of the square groove is 22.9 mm and the width is 3.35 mm, and the side length of the square microstrip patch is 16.2 mm.

[0014] Furthermore, the two short sides of the U-shaped groove are 8.7 mm, the short side groove width is 0.44 mm, the long side is 10.12 mm, the long side groove width is 0.4 mm, and the shortest distance from one side of the U-shaped groove away from the cavity to the four groups of cavity column edges is 11.9 mm.

[0015] The beneficial effects of the present invention are:

[0016] (1) Use SIW cavity technology to complete the design of a resonant mode and provide a wide bandwidth. Etch a square groove on the upper surface of the SIW cavity and place a square patch in the center of the square groove. Etch a symmetrical U-shaped groove structure on the lower surface of the antenna. The TE of the cavity 110 The mode creates a low-frequency radiation null. The top square patch and the cavity TE 210 The mutual coupling of modes introduces a new resonant mode for the antenna and generates a high-frequency radiation zero point in the upper stopband, thus improving the filtering effect at the upper edge of the passband. 110Mode coupling introduces a new radiation zero point for the lower edge of the passband, further improving the low-frequency filtering effect of the antenna. At the same time, the three radiation zero points can be independently controlled by specific parameters. The three radiation zero points effectively suppress interference signals outside the passband, improving the system's anti-interference ability and communication quality. The introduced square patch and U-shaped slot realize multipath coupling to expand the antenna bandwidth and improve the performance of the antenna.

[0017] (2) The antenna operates at a center frequency of 4.73 GHz, an impedance bandwidth of 15.8% (4.38-5.13 GHz), and can achieve a gain of 6.1 dBi.

[0018] (3) While achieving high performance, the antenna also ensures stable side radiation characteristics. The cross-polarization levels of the E-plane and H-plane at 4.72 GHz are both greater than 25 dB, and the cross-sectional height of the antenna is 0.05λ0. The antenna has superior performance, small size, simple structure, good frequency selectivity and other characteristics, and has certain use value.

[0019] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0021] Figure 1 This is a schematic diagram of the structure of the multi-mode coupled broadband filtering antenna based on substrate integrated waveguide according to the present invention;

[0022] Figure 2 This is a schematic diagram of the dimensions of the multi-mode coupled broadband filtering antenna based on substrate integrated waveguide according to the present invention;

[0023] Figure 3 The S11 parameters and achievable gain of the multi-mode coupled broadband filtering antenna based on substrate integrated waveguide of the present invention;

[0024] Figure 4 The radiation pattern of the multi-mode coupled broadband filtering antenna based on substrate integrated waveguide of the present invention, wherein (a) is the normalized radiation pattern of the E plane of the antenna at 4.72 GHz, and (b) is the normalized radiation pattern of the H plane of the antenna at 4.72 GHz;

[0025] Reference numerals: upper metal floor 1 , middle dielectric substrate 2 , bottom metal floor 3 , cavity column 4 , feeding column 5 , square slot 6 , square patch 7 , U-shaped slot 8 . DETAILED DESCRIPTION

[0026] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0027] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0028] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0029] See also Figure 1The present invention provides a multi-mode coupled broadband filtering antenna based on substrate integrated waveguide, the antenna comprising an upper metal floor 1, a middle dielectric substrate 2, a bottom metal floor 3, a cavity column 4, a feed column 5, a square slot 6, a square patch 7 and a U-shaped slot 8. The upper metal floor 1 is arranged on the upper surface of the middle dielectric substrate 2, and the bottom metal floor 3 is arranged on the lower surface. Four groups of cavity columns 4 are evenly arranged along the four sides of the middle dielectric substrate 2, with 22 in each group, penetrating the bottom metal floor 3, the middle dielectric substrate 2 and the upper metal floor 1 to form a square SIW cavity. Feed columns 5 are arranged in the SIW cavity, penetrating the bottom metal floor 3, the middle dielectric substrate 2 and the upper metal floor 1 respectively. A square hollow is etched on the upper metal floor 1, and a pair of square patches 7 are arranged at the center of the exposed upper surface of the middle dielectric substrate 2, and a square slot 6 is formed at the same time.

[0030] The two metal floors are the same size as the dielectric substrate, with a side length of 46mm. The shortest distance from the feeding position to the edge of the SIW cavity is 14.6mm. The diameter of the feeding column is 1mm, and the shortest distance from the edge of the SIW cavity is 4.3mm. The two short sides of the U-shaped groove are 8.7mm, the short side groove width is 0.44mm, the long side is 10.12mm, the long side groove width is 0.4mm, and the shortest distance from the side of the U-shaped groove away from the cavity to the four groups of cavity column edges is 11.9mm.

[0031] The distance between the cavity columns is 2mm and the diameter is 1mm. The side length of the square patch is 16.2mm. The square patch is located in the center of the upper metal floor. The copper thickness of the upper metal floor, the upper metal floor and the patch is 0.017mm, and the thickness of the dielectric substrate is 3.175mm.

[0032] The material of the dielectric substrate is Arlon AD255C, which has a relative dielectric constant of 2.55 and a loss tangent of 0.0014.

[0033] The high-frequency electromagnetic simulation software HFSS2022 is used to simulate the substrate integrated waveguide-based multi-mode coupled broadband filtering antenna. The parameters after simulation optimization are shown in Table 1, in units of mm.

[0034] Table 1

[0035] W <![CDATA[W1]]> <![CDATA[W2]]> <![CDATA[W3]]> 46 44 22.8 16.2 <![CDATA[W4]]> <![CDATA[W5]]> <![CDATA[L1]]> <![CDATA[L2]]> 0.4 0.44 4.3 11 <![CDATA[L3]]> <![CDATA[L4]]> <![CDATA[d1]]> <![CDATA[d2]]> 8.7 11.9 0.96 2 <![CDATA[d3]]> p H t 1 2 3.175 0.017

[0036] Reference Figure 2, W is the side length of the dielectric substrate, the upper metal floor and the bottom metal floor, W1 is the side length of the SIW cavity, W2 is the side length of the square slot, W3 is the side length of the square patch, W4 is the width of the long side of the U-shaped slot, and W5 is the width of the short side of the U-shaped slot; L1 is the closest distance between the feed column and the SIW cavity, L2 and L3 are the lengths of the short and long sides of the U-shaped slot respectively, L4 is the closest distance between the long side of the U-shaped slot and the SIW cavity, d1-d3 are the diameters of the penetration between the feed column and the upper metal floor, the cavity and the feed column and the bottom metal floor respectively, p is the spacing between the cavity columns, H is the thickness of the middle dielectric substrate, t is the copper thickness of the upper metal floor, the upper metal floor and the patch.

[0037] Figure 3 The S11 parameter obtained by the simulation of the present invention can realize a curve diagram of gain changing with frequency. Figure 3 As shown. The measured -10dB fractional impedance bandwidth is 15.8% (from 4.38GHz to 5.13GHz), with three obvious in-band resonances. Referring to the measured achieved gain curve, it shows good filtering capability, with three radiation zeros in the stopband, all of which are controllable. The peak achieved gain is about 6.1dBi. Figure 4 In the figure, (a) and (b) respectively describe the normalized radiation patterns of the E-plane and H-plane at the resonant frequency of 4.72 GHz. Since the cross-polarization of the E-plane is too small, there is only the main polarization curve. The results show that the developed filtering antenna has stable broadside radiation characteristics. In addition, the cross-polarization of the E-plane and the H-plane are both greater than 25 dB.

[0038] A person skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing related hardware through a program. The program can be stored in a computer-readable storage medium. When the program is executed, the steps of the method can be implemented. The storage medium, such as ROM / RAM, a disk, an optical disk, etc.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A multi-mode coupled broadband filtering antenna based on substrate integrated waveguide, characterized in that: It includes a bottom metal floor, a middle dielectric substrate, an upper metal floor and four groups of cavity columns; The bottom metal floor is arranged on the lower surface of the middle dielectric substrate, and a pair of U-shaped grooves are arranged at the center of the bottom metal bottom plate; A feeding hole is provided in the U-shaped groove; The upper metal floor is arranged on the upper surface of the middle dielectric substrate, and a square groove is etched on the upper metal floor; A square microstrip patch is arranged in the square groove; The four groups of cavity columns penetrate the bottom metal floor, the middle dielectric substrate and the upper metal floor to form a square SIW cavity.

2. The multi-mode coupled broadband filtering antenna based on substrate integrated waveguide according to claim 1, characterized in that: The pair of U-shaped grooves are symmetrically etched at the center of the bottom metal floor, the square groove is arranged in the middle of the upper metal floor, and the square microstrip patch is arranged in the center of the square groove.

3. The multi-mode coupled broadband filtering antenna based on substrate integrated waveguide according to claim 1, characterized in that: The middle-layer dielectric substrate is square, and the four groups of cavity columns are evenly distributed along the four sides of the middle-layer dielectric substrate.

4. The multi-mode coupled broadband filtering antenna based on substrate integrated waveguide according to claim 1, characterized in that: The relative dielectric constant of the middle-layer dielectric substrate is 2.55, and the loss tangent is 0.0014.

5. The multi-mode coupled broadband filtering antenna based on substrate integrated waveguide according to claim 1, characterized in that: The diameter of the cavity column is 1 mm, the distance between the cavity columns is 2 mm, and the side length of the square SIW cavity is 44 mm.

6. The multi-mode coupled broadband filtering antenna based on substrate integrated waveguide according to claim 1, characterized in that: The side length of the square groove is 22.9 mm and the width is 3.35 mm. The side length of the square microstrip patch is 16.2 mm.

7. The multi-mode coupled broadband filtering antenna based on substrate integrated waveguide according to claim 1, characterized in that: The two short sides of the U-shaped groove are 8.7 mm, the short side groove width is 0.44 mm, the long side is 10.12 mm, the long side groove width is 0.4 mm, and the shortest distance from one side of the U-shaped groove away from the cavity to the four groups of cavity column edges is 11.9 mm.

Images