CN110518344B

CN110518344B - Self-balancing wide-bandwidth wave beam magnetic dipole antenna

Info

Publication number: CN110518344B
Application number: CN201910773241.2A
Authority: CN
Inventors: 吕文俊; 吴汉; 沈成; 吴志芳; 赵志宾; 王见远; 李司杰; 李小慧; 朱洪波
Original assignee: Nanjing University of Posts and Telecommunications
Current assignee: Nanjing University of Posts and Telecommunications
Priority date: 2019-08-21
Filing date: 2019-08-21
Publication date: 2020-08-11
Anticipated expiration: 2039-08-21
Also published as: CN110518344A

Abstract

The invention discloses a self-balancing broadband wide-beam magnetic dipole antenna, which belongs to the technical field of Internet of things and microwave and comprises an upper surface and a lower surface of a semicircular patch, wherein the upper surface is positioned right above the lower surface, the side edges of the upper surface and the lower surface are vertical short circuit walls, and a semicircular magnetic dipole structure is formed after matching. The antenna is composed of a semicircular magnetic dipole, two rectangular grooves are formed in the upper surface of the magnetic dipole to adjust a high-order mode so as to expand bandwidth, self-balancing feeding is achieved through the area difference of the upper surface and the lower surface of the magnetic dipole, wide beam bandwidth can be achieved without a large-area metal reflecting plate, and the performance of the antenna is controlled by the rotation angle of the rectangular grooves around the central axis of the semicircular magnetic dipole, the length of the rectangular grooves and the width of the rectangular grooves. The invention has the characteristics of small volume, high gain, low section and simple structure, and has wide application prospect in various wireless sensing and radio frequency identification systems of the Internet of things.

Description

Self-balancing wide-bandwidth wave beam magnetic dipole antenna

Technical Field

The invention belongs to the technical field of Internet of things and microwaves, and particularly relates to a self-balancing type wide-bandwidth beam magnetic dipole antenna.

Background

With the rapid development of wireless technology, wide-beam antennas have been widely used in modern fields such as communication, broadcasting, navigation, and the like. In the past decades, various wide beam technologies have been proposed, and the design methods of wide beam antennas can be basically classified into five different types according to the basic operation principle of the wide beam antennas.

The first is a reflective shaping technique; the second is a rotational configuration technique; the third is complementary dipole antenna technology; the fourth is a material-based technique; the last is parasitic element technology.

These antennas are all sized in cross-section above 0.1 wavelength (typical size is 0.25 wavelength), are relatively complex in structure and lack common design criteria. Therefore, the development of a low-profile planar wide-beam antenna with a simple structure belongs to one of the challenging problems in the antenna field.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to provide a self-balancing wide-bandwidth wave beam magnetic dipole antenna, which realizes double resonance to expand bandwidth and realizes self-balancing feed by utilizing the area difference of the upper surface and the lower surface of a magnetic dipole.

The technical scheme is as follows: in order to achieve the purpose, the invention provides the following technical scheme:

a self-balancing wide-bandwidth wave beam magnetic dipole antenna comprises an upper surface and a lower surface of a semicircular patch, wherein the upper surface is positioned right above the lower surface, the side edges of the upper surface and the lower surface are vertical short circuit walls, and a semicircular magnetic dipole structure is formed after matching.

Furthermore, a rectangular groove is formed in the upper surface.

Furthermore, the rectangular grooves are symmetrically arranged on two sides of a central axis of the semicircular magnetic dipole structure.

Further, the semicircular magnetic dipole structure is a non-closed structure.

Further, the radius of the lower surface is larger than one fifth wavelength to one third wavelength of the radius of the upper surface.

Further, the main beam width of the self-balanced wide bandwidth beam magnetic dipole antenna ranges from 100 degrees to 110 degrees, and is controlled by the radius difference between the upper surface and the lower surface.

Further, a feed structure is disposed on the upper surface.

Furthermore, the feed structure is a coaxial line, and comprises a coaxial line inner conductor and a coaxial line outer conductor.

Further, a medium with any dielectric constant is filled between the upper surface and the lower surface.

Has the advantages that: compared with the prior art, the self-balancing wide-bandwidth wave beam magnetic dipole antenna has the advantages that the semicircular magnetic dipole structure is used, the two rectangular grooves which are symmetrical by the central axis of the magnetic dipole are formed in the upper surface of the semicircular magnetic dipole structure, double resonance is realized to expand the bandwidth, self-balancing feeding is realized by utilizing the area difference of the upper surface and the lower surface of the magnetic dipole, the wide wave beam width can be realized without a large-area metal reflecting plate, the manufacturing process is simple, and the cost is low.

Drawings

FIG. 1 is a schematic diagram of the front structure and reference coordinates of an antenna;

FIG. 2 is a schematic three-dimensional view of an antenna and a schematic reference coordinate;

FIG. 3 is a schematic representation of antenna reflection coefficients calculated using HFSS software;

FIG. 4 is a ZX plane pattern plotted using HFSS software;

FIG. 5 is a ZY plane pattern using HFSS software;

FIG. 6 is a graph of antenna gain calculated using HFSS software;

reference numerals: 1-upper surface, 2-rectangular groove, 3-central axis, 4-inner conductor, 5-outer conductor, 6-lower surface and 7-short circuit wall.

Detailed Description

For a better understanding of the contents of the present patent application, the technical solutions of the present invention will be further described below with reference to the accompanying drawings and specific examples.

As shown in fig. 1-2, the self-balancing broadband wide-beam magnetic dipole antenna comprises a semicircular magnetic dipole structure and two rectangular grooves 2 which are symmetrical by using a central axis 3 of a magnetic dipole, wherein the semicircular magnetic dipole structure is a non-closed structure and is composed of two different semicircular patches and a vertical short-circuit wall 7 which is connected with straight edges of the two semicircular patches, the two different semicircular patches are respectively an upper surface 1 and a lower surface 6 of the semicircular magnetic dipole structure, and the upper surface 1 is positioned right above the lower surface 6. Two rectangular grooves 2 are arranged on the upper surface 1 of the semicircular magnetic dipole structure.

The radius of the lower surface 6 of the semicircular magnetic dipole structure is larger than the radius of the upper surface 1 of the semicircular magnetic dipole structure by one fifth wavelength to one third wavelength, the width range of the main beam is 100 degrees to 110 degrees, and the radius difference of the upper surface 1 and the lower surface 6 is controlled.

The self-balancing broadband wide-beam magnetic dipole antenna has the advantages that the relative bandwidth is more than 30%, the main polarized beam width is more than 100 degrees, the size is small, the gain is high, the structure is simple, the section size is low, and the manufacturing and the implementation are convenient under the condition that a grounding plate is not needed.

And a feed structure is arranged on the non-closed fan-shaped planar magnetic dipole. The feed structure is a coaxial line and is formed by a coaxial line inner conductor 4 and an outer conductor 5.

The number and the positions of the rectangular slots 2 are determined according to the surface magnetic current distribution function of the high-order resonance mode. The length and width of the rectangular groove 2 can be changed. The angle between the rectangular groove 2 and the central axis 3 of the semicircular magnetic dipole can be changed. The radius of the upper surface 1 and the lower surface 6 of the semicircular magnetic dipole structure can be changed. The upper surface 1 and the lower surface 6 of the two semicircular patches of the semicircular magnetic dipole structure can be filled with any dielectric constant medium.

Example 1

In the embodiment, an air medium is adopted, the distance between the upper surface 1 and the lower surface 6 of the semicircular magnetic dipole structure is 6mm, the radiuses of the upper surface 1 and the lower surface 6 of the semicircular magnetic dipole structure are 36mm and 61mm respectively, the length and the width of the rectangular groove 2 are 16mm and 5mm respectively, an included angle between the rectangular groove 2 and the central axis 3 of the semicircular magnetic dipole structure is 35 degrees, a feed point is located on the central axis 3 of the semicircular magnetic dipole structure and 31mm away from the center of a circle, and various characteristics of the antenna are obtained through simulation calculation by HFSS software.

Fig. 3 is a graph of the reflection coefficient characteristics of the antenna calculated using HFSS software, the impedance bandwidth of the antenna covering the 2.44GHz-3.37GHz band, the center frequency being 2.9GHz, and the relative bandwidth being about 32%.

FIGS. 4 and 5 are calculated radiation patterns of the antenna in the ZX and ZY planes using HFSS software, where FIG. 4 is the pattern of the ZX plane at 2.45GHz operating frequency for the antenna; fig. 5 is a ZY-surface pattern of the antenna at 2.45GHz operating frequency. As can be seen from fig. 4 and 5, the half-power beam angle of the antenna can reach over 100 °.

Fig. 6 shows the gain characteristic of the antenna in the operating frequency band calculated by using HFSS software, and the gain can reach 7.03dBi in the maximum radiation direction of the antenna resonant frequency.

In summary, in the design method of the self-balancing wide bandwidth beam magnetic dipole antenna, two rectangular grooves 2 are formed in the upper surface of the antenna to adjust a high-order mode to realize bandwidth expansion, self-balancing feeding is realized by utilizing the area difference of the upper surface and the lower surface of the antenna, a wide beam bandwidth can be obtained without a large-area metal reflector, and the antenna has the advantages of small size, high gain, simple structure, low section size and convenience in manufacturing and implementation.

Claims

1. A self-balancing wide bandwidth wave beam magnetic dipole antenna is characterized in that: the magnetic dipole patch comprises an upper surface (1) and a lower surface (6) of a semicircular patch, wherein the upper surface (1) is positioned right above the lower surface (6), the side edges of the upper surface (1) and the lower surface (6) are vertical short circuit walls (7), and a semicircular magnetic dipole structure is formed after matching; a rectangular groove (2) is arranged on the upper surface (1); the rectangular grooves (2) are symmetrically arranged on two sides of a central axis (3) on the semicircular magnetic dipole structure; the radius of the lower surface (6) is larger than one fifth wavelength to one third wavelength of the radius of the upper surface (1).

2. The self-balanced wide bandwidth beam magnetic dipole antenna of claim 1, wherein: the semicircular magnetic dipole structure is a non-closed structure.

3. The self-balanced wide bandwidth beam magnetic dipole antenna of claim 1, wherein: the main beam width range of the self-balanced broadband wide-beam magnetic dipole antenna is 100-110 degrees.

4. The self-balanced wide bandwidth beam magnetic dipole antenna of claim 1, wherein: and a feed structure is arranged on the upper surface (1).

5. The self-balanced wide bandwidth beam magnetic dipole antenna of claim 4, wherein: the feed structure is a coaxial line and comprises a coaxial line inner conductor (4) and a coaxial line outer conductor (5).

6. The self-balanced wide bandwidth beam magnetic dipole antenna of claim 1, wherein: and a medium with any dielectric constant is filled between the upper surface (1) and the lower surface (6).