A high-gain broadband circularly polarized microstrip antenna

Abstract

The utility model provides a high-gain broadband circularly polarized microstrip antenna, comprising a dielectric substrate, a radiation patch printed on the dielectric substrate, and a reflective ground surface printed on the back of the dielectric substrate, characterized in that the radiation patch is composed of three groups of nine patches of different sizes, and grooves of different lengths and widths are etched in the 45° direction of the center of each patch to produce circular polarization of different frequencies. The utility model uses coupling between radiation patches of different sizes to broaden the working bandwidth and improve the antenna gain, and etches grooves of different lengths and widths in the 45° direction of the center of the patch to produce a broadband circular polarization effect. The metal reflective ground surface on the back provides good directivity for the antenna. In addition, the antenna is fed by coaxial backfeeding. Since the antenna structure is relatively simple, the processing method and processing flow are greatly simplified, and it is an antenna structure with great potential suitable for satellite communications.

Description

Technical Field

[0001] The utility model relates to the technical field of antennas, in particular to a high-gain broadband circularly polarized microstrip antenna. Background Art

[0002] Circularly polarized antennas have been widely studied in the communications industry because of their ability to receive any linearly polarized beam. In recent years, with the explosive growth of communication data, the performance requirements for antennas have become increasingly higher. Microstrip circularly polarized antennas have the advantages of low profile, simple structure, stable performance, and low processing cost. They are usually used as transceiver antennas in the field of satellite communications. However, they have disadvantages such as narrow bandwidth and low gain, which are also problems that need to be solved in the design of microstrip circularly polarized antennas. Utility Model Content

[0003] In order to solve the above problems, the utility model discloses a high-gain broadband circularly polarized microstrip antenna, which uses coupling between radiation patches of different sizes to broaden the working bandwidth and improve the antenna gain, and etches grooves of different lengths and widths at a 45° direction in the center of the patch to produce a broadband circularly polarized effect. The metal reflective ground at the back provides good directivity for the antenna. In addition, the antenna is fed by coaxial backfeed. Since the antenna structure is relatively simple, the processing method and processing flow are greatly simplified, and it is an antenna structure with great potential suitable for satellite communications.

[0004] In order to achieve the above object, the technical solution of the utility model is as follows:

[0005] A high-gain broadband circularly polarized microstrip antenna comprises a dielectric substrate, a radiation patch printed on the dielectric substrate, and a reflective ground printed on the back of the dielectric substrate. The radiation patch consists of three groups of nine patches of different sizes. Grooves of different lengths and widths are etched in the 45° direction at the center of each patch to generate circular polarization of different frequencies.

[0006] Furthermore, the three groups of nine patches of different sizes are arranged in three rows and three columns, wherein the patches above, below, left and right of the patch located in the center have the same size and groove structure; the patches on the upper left, upper right, lower left and lower right of the patch located in the center have the same size and groove structure.

[0007] Furthermore, the reflective ground is made of copper.

[0008] Furthermore, the feeding mode of the high-gain broadband circularly polarized microstrip antenna adopts a coaxial back-feeding form, specifically, the coaxial probe position is connected to the copper foil on the back side of the patch located in the center, and the distance between the probe position and the lower boundary of the patch in the center is s=1.5mm.

[0009] The beneficial effects of the utility model are:

[0010] By performing electromagnetic simulation on the structure, it can be found that this structure has the following three advantages:

[0011] (a) The utility model is evolved from the microstrip antenna structure, retaining the advantages of the microstrip antenna such as low profile, easy processing and low cost.

[0012] (b) The utility model greatly broadens the working bandwidth and circular polarization bandwidth of the microstrip antenna through coupling between radiation patches of different sizes and slots on the patches.

[0013] (c) The antenna designed in the utility model maintains high gain and good directivity within the working frequency band. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of the utility model from top view;

[0015] Figure 2 It is a right view structural schematic diagram of the utility model;

[0016] Figure 3 is the reflection coefficient of the antenna simulation of the utility model

[0017] Figure 4 is the axial ratio and gain of the antenna simulation of the utility model;

[0018] Figure 5 It is the directional diagram of the antenna simulation of the utility model. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the utility model more clear, the features and performance of the utility model are described in detail below with reference to the accompanying drawings. Example

[0020] like Figure 1-2 As shown, a high-gain broadband circularly polarized microstrip antenna of the utility model comprises a dielectric substrate 1, a radiation patch 2 printed on the dielectric substrate, and a reflective ground 3 printed on the back of the dielectric substrate, wherein the radiation patch is composed of three groups of nine patches of different sizes, and grooves of different lengths and widths are etched in the 45° direction at the center of each patch to generate circular polarization of different frequencies.

[0021] In this embodiment, the three groups of nine patches of different sizes are arranged in three rows and three columns, and are represented by numbers 2-1, 2-2, 2-3, 2-4, 2-5, 2-6, 2-7, 2-8, and 2-9 respectively. The patches above, below, left, and right of the patch 2-5 located in the center, that is, patches 2-2, 2-4, 2-6, and 2-8 have the same size and groove structure; the patches on the upper left, upper right, lower left, and lower right of the patch 2-5 located in the center, that is, patches 2-1, 2-3, 2-7, and 2-9 have the same size and groove structure. In this embodiment, the patch is composed of three groups of square copper sheets with different sizes and different spacings. The patch and groove sizes of the patch 2-5 located in the center of the figure are: w1=14mm, ws1=0.6mm, ls1=15mm; the patch and groove sizes used by the patches above, below, left and right of the patch 2-5 located in the center are: w2=12.5mm, ws2=1.8mm, ls2=7.5mm; the copper sheets and groove sizes used by the patches on the upper left, upper right, lower left and lower right of the patch located in the center are: w3=12.5mm, ws3=1.5mm, ls3=5mm. The spacing between the three groups of patches is specifically: g1=1mm, g2=1.6mm. The dielectric substrate material is F4B (εr=2.55, tan δ= 0.002), and the substrate size is 60mm×60mm×2.8mm. The back of the dielectric substrate is fully copper-clad to act as a metal reflective ground. The antenna feeding method adopts coaxial backfeeding, specifically, the coaxial probe position is connected to the patch numbered 2-5, and the distance between the probe position and the lower boundary of the patch numbered 2-5 is s=1.5mm. Since the operating frequency of the antenna is determined by its electrical size, the axial ratio is determined by the size and phase of its radiated electric field component. By properly adjusting the size of the three sets of directional copper foils, the size of the slots, and the distance between different sets of square copper foils, the electrical size of the antenna and the size and phase delay of the two orthogonal polarization electric field components on the radiating surface can be changed, so the operating frequency and axial ratio of the antenna can be flexibly controlled.

[0022] The back of the dielectric substrate is fully copper-clad as a metal reflective ground. The antenna feeding method adopts coaxial backfeeding, specifically, the coaxial probe position is connected to the patch numbered 2-5, and the distance between the probe position and the lower boundary of the patch numbered 2-5 is s=1.5mm.

[0023] The reflection coefficient curve of the antenna can also be obtained through three-dimensional electromagnetic simulation software, such as Figure 3 When the value reaches below -10dB at 4.5-6.6GHz, the relative bandwidth value is about 37.8%, reaching a relatively wide bandwidth level. Figure 4The axial ratio bandwidth and in-band gain of the antenna are shown. It can be observed that the bandwidth where the antenna axial ratio is less than 3dB is 4.8GHz-5.8GHz (relative bandwidth is 18.8%), and the radiation gain range of the antenna within this bandwidth is 8.4dBi-10.5dBi.

[0024] Figure 5 The radiation patterns of the array at three frequencies of 4.8 GHz, 5.3 GHz, and 5.8 GHz are given respectively. It can be seen that the proposed antenna has a good directional radiation pattern.

Claims

1. A high-gain broadband circularly polarized microstrip antenna, comprising a dielectric substrate, a radiation patch printed on the dielectric substrate, and a reflective ground printed on the back of the dielectric substrate, characterized in that: The radiation patch is composed of three groups of nine patches of different sizes. Grooves of different lengths and widths are etched in the central 45° direction of each patch to generate circular polarization of different frequencies.

2. The high-gain broadband circularly polarized microstrip antenna according to claim 1, characterized in that: The three groups of nine patches of different sizes are arranged in three rows and three columns, wherein the patches above, below, left and right of the patch located in the center have the same size and groove structure; the patches on the upper left, upper right, lower left and lower right of the patch located in the center have the same size and groove structure.

3. According to the high-gain broadband circularly polarized microstrip antenna of claim 1, the reflective ground is made of copper.

4. According to the high-gain broadband circularly polarized microstrip antenna described in claim 1, the feeding method of the high-gain broadband circularly polarized microstrip antenna adopts a coaxial back-feeding form, specifically, the coaxial probe position is connected to the copper foil on the back side of the patch located in the center, and the distance between the probe position and the lower boundary of the patch in the center is s=1.5mm.

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