Circularly polarized dual-band low-profile antenna for CPE device

Abstract

The application discloses a circularly polarized dual-band low-profile antenna for a CPE device, which adopts four dipole unit arrays to generate horizontal polarization omnidirectional radiation in a low frequency band, and adopts an internal ground circular ring patch structure to generate vertical polarization omnidirectional radiation. The two structures are effectively connected through a coupler, so that omnidirectional circularly polarized radiation characteristics are generated. In a high frequency band, perturbation is introduced by slotting in an elliptical patch, so that directional circularly polarized radiation characteristics are generated. The structures of the two frequency bands are combined through a duplexer, so that a low-profile dual-band circularly polarized antenna is realized. The actual measurement results show that the antenna has good circularly polarized radiation performance in the two frequency bands, and the effectiveness of the antenna structure and design is verified. The circularly polarized antenna is used to replace the traditional linearly polarized antenna, so that the transmission efficiency and quality of the antenna are effectively improved, and the dual-band dual-mode characteristics make the antenna more convenient to use and more widely applied.

Description

Technical Field

[0001] This invention belongs to the field of antenna technology, and particularly relates to a circularly polarized dual-frequency low-profile antenna for CPE equipment. Background Technology

[0002] CPE, short for Customer Premise Equipment, primarily functions as a signal relay. With the rapid development of 5G communication, CPEs are finding applications in numerous communication scenarios. Compared to 3G and 4G, 5G signals have relatively weaker penetration, which is detrimental to the user experience in indoor communication scenarios. Using CPEs allows users to redeploy them according to different usage scenarios and site changes, significantly improving the user experience. The antenna is a key component in a CPE, and its performance determines its communication capabilities. A CPE has multiple communication links, enabling it to communicate with operator base stations and receive base station signals. It can also communicate with various local devices, including mobile phones, computers, televisions, and printers, via Wi-Fi or wired signals. When communicating with a base station, the relatively long distance necessitates a directional beam from the CPE antenna. When communicating with local devices, the uncertain locations of these devices, potentially distributed around the CPE, require an omnidirectional beam from the CPE antenna to simultaneously cover all devices. Linearly polarized antennas achieve maximum transmission efficiency only when the receiving and transmitting antennas are aligned in the same direction, placing certain requirements on the device's location. Circularly polarized antennas, on the other hand, can receive linearly polarized waves from any direction, and their transmitted polarized waves can be received by any linearly polarized antenna. Therefore, in addition to considering the shape of the antenna's radiation beam, circular polarization can effectively suppress multipath effects and improve the stability of wireless communication. Furthermore, designing low-profile antennas to improve the integration density of CPEs is a pressing issue that needs to be addressed. Summary of the Invention

[0003] Purpose of the invention: The purpose of this invention is to provide a circularly polarized dual-frequency low-profile antenna for CPE equipment. This antenna effectively integrates a horizontally polarized omnidirectional structure, a vertically polarized omnidirectional structure, and a directional structure, which is beneficial for the lightweighting and miniaturization of CPE. It can achieve omnidirectional circular polarization radiation characteristics at 2.45 GHz and directional circular polarization radiation characteristics at 5.8 GHz.

[0004] Technical Solution: The present invention provides a circularly polarized dual-band low-profile antenna for CPE equipment, comprising an upper dielectric substrate, a lower dielectric substrate, a circular annular metal patch, an elliptical metal patch, an arc-shaped dipole metal patch, a shorting post, a feed post, and a feed network microstrip metal patch; the arc-shaped dipole metal patch is attached between the upper and lower dielectric substrates; the elliptical metal patch has a square groove in the middle and is attached together with the circular annular metal patch to the upper surface of the upper dielectric substrate; the circular annular metal patch has a shorting post, which connects the circular annular metal patch to the upper surface of the lower dielectric substrate. The patch is connected to the ground plane at the center of the arc-shaped dipole array metal patch; the feed post passes through the upper and lower dielectric substrates to feed the annular and elliptical metal patches respectively; the feed network microstrip metal patch is attached to the lower surface of the lower dielectric substrate and feeds the arc-shaped dipole metal patch through a balun with gap coupling; the feed network microstrip metal patch connects the feed posts of the balun feed, the annular metal patch and the elliptical metal patch through microstrip lines, and realizes single-port feeding and dual-frequency dual-mode operation through a duplexer.

[0005] Furthermore, the short-circuit posts are evenly distributed at equal angles in the middle of the annular metal patch, and the distance from the center of each short-circuit post to the center of the annular metal patch is the same. The annular metal patch is connected to the ground plane at the center of the arc-shaped dipole array metal patch through the short-circuit posts.

[0006] Furthermore, the arc-shaped dipole metal patch includes eight arc-shaped strip-shaped branches, with each pair forming a dipole, for a total of four dipoles. Each dipole is connected to the annular metal patch via a double wire.

[0007] Furthermore, the number of baluns is four.

[0008] Furthermore, the upper and lower dielectric substrates are Rogers-4350b dielectric substrates.

[0009] Furthermore, the thickness of the upper and lower dielectric substrates is 29-31 mil.

[0010] Furthermore, the arc-shaped dipole array metal patch generates horizontal polarization, and the circular metal patch and the arc-shaped dipole array metal patch generate vertical polarization with the same gain at the same frequency. The two generate a 90° phase shift through the coupler in the feed network, forming an omnidirectional circularly polarized antenna.

[0011] Furthermore, the duplexer is model dpx105950dt-6012a1.

[0012] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0013] (1) The present invention provides a low-profile dual-frequency circularly polarized antenna for CPE equipment, which has two radiation modes. For distant base stations, a high-gain directional radiation mode can be used at high frequencies, while for equipment placed at irregular locations around the base stations, an omnidirectional radiation mode can be used at low frequencies, thus providing better coverage of a wider range and ensuring communication stability.

[0014] (2) A low-profile dual-frequency circularly polarized antenna for CPE equipment according to the present invention, wherein the arc-shaped dipole array metal patch generates horizontal polarization, and the circular metal patch and the arc-shaped dipole array metal patch generate vertical polarization with the same gain at the same frequency. The two generate a 90° phase shift through the coupler in the feed network, forming an omnidirectional circularly polarized antenna. Since the transmission efficiency of a linearly polarized antenna can only reach its maximum when the transmission directions of the receiving antenna and the transmitting antenna are consistent, there are certain requirements for the placement of the equipment. However, a circularly polarized antenna can receive linearly polarized waves from any direction, and the transmitted polarized waves can also be received by any linearly polarized antenna. Therefore, in addition to considering the shape of the antenna radiation beam, if the antenna has circular polarization characteristics, it can effectively suppress multipath effects and improve the stability of wireless communication.

[0015] (3) The present invention provides a low-profile dual-frequency circularly polarized antenna for CPE equipment, which has good impedance matching, gain and radiation performance, and has low profile, which reduces the space occupied, improves the integration of CPE, and is conducive to the lightweighting and miniaturization of CPE. Attached Figure Description

[0016] Figure 1 The image shown is a top view of the low-profile dual-frequency circularly polarized antenna structure of the present invention.

[0017] Figure 2 The image shown is a side view of the low-profile dual-frequency circularly polarized antenna structure of the present invention.

[0018] Figure 3 The diagram shows the feed network structure at the bottom of the low-profile dual-frequency circularly polarized antenna of the present invention.

[0019] Figure 4 The diagram shown is a design flowchart of the low-profile dual-frequency circularly polarized antenna feed network of the present invention.

[0020] Figure 5 The image shown is a top view of the low-profile dual-frequency circularly polarized antenna of the present invention, with the actual dimensions marked.

[0021] Figure 6 The image shown is a bottom view of the low-profile dual-frequency circularly polarized antenna of the present invention, with the actual dimensions marked.

[0022] Figure 7 The figure shown is a simulation diagram and a test diagram of the reflection coefficient of the low-profile dual-frequency circularly polarized antenna of the present invention in the 2.45GHz band;

[0023] Figure 8 The figure shown is a simulation diagram and a test diagram of the reflection coefficient of the low-profile dual-frequency circularly polarized antenna of the present invention in the 5.8GHz band;

[0024] Figure 9 The figure shown is a simulation diagram and a test diagram of the axial ratio of the low-profile dual-frequency circularly polarized antenna of the present invention operating near 2.45 GHz in the positive x-axis direction;

[0025] Figure 10 The figure shown is a simulation diagram and a test diagram of the axial ratio of the low-profile dual-frequency circularly polarized antenna of the present invention operating near 5.8 GHz in the positive z-axis direction;

[0026] Figure 11 The diagram shown is a simulation diagram and a test diagram of the low-profile dual-frequency circularly polarized antenna of the present invention operating in the xoy plane of the 2.45GHz band.

[0027] Figure 12 The diagram shown is a simulation diagram and a test diagram of the low-profile dual-frequency circularly polarized antenna of the present invention operating in the yoz plane of the 5.8GHz band.

[0028] Figure reference numerals

[0029] 1-Upper dielectric substrate, 2-Ring-shaped patch, 3-Short-circuit post, 4-Elliptical patch with square slot, 5-Feed post, 6-Arc-shaped dipole array patch, 7-Lower dielectric substrate, 8-Feed network microstrip patch. Detailed Implementation

[0030] The technical solution of the present invention will be further described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0031] like Figures 1-3 As shown, the present invention provides a low-profile dual-frequency circularly polarized antenna for use in CPE equipment, comprising the following contents.

[0032] The upper substrate 1 and lower substrate 7 of the dielectric substrate are Rogers-4350b dielectric substrates, and the thickness of the upper substrate 1 and lower substrate 7 is 30±1mil. The Rogers4350B is a type of imported board material from Rogers in the United States. It is a special board material mainly used in the manufacture of high-frequency circuit boards.

[0033] The annular metal patch 2 is attached to the upper surface of the upper substrate 1, and the elliptical metal patch 4 is attached to the upper surface of the upper substrate 1 and is contained within the annular metal patch.

[0034] The short-circuit post 3 connects the annular metal patch 2 to the ground plane at the center of the arc-shaped dipole array metal patch 6. There are thirty-six short-circuit posts 3, which are evenly distributed at equal angles on the annular patch 2. The center of each short-circuit post 3 is equidistant from the center of the annular metal patch 2.

[0035] The power supply column 5 passes through the upper dielectric substrate 1 and the lower dielectric substrate 7, and supplies power to the annular metal patch 2 and the elliptical metal patch 4 respectively through the power supply network 8.

[0036] The arc-shaped dipole array metal patch 6 is attached between the upper dielectric substrate 1 and the lower dielectric substrate 7, generating horizontal polarization. The circular metal patch 2 and the arc-shaped dipole array metal patch 6 generate vertical polarization with the same gain at the same frequency. The two generate a 90° phase shift through the coupler in the feed network 8, forming an omnidirectional circularly polarized antenna.

[0037] The power supply network 8 is attached to the lower surface of the lower dielectric substrate 7. It provides slot-coupled power supply to the arc-shaped dipole array metal patch through a balun. The power supply pillars of the four balun feeders, the circular metal patch, and the elliptical metal patch are connected through a microstrip line. The duplexer enables single-port power supply and dual-frequency dual-mode operation.

[0038] The short-circuit post 3 and the power supply post 5 are made of conductive materials, and the duplexer uses dpx105950dt-6012a1.

[0039] like Figure 4 As shown, this embodiment is used for information transmission between CPE devices and other devices. First, a single arc dipole was simulated, and the reflection coefficient and radiation gain were adjusted using balun coupling feed. Next, four arc dipoles were arranged into an array, and the overall reflection coefficient and radiation gain were adjusted to make it work at 2.45 GHz. Then, a circular ring antenna with coaxial feed was simulated and made to work at 2.45 GHz. The radiation gains of the two were observed and made consistent. The feed network was used to make the two phases 90° apart, generating omnidirectional circular polarization radiation in the horizontal plane, establishing a good communication link for information transmission between CPE devices and antennas with uncertain positions and radiation directions. Finally, an elliptical antenna that generates directional circular polarization radiation in the vertical plane was simulated. By opening a square slot in the center of the elliptical patch to introduce perturbation, circular polarization was generated. The feed points of the two modes were connected by a duplexer to realize single-port input.

[0040] like Figures 5-6 As shown, the overall dimensions of the antenna are 48.5mm × 48.5mm × 1.524mm. The antenna has a low profile, which makes it easy to integrate with other devices and is beneficial for the lightweighting and miniaturization of CPE.

[0041] like Figures 7-8 As shown in the results, the actual measurement results are in good agreement with the simulation results. When the antenna operates in the 2.45 GHz band, the measured reflection coefficient is less than -10 dB in the range of 2.35–2.48 GHz, corresponding to an impedance bandwidth of 5.31%. When the antenna operates in the 5.8 GHz band, the measured reflection coefficient is less than -10 dB in the range of 5.68–5.9 GHz, corresponding to an impedance bandwidth of 3.79%.

[0042] like Figures 9-10 As shown, at 2.45 GHz, the antenna's axial ratio in the positive x-axis direction is less than 3 dB, exhibiting circular polarization characteristics. At 5.8 GHz, the tested axial ratio value is less than 3 dB in the range of 5.75–5.89 GHz, corresponding to an axial ratio bandwidth of 2.41%.

[0043] like Figure 11 As shown, the radiation pattern of the antenna in the xoy plane at a frequency of 2.45 GHz is given. The test results show that the maximum circular polarization gain of the antenna at a frequency of 2.45 GHz is -1.31 dBi.

[0044] like Figure 12 As shown, the radiation pattern of the antenna on the xoz plane at a frequency of 5.8 GHz is given. The test results show that the maximum circular polarization gain of the antenna at a frequency of 5.8 GHz is 6.8 dBi.

[0045] The above description is merely an exemplary embodiment of the present invention and does not limit the scope of patent protection of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A circularly polarized dual-frequency low-profile antenna for CPE equipment, characterized in that, The system includes an upper dielectric substrate (1), a lower dielectric substrate (7), an annular metal patch (2), an elliptical metal patch (4), an arc-shaped dipole metal patch (6), a short-circuit post (3), a feed post (5), and a feed network microstrip metal patch (8). The arc-shaped dipole metal patch (6) is attached between the upper dielectric substrate (1) and the lower dielectric substrate (7). The elliptical metal patch (4) has a square groove in the middle and is attached to the upper surface of the upper dielectric substrate (1) together with the annular metal patch (2). The elliptical metal patch (4) is located inside the annular metal patch (2). The annular metal patch (2) has a short-circuit post (3), which connects the upper dielectric substrate (1) to the lower dielectric substrate (7). The annular metal patch (2) is connected to the center ground plane of the arc-shaped dipole metal patch (6); the feed post (5) passes through the upper dielectric plate (1) and the lower dielectric plate (7) to feed the annular metal patch (2) and the elliptical metal patch (4) respectively; the feed network microstrip metal patch (8) is attached to the lower surface of the lower dielectric plate (7) and feeds the arc-shaped dipole metal patch (6) through a balun; the feed network microstrip metal patch (8) connects the balun feed, the annular metal patch (2) and the elliptical metal patch (4) feed posts (5) through microstrip lines, and realizes single-port feed and dual-frequency dual-mode operation through a duplexer.

2. The circularly polarized dual-frequency low-profile antenna for CPE equipment according to claim 1, characterized in that, The short-circuit posts (3) are evenly distributed at equal angles in the middle of the annular metal patch (2). The distance from the center of each short-circuit post (3) to the center of the annular metal patch (2) is the same. The annular metal patch (2) is connected to the ground plane at the center of the arc-shaped dipole metal patch (6) through the short-circuit posts (3).

3. The circularly polarized dual-frequency low-profile antenna for CPE equipment according to claim 1, characterized in that, The arc-shaped dipole metal patch (6) includes 8 arc-shaped strip branches, in which every two are paired to form a dipole, forming a total of 4 dipoles. Each dipole is connected to the annular metal patch (2) by a double wire.

4. The circularly polarized dual-frequency low-profile antenna for CPE equipment according to claim 1, characterized in that, The number of baluns is 4.

5. The circularly polarized dual-frequency low-profile antenna for CPE equipment according to claim 1, characterized in that, The upper dielectric substrate (1) and the lower dielectric substrate (7) are Rogers-4350b dielectric substrates.

6. The circularly polarized dual-frequency low-profile antenna for CPE equipment according to claim 1 or 5, characterized in that, The thickness of the upper dielectric plate (1) and the lower dielectric plate (7) is 29-31 mil.

7. The circularly polarized dual-frequency low-profile antenna for CPE equipment according to claim 1 or 3, characterized in that, The arc-shaped dipole metal patch (6) generates horizontal polarization, and the circular metal patch (2) and the arc-shaped dipole metal patch (6) generate vertical polarization with the same gain at the same frequency. The two generate a 90° phase shift through the coupler in the feed network (8) to form an omnidirectional circularly polarized antenna.

8. The circularly polarized dual-frequency low-profile antenna for CPE equipment according to claim 1, characterized in that, The duplexer is model dpx105950dt-6012a1.

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