Broadband dual-circular-polarization full-duplex patch antenna

Abstract

The invention provides a broadband dual-circularly-polarized full-duplex patch antenna which comprises a two-port feed network, a 0.762 mm thick dielectric plate, a metal floor, an air layer, a 0.508 mm thick dielectric plate, a right-handed circularly-polarized radiation unit, a left-handed circularly-polarized radiation unit and a grounding metal column. The metal floor is arranged on the upper surface of the 0.762 mm thick dielectric plate; four rectangular feed slots with the same size, a quadrangular star-shaped slot and three rectangular slots are formed in the metal floor; the air layer is arranged between the metal floor and the medium plate with the thickness of 0.508 mm; the left-handed circularly polarized wave radiation patch and the right-handed circularly polarized wave radiation patch are stepped radiation patches and are symmetrically arranged on the upper surface of the medium plate with the thickness of 0.508 mm. The stepped antenna is used as an antenna unit, a new circular polarization mode is introduced, the axial ratio bandwidth of the antenna is greatly improved, meanwhile, a decoupling structure composed of a defected ground and a grounding metal column is used, coupling between the transmitting antenna and the receiving antenna is effectively reduced, the 3dB gain bandwidth of the antenna is widened under the condition that impedance matching and axial ratio change are not large, and the antenna performance is improved. And meanwhile, the isolation degree is obviously improved.

Description

Technical Field

[0001] The invention belongs to the technical field of antennas, and in particular relates to a broadband dual circular polarization full-duplex patch antenna. Background Art

[0002] With the rapid development of wireless communication technology, wireless spectrum resources are almost exhausted. At the same time, the same-frequency full-duplex technology can make more full use of limited spectrum resources. Circularly polarized antennas have the advantages of anti-multipath interference and good polarization matching, and have broad application prospects in satellite communication systems, radar systems and radio frequency identification. Circularly polarized patch antennas have aroused widespread research interest due to their low profile, easy processing and low cost.

[0003] The working bandwidth of circularly polarized full-duplex antennas needs to meet the requirements of impedance matching, axial ratio, gain, etc. Therefore, generally speaking, when a certain degree of isolation is achieved, the working bandwidth of circularly polarized full-duplex antennas is relatively narrow, which makes it difficult to meet the requirements of broadband wireless communication systems; and wide-bandwidth full-duplex antennas are generally linearly polarized antennas, which are easily interfered by multipath effects and cannot meet the working requirements of some scenarios; circularly polarized full-duplex patch antennas may also have the problem of low gain. Circularly polarized full-duplex patch antennas with broadband, high isolation, and high gain are rarely reported. The following is an introduction to some of the published patents: The invention patent application with Chinese patent publication number CN115799827A discloses a circularly polarized compact full-duplex antenna and wireless communication device. The antenna achieves filtering effect and high isolation by placing short-circuit pins in a ring at the center of the transmitting antenna radiation patch and at the edge of the receiving antenna radiation patch, but the transmitting antenna and the receiving antenna of the antenna cannot work at the same frequency and only have circular polarization in the high frequency band. The invention patent application with Chinese patent publication number CN113078482A discloses a C-band dual-port circularly polarized high-isolation antenna array. The antenna connects 16 radiating elements through a full-duplex feeding network to achieve dual circular polarization of the transceiver antenna. The dual ports have high port isolation, but the antenna uses a complex feeding network, has a narrow impedance bandwidth, and a narrow 3dB axial ratio bandwidth. The invention patent application with the Chinese patent publication number CN113328255A discloses a low-profile dual-port high-isolation dual circular polarization antenna array. The antenna achieves dual-port co-directional circular polarization and high isolation of the dual ports by using a full-duplex feeding network composed of a 180° hybrid network and a 180° balun, but the dual-port common 3dB axial ratio relative bandwidth of the antenna is only 0.69% (5.77GHz-5.81GHz), and the 10dB impedance relative bandwidth is only 3.8% (5.66GHz-5.88GHz). Summary of the invention

[0004] In view of the problems in the background technology, the present invention has developed a broadband dual circularly polarized full-duplex patch antenna, the purpose of which is to use a simple antenna unit, feeding structure and decoupling structure to simultaneously achieve the working requirements of broadband, high gain and dual-port high isolation, so as to meet the simultaneous and same-frequency operation of dual circular polarization.

[0005] To achieve the above object, the present invention adopts the following technical solution: A broadband dual circular polarization full-duplex patch antenna, comprising a two-port feeding network, a 0.762mm thick dielectric plate, a metal floor, an air layer, a 0.508mm thick dielectric plate, a right-hand circular polarization radiating unit, a left-hand circular polarization radiating unit and a grounded metal column; the two-port feeding network is arranged on both sides of the lower surface of the 0.762mm thick dielectric plate, and the feeding network is respectively connected to an excitation port; the metal floor is arranged on the upper surface of the 0.762mm thick dielectric plate, and the metal floor is provided with four rectangular feeding slots of the same size, a four-pointed star slot and Three rectangular slots, wherein the rectangular feeding slot is located around the metal floor, the four-pointed star slot is located in the middle of the metal floor, and the rectangular slots are located on the metal floor in sequence along the symmetry axis of the antenna; the air layer is arranged between the metal floor and the 0.508mm thick dielectric plate; the right-handed circularly polarized wave radiation patch and the left-handed circularly polarized wave radiation patch are stepped radiation patches, symmetrically arranged on the upper surface of the 0.508mm thick dielectric plate, and the grounding metal column passes through the 0.762mm dielectric plate, the air layer and the 0.508mm dielectric plate.

[0006] Furthermore, of the four rectangular feeding slots of the same size, two are horizontally arranged on both sides of one end of the metal floor, and the other two are vertically arranged on both sides of the other end of the metal floor.

[0007] Furthermore, two of the rectangular grooves are respectively located on both sides of the symmetry axis, and the other rectangular groove passes through the four-pointed star-shaped groove.

[0008] Furthermore, there are 16 grounding metal pillars, which penetrate the 0.762 mm dielectric plate, the air layer and the 0.508 mm dielectric plate and are arranged near the four-pointed star groove and the rectangular groove.

[0009] Furthermore, the right-handed circularly polarized radiation unit and the left-handed circularly polarized radiation unit are both composed of two stepped radiation patches rotated by 38°.

[0010] Furthermore, there are two groups of right-handed circularly polarized radiation units, which are respectively located on the upper and lower sides of the right side of the 0.508 mm thick dielectric plate, and one group is obtained by rotating the other group 90° around the center of the antenna; there are two groups of left-handed circularly polarized radiation units, which are respectively located on the upper and lower sides of the left side of the 0.508 mm thick dielectric plate, and one group is obtained by rotating the other group 90° around the center of the antenna; and the right-handed circularly polarized radiation units and the left-handed circularly polarized radiation units are symmetrically distributed, and when the right-handed (left-handed) circularly polarized antenna part is used as a transmitting antenna, the left-handed (right-handed) circularly polarized antenna part is used as a receiving antenna. Furthermore, the feeding network is connected to the rectangular feeding slot through microstrip lines.

[0011] Compared with the prior art, the present invention has the following beneficial effects: In view of the fact that most of the currently disclosed broadband full-duplex antennas are linearly polarized antennas, the present invention uses a stepped antenna with broadband circular polarization performance as an antenna unit, and utilizes two improved T-type power dividers to respectively connect the two antenna units of the transmitting and receiving antennas to realize sequential rotary feeding, thereby achieving broadband operation while satisfying circular polarization.

[0012] In view of the low port isolation or high isolation only in a narrow band in the circularly polarized full-duplex antenna reported in the prior art, the present invention uses a decoupling structure consisting of a defective ground (consisting of a four-pointed star slot and a rectangular slot) and a grounded metal column, which can effectively reduce the coupling between the transmitting and receiving antennas, and widen the antenna 3dB gain bandwidth when the impedance matching and axial ratio do not change much. At the same time, the isolation is significantly improved, and the isolation is achieved to be higher than 25dB within the working bandwidth.

[0013] The transceiver antenna unit of the present invention is a symmetrical antenna unit of the same type, and the transceiver antenna performance is highly similar, so that the -10dB impedance matching bandwidth, 3dB axial ratio bandwidth, and 3dB gain bandwidth of the transceiver antenna are highly overlapped, thereby realizing the same-frequency broadband operation of the circularly polarized full-duplex antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0015] Figure 2 It is a side view of the present invention.

[0016] Figure 3 It is a top view of the present invention.

[0017] Figure 4 is the S parameter of the antenna of the present invention.

[0018] Figure 5 This is an axial ratio curve diagram of the antenna of the present invention.

[0019] Figure 6The gain comparison diagram of the present invention with and without the decoupling structure is shown in FIG.

[0020] Figure 7 : This is the radiation pattern of the XOZ plane at 8.2 GHz when the port 101 of the present invention is excited.

[0021] Figure 8 This is the radiation pattern of the YOZ plane at 8.2 GHz when the port 101 of the present invention is excited.

[0022] Fig. 9 : This is the radiation pattern of the XOZ plane at 15 GHz when the port 101 of the present invention is excited.

[0023] Fig.10 : This is the radiation pattern of the YOZ plane at 15 GHz when the port 101 of the present invention is excited. DETAILED DESCRIPTION

[0024] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation mode, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0025] like Figures 1 to 3 As shown, a broadband dual circularly polarized full-duplex array antenna proposed in the present invention includes a two-port feeding network 100, an excitation port 101, an excitation port 102, a 0.762 mm thick dielectric plate 200, a metal floor 300, an air layer 400, a 0.508 mm thick dielectric plate 500, a right-hand circularly polarized radiation unit 601, and a left-hand circularly polarized radiation unit 602. A two-port feeding network 100 is arranged on the lower surface of a dielectric plate 200 by printing, an excitation port 101 is connected to the two-port feeding network 100, a metal floor 300 is arranged on the upper surface of the dielectric plate 200 by printing, four rectangular feeding slots 301 of the same size are etched on the metal floor 300, a four-pointed star slot 302 is etched in the middle of the metal floor 300, three rectangular slots 303 are etched on the metal floor 300 in sequence along the symmetry axis of the antenna, an air layer 400 is between the metal floor 300 and a 0.508 mm thick dielectric plate 500, sixteen grounding metal columns 701 penetrate the 0.762 mm dielectric plate 200, the air layer 400 and the 0.508 mm dielectric plate 500 and are arranged near the four-pointed star slot 302 and the rectangular slot 303, and a right-handed circularly polarized radiation unit 601 and a left-handed circularly polarized radiation unit 602 are arranged on the upper surface of the dielectric plate 500 by printing. The antenna radiates right-hand (left-hand) circularly polarized waves, wherein the right-hand (left-hand) circularly polarized radiation unit 601 (602) is composed of a stepped radiation patch 601a (602a) and a radiation patch 601b (602b) that are rotated by a certain angle (38°). The right-hand circularly polarized antenna part and the left-hand circularly polarized antenna part are symmetrically distributed. When the right-hand (left-hand) circularly polarized antenna part is used as a transmitting antenna, the left-hand (right-hand) circularly polarized antenna part is used as a receiving antenna. like Figure 3 As shown, when transmitting right-handed (left-handed) circularly polarized waves, the antenna is fed through the excitation port 101 (102), and the energy is transmitted to the two-port feeding network 100. After passing through the feeding network 100, the same power and energy with a phase difference of 90° are transmitted to the two ports. The two ports are then connected to the microstrip line 103, and the energy is coupled to the right-handed (left-handed) circularly polarized radiation unit 601 (602) on the 0.508 mm thick dielectric plate through the rectangular feeding slot 301.

[0026] like Figure 4 As shown in the figure, the frequency range of the antenna two-port common impedance matching below -10dB is 7.02-17.52GHz, the impedance matching relative bandwidth reaches 85.6%, and the isolation is higher than 25dB in the working frequency band. The decoupling structure consists of a four-pointed star slot, a rectangular slot and a metal column. After the decoupling structure is introduced, the dual-port isolation is significantly improved.

[0027] like Figure 5 As shown, the frequency band in which the common axial ratio of the transmitting and receiving antennas is lower than 3dB is 7.94-16.87GHz, and the axial ratio relative bandwidth reaches 72%. like Figure 6 As shown, the antennas for comparison are a dual circular polarization full-duplex antenna without a decoupling structure and a dual circular polarization full-duplex patch antenna with a decoupling structure. Figure 6 ,Before the decoupling structure, the gain of the antenna drops significantly in the 12.24GHz-13.73GHz frequency band, affecting the 3dB gain bandwidth. After the decoupling structure is introduced, the 3dB gain frequency band of the dual circularly polarized full-duplex patch antenna is 6.22-16.24GHz, and the 3dB gain relative bandwidth reaches 89.2%. like Figure 7 and Figure 8 As shown, it is the radiation pattern of the dual circular polarization full duplex patch antenna port 101 at 8.2GHz in the XOZ plane and the YOZ plane. Fig. 9 and Fig.10 As shown, it is the radiation pattern in the XOZ plane and the YOZ plane at 15 GHz when the dual circular polarization full-duplex patch antenna port 101 is excited. The present invention uses a stepped radiating patch antenna as an antenna unit. Compared with the prototype radiating patch with a rectangular shape, the stepped antenna unit introduces a new circular polarization mode, which greatly improves the axial ratio bandwidth of the antenna and lays a good foundation for the broadband operation of the entire full-duplex antenna. At the same time, the antenna unit originally radiates right-handed circularly polarized waves, which can be transformed into left-handed circularly polarized waves after symmetrical operation, which facilitates the realization of dual circular polarization in the present invention.

[0028] The array antenna of the present invention adopts a decoupling structure composed of a defective ground and a metal column to reduce the isolation between the two ports, so that the isolation of the antenna in the working frequency band is maintained above 25dB. At the same time, without affecting the impedance bandwidth and the axial ratio bandwidth, the antenna gain becomes flat, achieving the effect of widening the gain bandwidth by 3dB. The frequency range of the common impedance matching of the two ports of the broadband dual circular polarization full duplex array antenna of the present invention is below -10dB, and the impedance matching relative bandwidth reaches 85.6%; the frequency range of the common axial ratio of the transceiver antenna is below 3dB, and the axial ratio relative bandwidth reaches 72%; the frequency range of the common 3dB gain of the transceiver antenna is 6.22-16.24GHz, and the 3dB gain relative bandwidth reaches 89.2%, and the maximum gain reaches 9.44dBic at 10GHz. In summary, the working frequency band of the antenna of the present invention is 7.94-16.24GHz, and the relative bandwidth reaches 68.7%. The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A broadband dual circular polarization full-duplex patch antenna, characterized in that: The invention comprises a two-port feeding network, a 0.762mm thick dielectric plate, a metal floor, an air layer, a 0.508mm thick dielectric plate, a right-hand circular polarization radiating unit, a left-hand circular polarization radiating unit and a grounded metal column; the two-port feeding network is arranged on both sides of the lower surface of the 0.762mm thick dielectric plate, and the feeding networks are respectively connected with excitation ports; the metal floor is arranged on the upper surface of the 0.762mm thick dielectric plate, and the metal floor is provided with four rectangular feeding slots of the same size, a four-pointed star slot and three rectangular slots, wherein the rectangular feeding slots are arranged around the metal floor, the four-pointed star slot is arranged in the middle of the metal floor, and the rectangular slots are arranged on the metal floor in sequence along the symmetry axis of the antenna; the air layer is arranged between the metal floor and the 0.508mm thick dielectric plate; the right-hand circular polarization wave radiation patch and the left-hand circular polarization wave radiation patch are step-type radiation patches, which are symmetrically arranged on the upper surface of the 0.508mm thick dielectric plate, and the grounded metal column penetrates the 0.762mm dielectric plate, the air layer and the 0.508mm dielectric plate.

2. A broadband dual circular polarization full-duplex patch antenna as claimed in claim 1, characterized in that: Two of the four rectangular feeding slots of the same size are horizontally arranged on both sides of one end of the metal floor, and the other two are vertically arranged on both sides of the other end of the metal floor.

3. A broadband dual circular polarization full-duplex patch antenna as claimed in claim 1, characterized in that: Two of the rectangular grooves are located at two sides of the symmetry axis, and the other rectangular groove passes through the four-pointed star-shaped groove.

4. A broadband dual circular polarization full-duplex patch antenna as claimed in claim 1 or 3, characterized in that: There are 16 grounding metal pillars, which penetrate the 0.762 mm dielectric plate, the air layer and the 0.508 mm dielectric plate and are arranged near the four-pointed star groove and the rectangular groove.

5. A broadband dual circular polarization full-duplex patch antenna as claimed in claim 1, characterized in that: The right-handed circularly polarized radiation unit and the left-handed circularly polarized radiation unit are both composed of two stepped radiation patches rotated by 38 degrees.

6. A broadband dual circular polarization full-duplex patch antenna as claimed in claim 5, characterized in that: There are two groups of right-handed circularly polarized radiation units, which are respectively located on the upper and lower sides of the right side of the 0.508mm thick dielectric plate, and one group is obtained by rotating the other group 90° around the center of the antenna; there are two groups of left-handed circularly polarized radiation units, which are respectively located on the upper and lower sides of the left side of the 0.508mm thick dielectric plate, and one group is obtained by rotating the other group 90° around the center of the antenna; and the right-handed circularly polarized radiation units and the left-handed circularly polarized radiation units are symmetrically distributed.

7. A broadband dual circular polarization full-duplex patch antenna as claimed in claim 1, characterized in that: The feeding networks are connected to the rectangular feeding slots through microstrip lines.

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