A dual-polarized relay antenna based on an adjustable parasitic decoupling structure

Abstract

The application discloses a dual-polarized relay antenna based on an adjustable parasitic decoupling structure, which comprises a decoupling structure vertically arranged on an antenna floor, two completely same cross-dipole antenna arrays arranged on two sides of the decoupling structure, a parasitic scatterer arranged on the decoupling structure, and an adjustable load arranged in the middle of the parasitic scatterer; the port isolation degree, the co-polarization and the cross-polarization isolation degree between the cross-dipole antenna arrays are suppressed by adjusting the decoupling structure and the adjustable load, and the application has the advantages of simple structure, easy realization, low manufacturing cost, obvious co-polarization decoupling effect, good safety and remarkable isolation degree improvement effect.

Description

Technical Field

[0001] This invention relates to the field of microwave antenna technology, and more specifically to a dual-polarized relay antenna based on an adjustable parasitic decoupling structure. Background Technology

[0002] FD antenna systems, or full-duplex antenna systems, require the simultaneous use of the same time slot or frequency slot for transmission and reception during high-data-rate wireless communication. However, because the signals emitted by the transmitter of the device itself interfere with the received signals of interest, FD antenna systems suffer from self-interference problems, which in turn affect the radiation efficiency of the transmitting and receiving antennas and interfere with communication efficiency. This is especially true for repeater antennas, which, considering factors such as polarization and the number of elements, have requirements for indicators such as isolation within the transmitting and receiving antenna elements, as well as isolation between adjacent elements with the same polarization and cross-polarization.

[0003] 2014, Document (YJ Song and K. Sarabandi, "ASimultaneousDual-Channel Micro-Radio-Repeater for Ad-Hoc Wireless Communication", inIEEE In Transactions on Antennas and Propagation, vol. 62, no. 6, pp. 3378-3383, June 2014, a dual-channel subwavelength low-power radio repeater system is introduced. This miniature radio repeater system mainly consists of Tx (transmitting) and Rx (receiving) antennas and RF amplifier circuitry. By feeding two symmetrical Tx antennas with the same amplitude but 180 out-of-phase signals, an electromagnetic null plane is generated between the symmetrically placed Rx antennas. Therefore, the total current at the Rx antenna feed point disappears, resulting in substantial suppression of mutual coupling. Furthermore, since this system achieves this through near-field cancellation, the two transmitting antennas are differentially fed, forming an electromagnetic null plane at the receiving antenna. Therefore, the bipolar decoupling effect is not significant. However, using multiple transmitting antennas would lead to excessively high costs and poor antenna standing wave ratios.

[0004] In 2021, a paper (J.D. Ash and D. Sarkar, “Microstrip Patch Antenna System With Enhanced Inter-Port Isolation for Full-Duplex / MIMO Applications”, in IEEE Access, vol. 9, pp. 156222-156228, 2021.) proposed a tightly spaced dual-port microstrip patch antenna system with significant isolation enhancement (>90 dB), which can be deployed for M... In IMO (Multiple-Input Multiple-Output) systems and full-duplex transceiver systems, a resonant combination of a rectangular defect grounding structure (DGS) and a near-field decoupling structure (NFDS) is deployed near the dual-port microstrip patch antenna system. This reduces port-to-port coupling (<90dB) and helps eliminate self-interference from a full-duplex perspective. The wide-side gain of a single antenna in a dual-port MIMO system is 7.11dBi, the efficiency is 97%, and the cross-polarization level is <25dB. This system uses a resonant combination of a rectangular defect grounding structure (DGS) and a near-field decoupling structure (NFDS), but the near-field decoupling structure is complex and not universally applicable.

[0005] In summary, existing relay antennas have limited decoupling capabilities, with high single-point decoupling frequencies but narrow decoupling bandwidths. Furthermore, bipolar decoupling is not effective and cannot meet the increasing communication demands. Moreover, their structures are too complex, difficult to implement, and lack universality. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention aims to provide a dual-polarized relay antenna based on an adjustable parasitic decoupling structure. By adjusting the decoupling structure and the adjustable load therein, the port isolation, co-polarization, and cross-polarization isolation between cross-dipole antenna arrays are improved. The present invention has the advantages of simple structure, easy implementation, low manufacturing cost, obvious co-polarization decoupling effect, good security, and significant improvement in isolation.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A dual-polarized relay antenna based on an adjustable parasitic decoupling structure includes a decoupling structure 1 vertically mounted on an antenna floor 3, with two identical cross dipole antenna arrays 2 on both sides of the decoupling structure 1.

[0009] The decoupling structure 1 includes an antenna first dielectric substrate 101, a parasitic scatterer 102 is provided above the antenna first dielectric substrate 101, and an adjustable load 103 is provided in the middle of the parasitic scatterer 102. The adjustable load 103 is an RLC circuit element.

[0010] The cross dipole antenna array 2 comprises a plurality of coaxial feed metal posts 203 arranged above the antenna ground plane 3, two cross-distributed coaxial feed inner cores 202 are arranged inside the coaxial feed metal post 203, a plurality of ±45° polarization radiation patches 201 are arranged above the coaxial feed metal post 203, and the upper ends of the two coaxial feed inner cores 202 are connected to the middle part of the ±45° polarization radiation patches 201.

[0011] The two cross dipole antenna arrays 2 are 1*2 cross dipole antenna arrays, the distance between the two cross dipole antenna arrays 2 is 0.5-0.7 times of the wavelength corresponding to the center frequency, preferably 0.68 times, and the distance between the decoupling structure 1 and the cross dipole antenna arrays 2 on both sides thereof is 0.25-0.35 times of the wavelength corresponding to the center frequency, preferably 0.34 times.

[0012] The distance between the bottom of the parasitic scatterer 102 and the antenna ground plane 3 is 0.6-0.7 times of the wavelength corresponding to the center frequency, preferably 0.68 times, and the distance between the bottom of the parasitic scatterer 102 and the plane where the top of the cross dipole antenna array 2 is located is 0.08-0.1 times of the wavelength corresponding to the center frequency, preferably 0.09 times.

[0013] The antenna ground plane 3 is provided with a plurality of feed through holes 301 for coaxial feeding, and the positions of the feed through holes 301 are directly opposite to the bottoms of the coaxial feed inner cores 202.

[0014] The parasitic scatterer 102 is in an "I" shape.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] 1. Since the present invention adopts the structure of the decoupling structure 1 and the two cross dipole antenna arrays 2, the structure is simple, easy to implement, and the manufacturing cost is low.

[0017] 2. By adjusting the decoupling frequency point of the adjustable load 103 in the decoupling structure 1, the co-polarization decoupling effect between the two cross dipole antenna arrays 2 is obvious, which has a significant effect on the improvement of the isolation degree.

[0018] 3. By optimizing the distance between the two cross dipole antenna arrays 2, the distance from the decoupling structure 1 to the two cross dipole antenna arrays 2, the limitation of the distance between the bottom of the parasitic scatterer 102 and the antenna ground plane 3, and the distance between the bottom of the parasitic scatterer 102 and the plane where the top of the cross dipole antenna array 2 is located, a better isolation improvement effect can be obtained.

[0019] 4. By providing a power supply through hole 301, it is convenient to power the coaxial power supply inner core 202, thereby improving the safety of the present invention.

[0020] 5. By setting the parasitic scatterer 102 to an "I" shape, it is convenient to simultaneously decouple the cross dipole antenna arrays 2 on both sides, thereby improving the optimization effect of the isolation of their co-polarization ports.

[0021] In summary, the present invention has the advantages of simple structure, easy implementation, low manufacturing cost, obvious decoupling effect of same polarity, good safety, and significant improvement in isolation. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0023] Figure 2 This is a schematic diagram of the decoupling structure of the present invention.

[0024] Figure 3 This is a schematic diagram of the parasitic scatterer structure of the present invention.

[0025] Figure 4 This is a schematic diagram of the cross dipole antenna array of the present invention.

[0026] Figure 5 This is a schematic diagram of the antenna floor of the present invention.

[0027] Figure 6 The figure shows the simulation results of the VSWR of a single polarized antenna port without decoupling structure in the embodiments of the present invention.

[0028] Figure 7 The figure shows the simulation results of the single-polarization antenna port VSWR when loading the decoupling structure in the embodiment of the present invention.

[0029] Figure 8 This is a simulation result of the isolation between ports of a single polarized antenna without a decoupling structure in an embodiment of the present invention.

[0030] Figure 9 This is a simulation result of the isolation between ports of a single-polarized antenna when the decoupling structure is loaded in an embodiment of the present invention.

[0031] Figure 10 The figure shows the simulation results of the VSWR of all ports of the dual-polarized antenna without the decoupling structure in this embodiment of the invention.

[0032] Figure 11 The figure shows the simulation results of the VSWR of all ports of the dual-polarized antenna when the decoupling structure is loaded in the embodiment of the present invention.

[0033] Figure 12This is a simulation result of the inter-element co-polarization port isolation of the dual-polarized antenna without a decoupling structure in an embodiment of the present invention.

[0034] Figure 13 This is a simulation result diagram of the inter-element co-polarization port isolation of the dual-polarized antenna when the decoupling structure is loaded in an embodiment of the present invention.

[0035] Figure 14 This is a simulation result of the inter-element cross-polarization port isolation of the dual-polarized antenna without a decoupling structure in this embodiment of the invention.

[0036] Figure 15 This is a simulation result diagram of the inter-element cross-polarization port isolation of the dual-polarized antenna when the decoupling structure is loaded in an embodiment of the present invention.

[0037] In the figure, 1 is the decoupling structure, 2 is the cross dipole antenna array, 3 is the antenna ground plane, 101 is the antenna first dielectric substrate, 102 is the parasitic scatterer, 103 is the adjustable load, 201 is the ±45° planned radiating patch, 202 is the coaxial feed core, 203 is the coaxial feed metal pillar, and 301 is the feed through hole. Detailed Implementation

[0038] The structural and working principles of the present invention will be described in detail below with reference to the accompanying drawings.

[0039] like Figure 1 As shown, a dual-polarized relay antenna based on an adjustable parasitic decoupling structure includes a decoupling structure 1 vertically disposed on an antenna floor 3. Two identical cross dipole antenna arrays 2 are provided on both sides of the decoupling structure 1. Due to the use of the decoupling structure 1 and the cross dipole antenna array 2, the structure of the present invention is simple, easy to implement, and has a low manufacturing cost.

[0040] like Figure 2 as well as Figure 3 As shown, the decoupling structure 1 includes an antenna substrate 101, a parasitic scatterer 102 is provided above the antenna substrate 101, and an adjustable load 103 is provided in the middle of the parasitic scatterer 102. The adjustable load 103 is an RLC circuit element. By adjusting the decoupling frequency of the adjustable load 103 in the decoupling structure 1, the decoupling effect of the same pole between the two cross dipole antenna arrays 2 is obvious, and the isolation is significantly improved.

[0041] like Figure 4As shown, the cross-dipole antenna array 2 includes multiple coaxially fed metal pillars 203 welded to the antenna floor 3. Inside each coaxially fed metal pillar 203 are two coaxially fed inner cores 202 arranged in a cross pattern. Above each coaxially fed metal pillar 203 are multiple ±45° planned radiating patches 201. The upper ends of the two coaxially fed inner cores 202 are connected to the middle of the ±45° planned radiating patches 201. The ±45° polarized radiating patches 201 are square ring-shaped metal structures. The radiating structure near the inner side of the square ring-shaped radiator is connected to the antenna floor 3 via a vertical metal arm. The cross-dipole antenna array 2 adopts a coaxially fed form, and the coaxially fed inner cores 202 pass through two through holes at the top of the cross-dipole antenna array 2 and are welded to one of the radiating arms of the dipole.

[0042] The two cross dipole antenna arrays 2 are 1*2 cross dipole antenna arrays. The distance between the two cross dipole antenna arrays 2 is 0.5-0.7 times the wavelength corresponding to the center frequency, preferably 0.68 times. The distance between the decoupling structure 1 and the cross dipole antenna arrays 2 on both sides is 0.25-0.35 times the wavelength corresponding to the center frequency, preferably 0.34 times.

[0043] The distance between the bottom of the parasitic scatterer 102 and the antenna ground plane 3 is 0.6-0.7 times the wavelength corresponding to the center frequency, preferably 0.68 times; the distance between the bottom of the parasitic scatterer 102 and the plane where the top of the cross dipole antenna array 2 is located is 0.08-0.1 times the wavelength corresponding to the center frequency, preferably 0.09 times.

[0044] like Figure 5 As shown, the antenna floor 3 is provided with a plurality of feed through holes 301 for coaxial feeding. The position of the feed through holes 301 is directly opposite the bottom of the coaxial feed inner core 202, which facilitates the feeding of the coaxial feed inner core 202 and improves the safety of the present invention.

[0045] like Figure 3 As shown, the parasitic scatterer 102 is in the shape of an "I", which facilitates the simultaneous decoupling of the cross dipole antenna arrays 2 on both sides, thereby improving the optimization effect of the isolation of their co-polarization ports.

[0046] Figure 6 The figure shows the simulation results of the VSWR of a single polarized antenna port without the decoupling structure 1 in the embodiment of the present invention. The gray shading in the curve represents the required operating frequency band of 3.4-3.6 GHz. The simulation results show that the VSWR of the antenna array without the decoupling structure 1 can meet the requirement of VSWR less than 1.5 in the operating frequency band.

[0047] Figure 7The figure shows the simulation results of the VSWR of a single polarized antenna port when the decoupling structure 1 is loaded in the embodiment of the present invention. The gray shading in the curve represents the required operating frequency band of 3.3-3.6 GHz. The simulation results show that, compared with the case without the decoupling structure 1, the VSWR of the antenna array can still meet the requirement of less than 1.5 in the operating frequency band. It can be concluded that loading the decoupling structure 1 has no negative impact on the VSWR of the antenna port.

[0048] Figure 8 The figure shows the simulation results of the port isolation of a single polarized antenna without the decoupling structure 1 in the embodiment of the present invention. As can be seen from the figure, within the operating frequency band, the port isolation between single polarized antenna elements is greater than 19dB without the decoupling structure 1.

[0049] Figure 9 The figure shows the simulation results of the isolation between ports of a single polarized antenna when decoupling structure 1 is loaded in an embodiment of the present invention. As can be seen from the figure, within the operating frequency band, the isolation between ports of a single polarized antenna element is greater than 45dB. If the isolation bandwidth is calculated to be greater than 50dB, the isolation bandwidth between ports of the element can reach more than 0.15GHz (covering 3.4-3.55GHz), and the maximum isolation at a single frequency point is 90dB. It can be seen that loading decoupling structure 1 can effectively improve the isolation at a single frequency point of a single polarized antenna element.

[0050] Figure 10 The figure shows the simulation results of the standing wave ratio (SWR) of all ports of the dual-polarized antenna without the decoupling structure 1 in this embodiment of the invention. As can be seen from the figure, the gray shading in the curve represents the required operating frequency band of 3.3-3.6 GHz. Without the decoupling structure 1, the SWR of port 1 and port 3 of the cross dipole antenna array 2 can meet the requirement of a SWR of less than 1.5 in the required frequency band, and the SWR of port 2 and port 4 of the cross dipole antenna array 2 can meet the requirement of a SWR of less than 1.6 in the operating frequency band.

[0051] Figure 11 The figure shows the simulation results of the standing wave ratio (SWR) of all ports of the dual-polarized antenna when the decoupling structure 1 is loaded in the embodiment of the present invention. As can be seen from the figure, the gray shading in the figure represents the required operating frequency band of 3.3-3.6 GHz. The simulation results show that the SWR of the cross dipole antenna array 2 can meet the requirement of less than 1.5 in the operating frequency band. By loading the decoupling structure 1, the SWR of the 2-port and 4-port of the cross dipole antenna array 2 can be improved.

[0052] Figure 12 The figure shows the simulation results of the inter-element co-polarization port isolation of the dual-polarized antenna without the decoupling structure 1 in this embodiment of the invention. As can be seen from the figure, the inter-element co-polarization port isolation of the cross dipole antenna array 2 is greater than 19dB in the operating frequency band without the decoupling structure 1.

[0053] Figure 13 The figure shows the simulation results of the inter-element co-polarization port isolation of the dual-polarized antenna when decoupling structure 1 is loaded in the embodiment of the present invention. As can be seen from the figure, within the operating frequency band, the inter-element co-polarization port isolation of the cross dipole antenna array 2 is greater than 48dB. Compared with the case without decoupling structure 1, the inter-element co-polarization port isolation of the cross dipole antenna array 2 is improved by 29dB, and the maximum isolation at a single frequency point can reach 65dB.

[0054] Figure 14 The figure shows the simulation results of the inter-element cross-polarization port isolation of the dual-polarized antenna without the decoupling structure 1 in this embodiment of the invention. As can be seen from the figure, the inter-element cross-polarization port isolation of the cross dipole antenna array 2 is greater than 24dB without the decoupling structure 1.

[0055] Figure 15 This is a simulation result of the inter-element cross-polarization port isolation of the dual-polarized antenna when decoupling structure 1 is loaded in an embodiment of the present invention. As can be seen from the figure, within the operating frequency band, the inter-element cross-polarization port isolation of the cross-dipole antenna array 2 is greater than 36dB. Compared with the case without decoupling structure 1, the inter-element cross-polarization port isolation of the cross-dipole antenna array 2 is improved by 12dB, and the isolation at a single frequency point can reach 47dB.

Claims

1. A dual-polarized repeater antenna based on an tunable parasitic decoupling structure, characterized in that, It includes a decoupling structure (1) vertically mounted on the antenna floor (3), and two identical cross dipole antenna arrays (2) are provided on both sides of the decoupling structure (1). The decoupling structure (1) includes an antenna dielectric substrate (101), a parasitic scatterer (102) is provided above the antenna dielectric substrate (101), the parasitic scatterer (102) is in the shape of "I", the parasitic scatterer (102) is located at the center of the two cross dipole antenna arrays (2), and an adjustable load (103) is provided in the middle of the parasitic scatterer (102). The adjustable load (103) is an RLC circuit element. By adjusting the decoupling frequency of the adjustable load (103) in the decoupling structure (1), it decouples the same pole between the two cross dipole antenna arrays (2). The distance between the bottom of the parasitic scatterer (102) and the antenna floor (3) is 0.6-0.7 times the wavelength corresponding to the center frequency, and the distance between the bottom of the parasitic scatterer (102) and the plane where the top of the cross dipole antenna array (2) is located is 0.08-0.1 times the wavelength corresponding to the center frequency.

2. The dual-polarized repeater antenna based on an tunable parasitic decoupling structure according to claim 1, characterized in that, The cross dipole antenna array (2) includes multiple coaxially fed metal pillars (203) disposed above the antenna floor (3). The coaxially fed metal pillars (203) have two coaxially fed inner cores (202) arranged in a cross pattern inside. Multiple ±45° polarized radiation patches (201) are disposed above the coaxially fed metal pillars (203). The upper ends of the two coaxially fed inner cores (202) are connected to the middle of the ±45° polarized radiation patches (201).

3. A dual-polarized relay antenna based on an tunable parasitic decoupling structure according to claim 1 or 2, characterized in that, The two cross dipole antenna arrays (2) are 1*2 cross dipole antenna arrays. The distance between the two cross dipole antenna arrays (2) is 0.5-0.7 times the wavelength corresponding to the center frequency. The distance between the decoupling structure (1) and the cross dipole antenna arrays (2) on both sides is 0.25-0.35 times the wavelength corresponding to the center frequency.

4. A dual-polarized repeater antenna based on an tunable parasitic decoupling structure according to claim 1, characterized in that, The distance between the bottom of the parasitic scatterer (102) and the antenna floor (3) is 0.68 times the wavelength corresponding to the center frequency, and the distance between the bottom of the parasitic scatterer (102) and the plane where the top of the cross dipole antenna array (2) is located is 0.09 times the wavelength corresponding to the center frequency.

5. A dual-polarized repeater antenna based on an tunable parasitic decoupling structure according to claim 1, characterized in that, The antenna floor (3) is provided with a plurality of feed through holes (301) for coaxial feeding, and the feed through holes (301) are located directly opposite the bottom of the coaxial feed inner core (202).

6. A dual-polarized repeater antenna based on an tunable parasitic decoupling structure according to claim 3, characterized in that, The distance between the two cross dipole antenna arrays (2) is 0.68 times the wavelength corresponding to the center frequency, and the distance between the decoupling structure (1) and the cross dipole antenna arrays (2) on both sides is 0.34 times the wavelength corresponding to the center frequency.

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