A miniaturized high-pass filtering dual-polarized patch antenna

Abstract

The present invention discloses a miniaturized high-pass filtering dual-polarized patch antenna, comprising a reflective floor, a first metal sheet and a second metal sheet. The first metal sheet and the second metal sheet are both square structures with four corners cut off and a gap in the middle. The reflective floor is a square structure. The gaps in the middle of the two metal sheets are formed by a combination of a square and a cross structure; the square gap and the cross gap are both located in the center of the metal sheet, the four branches of the cross gap and the four corners of the square gap point to the edge center of the metal sheet, the size of the cross gap is close to the edge of the metal sheet, and the patch antenna feeds the first metal sheet through four centrosymmetric metal probes. The present invention can achieve a good high-pass filtering effect and a high-pass filtering effect by digging gaps in the center of the parasitic patch and the feeding patch, and can also change the equivalent path of the current on the radiation patch, thereby achieving a miniaturized effect.

Description

Technical Field

[0001] The present invention relates to the field of radio frequency communication, and in particular to a miniaturized high-pass filtering dual-polarization patch antenna. Background Art

[0002] In the field of modern wireless communications, miniaturization and low loss are the development trends of modern RF front-ends. The size and efficiency of traditional single RF front-end devices such as filters, power dividers, antennas, etc. have been studied to near the limit. With the advent of 5G communications, there are more and more communication bands and communication devices. The size and loss of the RF front-end need to be further optimized to meet the needs of future wireless communications. The integrated design of RF front-end devices is an effective solution, especially the integrated design based on antenna arrays and filters.

[0003] The utility model patent with publication number CN201812933U discloses an integrated filtering antenna, which adopts an external circuit solution for filtering and realizes the filtering effect on the antenna. However, this method will bring about insertion loss and size introduced by the additional filter circuit, and the size and efficiency of the entire RF front end are not significantly improved.

[0004] The utility model patent with publication number CN207217766U discloses an omnidirectional low-profile filtering patch antenna, which uses the method of introducing metal vias and circular gaps between the patch and the floor to generate LC resonance to achieve good filtering effect in the low-frequency stopband. Although this filtering antenna does not have the insertion loss and circuit size introduced by the additional filter circuit, the antenna radiator itself needs to be large enough to optimize its radiation and filtering performance. The entire side length reaches 58.4mm (0.86λ), which is relatively large compared to ordinary 0.5λ patch antennas.

[0005] Specific literature such as Chun-Xu Mao, Steven Gao, Yi Wang, Fan Qin, Qing-Xin Chu, "Multimode Resonator-Fed Dual-Polarized Antenna Array With Enhanced Bandwidth and Selectivity," IEEE Trans. Antenna Propag., VOL. 63, NO. 12, DECEMBER 2015, achieves filtering effect by using a stub load resonator (SLR) as the feed for a dual-polarized patch antenna. This method cleverly designs the filter feed network under the floor. Although it solves the problem of the extra size of the filter circuit, it still does not solve the problem of insertion loss introduced by the filter. In addition, the filter antenna is not miniaturized, with a side length of about 0.52λ. Summary of the invention

[0006] In order to overcome the shortcomings and deficiencies of the prior art, the present invention provides a miniaturized high-pass filtering dual-polarized patch antenna. The antenna itself has high-pass filtering performance, the patch side length is only 0.3λ, and the radiation performance and filtering performance of the antenna are very stable.

[0007] The purpose of the present invention is achieved through the following technical solutions: a miniaturized high-pass filtering dual-polarized patch antenna, comprising a reflective floor, a first layer of metal sheet and a second layer of metal sheet, the first layer of metal sheet and the second layer of metal sheet are both square structures with four corners cut off and a gap in the middle, and the reflective floor is a square structure. The present invention can achieve good high-pass filtering effects and high-pass filtering effects by digging gaps in the center of the parasitic patch and the feeding patch. The gap opened in the middle of the two layers of metal sheets can not only achieve the miniaturization of the antenna size, but also move the filtering zero point introduced by the second layer of metal sheet in the high frequency band to the low frequency band, thereby achieving a high-pass filtering response effect.

[0008] Preferably, a gap is opened in the middle of the first layer of metal sheet, and the gap consists of a square gap structure and a cross gap structure, and the square gap structure and the cross gap structure are both located in the center of the first layer of metal sheet.

[0009] Furthermore, the four corners of the square gap structure point to the edge center of the first layer of metal sheet, and the four branches of the cross gap structure also point to the edge center of the first layer of metal sheet and are close to the edge position.

[0010] Preferably, the position of the gap structure opened in the middle of the second metal sheet is the same as that of the gap structure opened in the middle of the first metal sheet.

[0011] Preferably, the size of the gap structure opened in the middle of the second layer of metal sheets is greater than or equal to the size of the gap structure opened in the middle of the first layer of metal sheets.

[0012] Preferably, the side length of the first layer of metal sheets differs from the side length of the second layer of metal sheets by less than 5%.

[0013] Preferably, the first layer of metal sheet is fed by four symmetrical metal probes, and the four metal probes are located on the diagonals of the metal sheet.

[0014] Furthermore, the first metal sheet realizes dual-polarized radiation by simultaneously stimulating differential signals through two probes on the diagonal line.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0016] 1. By digging slits in the center of the parasitic patch and the feed patch, a good high-pass filtering effect can be achieved, and the passband edge has a steep roll-off, while achieving good matching and stable radiation characteristics within the antenna passband.

[0017] 2. By digging gaps in the center of the parasitic patch and the driving patch, the equivalent path of the current on the radiation patch can be changed, thereby achieving a miniaturization effect.

[0018] 3. The distance between the parasitic patch and the driving patch, the size of the parasitic patch and the size of the gap can be adjusted according to actual needs to control the position of the gain suppression zero point and thus change the filtering frequency band.

[0019] 4. It has the characteristics of high isolation, good frequency selectivity, stable radiation pattern, etc.

[0020] 5. The structure is compact and can use PCB processing technology, which is cheap to manufacture; since there is no complex cascade filtering circuit, the loss is low, so the antenna gain is high; and it has dual-polarization radiation characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A top view of the structure of a miniaturized high-pass filtering dual-polarized patch antenna of the present invention;

[0022] Figure 2 The present invention is a side view and a top view of a miniaturized high-pass filtering dual-polarized patch antenna; wherein, FIG (a) is a top view of a parasitic patch of a specific embodiment 1 of the filtering antenna of the present invention; FIG (b) is a side view of a specific embodiment 1 of the filtering antenna of the present invention; FIG (c) is a top view of a feeding patch of a specific embodiment 1 of the filtering antenna of the present invention;

[0023] Figure 3 It is a frequency simulation result diagram of the +45 degree reflection coefficient (S11), -45 degree reflection coefficient (S22) and ±45 degree polarization isolation (S12) of the specific embodiment 1 of the filtering antenna of the present invention;

[0024] Figure 4 is a ±45° gain-frequency simulation result diagram of the specific embodiment 1 of the filtering antenna of the present invention;

[0025] Figure 5 is the radiation pattern of the filtering antenna embodiment 1 of the present invention at 0.9 GHz and +45°;

[0026] Figure 6 The radiation pattern of the filtering antenna of the present invention in specific embodiment 1 at 0.9 GHz and -45°;

[0027] Figure 7The three-dimensional structure diagram of a miniaturized high-pass filtering dual-polarization patch antenna of the present invention.

[0028] Among them, 1-metal reflector, 2-dielectric plate to which the parasitic patch is attached, 3-dielectric plate to which the driving patch is attached, 4-feeding probe, 5-parasitic patch, 6-driving patch, 7-gap on the parasitic patch, 8-gap on the driving patch. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] Example

[0031] like Figures 1 to 2 As shown, this embodiment provides a miniaturized high-pass filtering dual-polarization patch antenna. Figure 1 , Figure 2 , Figure 7 It can be seen that the antenna unit is placed in the middle and upper position of the metal reflector 1, four feeding probes 4 pass through the PCB dielectric plate 3 and are welded to the driving patch 6, one pair of diagonally opposite feeding probes 4 are differentially fed to form +45° linear polarization, and the other pair of diagonally opposite feeding probes 4 form -45° linear polarization.

[0032] The driving patch 6 is printed on the PCB dielectric board 3. A gap 8 is opened at the center of the driving patch 6. The gap 8 is composed of a square structure and a cross structure. The gap 8 changes the current distribution, making the patch antenna miniaturized.

[0033] The parasitic patch 5 is printed on the single-sided PCB dielectric board 2, and a gap 7 is opened at the center of the parasitic patch 5. The shape of the gap 7 is composed of a square structure and a cross structure.

[0034] The PCB dielectric plate 2 is located directly above the PCB dielectric plate 3. By adjusting the sizes of the gaps 7 and 8 and the distance between the PCB dielectric plates 3 and 2, the filtering zero point introduced by the parasitic patch 5 in the high frequency band can be moved to the low frequency band to achieve a high-pass filtering response effect.

[0035] like Figure 3As shown, it is the return loss-polarization isolation-frequency simulation result diagram of this embodiment. The filtering antenna of specific embodiment 1 still has two resonant modes in the 820MHz to 980MHz frequency band, and S11 is below -10dB, achieving good matching of the working frequency band. The polarization isolation in the working frequency band reaches below -37.8dB, achieving good isolation.

[0036] like Figure 4 The figure shows the gain-frequency simulation result of this embodiment. The filter antenna of the specific embodiment 1 has a simulated gain of 8.2dB to 9.09dB in the frequency band of 820MHz to 980MHz. There is a radiation zero point at 730MHz, which achieves relatively good out-of-band suppression.

[0037] like Figure 5 As shown, it is a simulation result diagram of the 900MHz +45° linear polarization pattern of this embodiment, in which the main polarization pattern of the directional pattern is not distorted and has relatively low cross polarization.

[0038] like Figure 6 As shown, it is a diagram of the simulation result of the 900MHz -45° linear polarization pattern of this embodiment, in which the main polarization pattern of the directional pattern is not distorted and has relatively low cross polarization.

[0039] The miniaturized high-pass filter dual-polarized patch antenna described in this embodiment integrates filtering characteristics and radiation characteristics. The antenna itself has filtering performance, steep passband edge, obvious sideband suppression, and good frequency selection characteristics. No external filtering loss circuit is required, which overcomes the shortcomings of large loss and large volume when using an external filtering circuit to design a filtering antenna. The filter passband can cover the 820MHz-960MHz frequency band, and the passband gain is flat, which can achieve higher gain, suppress adjacent frequency interference, and improve the performance of the base station transceiver. At the same time, parasitic patches and cross gaps are introduced, and low-frequency radiation suppression zero points are introduced, so that the gain of the lower frequency band of the passband drops rapidly, and the zero point effect produces high-pass filtering characteristics.

[0040] The entire structure of the miniaturized high-pass filtering dual-polarized patch antenna described in this embodiment is mainly composed of a metal patch, a metallized via, a dielectric plate through hole and a cross-shaped slot. It has a simple structure and a simple design and can be processed using inexpensive PCB technology.

[0041] In summary, the present invention is applicable to the field of multi-frequency base station antennas for wireless mobile communications, and can be applied to receiving and transmitting equipment of various wireless communication systems. Due to the filtering characteristics of the present invention, it is particularly suitable for base station antennas operating at 820-980 MHz in open and complex multi-band and multi-standard communication scenarios. At the same time, benefiting from the integration of filtering characteristics and radiation characteristics, as well as the miniaturization characteristics of the present invention, the present invention is also suitable for the integration and integration of wireless mobile communication system equipment, reducing design requirements and improving the ability of communication equipment to resist adjacent frequency interference.

[0042] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A miniaturized high-pass filtering dual-polarized patch antenna, characterized in that: The reflective floor comprises a first metal sheet and a second metal sheet, wherein the reflective floor, the first PCB dielectric board, the first metal sheet, the second PCB dielectric board and the second metal sheet are arranged in sequence from bottom to top, the first metal sheet and the second metal sheet are both square structures with four corners cut off and gaps in the middle, and the reflective floor is a square structure; A gap is opened in the middle of the first layer of metal sheet, and the gap is composed of a square gap structure and a cross gap structure. The square gap structure and the cross gap structure are both located in the center of the first layer of metal sheet, and the four corners of the square gap structure point to the edge center of the first layer of metal sheet, and the four branches of the cross gap structure also point to the edge center of the first layer of metal sheet and are close to the edge position; the gap structure opened in the middle of the second layer of metal sheet is consistent with the gap structure opened in the middle of the first layer of metal sheet and is located in the same position on the metal sheet; the first layer of metal sheet is fed by four symmetrical metal probes, and the four metal probes are located on the diagonal of the metal sheet. The first layer of metal sheet realizes dual-polarized radiation by simultaneously stimulating differential signals through two probes on the diagonal.

2. The miniaturized high-pass filtering dual-polarized patch antenna according to claim 1, characterized in that: The size of the gap structure opened in the middle of the second layer of metal sheets is greater than or equal to the size of the gap structure opened in the middle of the first layer of metal sheets.

3. The miniaturized high-pass filtering dual-polarized patch antenna according to claim 1, characterized in that: The side length of the first layer of metal sheets differs from the side length of the second layer of metal sheets by less than 5%.

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