Out-of-band high-suppression high-frequency-selectivity filtering patch antenna

Abstract

The invention discloses a filtering patch antenna with out-of-band high suppression and high frequency selectivity. Comprising a dielectric substrate, a radiation patch printed on the front surface of the dielectric substrate, a parasitic branch knot, an air layer, a metal ground, a feed circular hole etched in the metal ground and used for separating a feed short needle from a metal ground plane, the feed short needle inserted into the dielectric substrate, and nylon columns inserted into four corners of the dielectric substrate and the metal ground plane and used for fixing. The structure is simple and compact, the working bandwidth is widened, the out-of-band rejection capability and the frequency selectivity are remarkably enhanced, and the requirement for coexistence of multiple frequency bands is met.

Description

Technical Field

[0001] The invention belongs to the technical field of wireless communications, relates to antenna design, and in particular to a filtering patch antenna with high out-of-band suppression and high frequency selectivity. Background Art

[0002] With the continuous advancement of wireless communication technology, especially in the era of coexistence of 4G and 5G networks, the problem of interference between different frequency bands caused by channel congestion has become more and more serious. In order to effectively deal with the interference of these useless signals, the application of filters has become an indispensable technical means. However, in traditional methods, filters and antennas are usually designed independently and cascaded through transmission lines. This often leads to increased equipment size, increased energy consumption and impedance matching problems, affecting system performance. As key components of the RF front end, the efficient integration of filters and antennas is crucial to reducing these problems and improving communication quality. In order to overcome these problems, the main design method is to integrate the filter and the antenna into a filter antenna. However, the current research on filter antennas still faces the following problems:

[0003] 1. The out-of-band suppression level of the filtering antenna is low, and the actual out-of-band gain of the common filtering antenna cannot be reduced to below -10dB. The out-of-band suppression level of the filtering antenna refers to the ability of the antenna to effectively suppress signals outside the operating frequency band and reduce interference from adjacent or non-related frequency bands. This is very important to ensure the clarity and stability of the communication link. In a crowded spectrum environment, the out-of-band suppression capability can significantly reduce the impact of other wireless services (such as broadcasting, radar, etc.) on the communication signal, thereby improving the signal-to-noise ratio (SNR) and reducing the bit error rate (BER). In addition, good out-of-band suppression also helps to meet strict electromagnetic compatibility (EMC) standards and prevent mutual interference between devices.

[0004] 2. The frequency selectivity of the filtering antenna is poor. The frequency selectivity of the actual gain of the common filtering antenna cannot be increased to 200dB / GHz. The frequency selectivity of the filtering antenna means that the antenna can provide excellent frequency response within a specific operating frequency band, while significantly attenuating the signals in the adjacent frequency bands. This helps to accurately receive or transmit signals within the required frequency band while avoiding unnecessary frequency components. Especially in the case of coexistence of multiple frequency bands, high selectivity can ensure that each frequency band can work independently and efficiently to avoid crosstalk between each other. In addition, it can optimize spectrum utilization and allow tighter channel spacing to support more users and services.

[0005] In order to solve the above problems, many designs have been proposed in recent years. However, most of the existing research studies the two parts separately. For example, high out-of-band suppression is achieved by etching gaps on the filter antenna, stacking patches and other structures. Or parasitic units are introduced during the antenna design process to improve frequency selectivity. Although these methods improve the performance of a single aspect to a certain extent, they often find it difficult to simultaneously meet the dual requirements of high out-of-band suppression and high frequency selectivity. Summary of the invention

[0006] The present invention proposes a high-frequency selectivity out-of-band filtering patch antenna. The overall design uses a simple patch and F4B substrate. This design allows the antenna to be flexibly integrated directly with mobile devices, with a simple structure and excellent performance. The operating frequency band covers the 4G B40 band and the 5G N41 band, which is very suitable for antennas of mobile communication devices that need to be compatible with both 4G and 5G network standards.

[0007] The present invention discloses a filter patch antenna with high out-of-band suppression and high frequency selectivity, and the structure includes the following key features: Compatible with 4G and 5G frequency band design: The antenna supports the 4G B40 frequency band and the 5G N41 frequency band, can achieve excellent impedance matching in these frequency bands, and has high gain characteristics to ensure efficient and stable signal transmission. Radiation zero point technology: By introducing a controllable radiation zero point out of the band, the out-of-band suppression level and frequency selectivity are effectively adjusted to improve signal purity. Cavity model theory technology: The antenna structure and feeding position are designed based on the cavity model theory, and the three-resonance mode is adopted to significantly broaden the working bandwidth. Low-profile design: The antenna structure is compact, uses a single-layer PCB, and is only 2mm thick, which is suitable for the miniaturization requirements of modern mobile devices. Parasitic branch design: By arranging parasitic branches around the antenna body, additional resonance points and radiation zero points can be effectively introduced. L-shaped gap design: By etching an L-shaped gap on the main radiation patch, additional resonance points and radiation zero points can be introduced without affecting the size of the antenna patch. This design helps the antenna to be miniaturized.

[0008] In order to achieve the object of the present invention, the present invention adopts the following scheme:

[0009] A filtering patch antenna with high out-of-band suppression and high frequency selectivity comprises: a dielectric substrate, a radiation patch printed on the front of the dielectric substrate, a parasitic branch, an air layer, a metal ground, a feeding circular hole etched on the metal ground for separating a feeding short pin and the metal ground, a feeding short pin inserted in the dielectric substrate, and nylon columns inserted in the four corners of the dielectric substrate and the metal ground for fixing.

[0010] The radiation patch on the front side of the dielectric substrate comprises a main radiation patch, gaps etched on the main radiation patch and parasitic branches.

[0011] The main radiation patch is etched on the front center of the dielectric substrate with a size of 44.7×44.7×0.036 mm 3 Square metal patch.

[0012] The dielectric substrate has two virtual mutually perpendicular symmetry axes, including a vertical symmetry axis 1 and a horizontal symmetry axis 2, which respectively pass through the center of the dielectric substrate vertically and horizontally.

[0013] The gap is a pair of mirror-symmetrical L-shaped gaps on the etched main radiation patch. The vertical length of the L-shaped gap is 19.2 mm, the horizontal length is 7.8 mm, the vertical side of the L-shaped gap is parallel to the vertical symmetry axis 1, the distance is 8 mm, and the horizontal side of the L-shaped gap faces the edge of the main radiation patch.

[0014] The parasitic branches include T-shaped parasitic branches, U-shaped parasitic branches, and rectangular parasitic branches. The T-shaped parasitic branches include a first T-shaped parasitic branch and a second T-shaped parasitic branch that are mirror-symmetrical on the left and right sides of the main radiation patch on the front of the dielectric substrate, the symmetry axis is the vertical symmetry axis 1, each T-shaped parasitic branch is horizontally mirror-symmetrical about the horizontal symmetry axis 2, and each T-shaped parasitic branch has a width of 5.5 mm, a horizontal length l5 of 15 mm, and a vertical length l4 of 39 mm.

[0015] The U-shaped parasitic branches include a first U-shaped parasitic branch, a second U-shaped parasitic branch, a third U-shaped parasitic branch, and a fourth U-shaped parasitic branch etched between the main radiation patch and the T-shaped parasitic branch. Each U-shaped parasitic branch opens toward the horizontal edge of the dielectric substrate, is 0.5 mm away from the vertical edge of the T-shaped parasitic branch, is 2.5 mm away from the horizontal edge of the T-shaped parasitic branch, and is 9.5 mm away from the edge of the main radiation patch. Each U-shaped parasitic branch has a width of 2 mm, a vertical side length of 17 mm, a horizontal side length of 5 mm, and a gap of 1 mm in the middle.

[0016] The rectangular parasitic branch is a rectangular metal patch etched on the back of the dielectric substrate, and the upper end of the rectangular metal patch is passed through by the feeding short needle. The vertical side length of the rectangular parasitic branch is 21.1 mm, the horizontal side length is 2.4 mm, the upper horizontal side of the rectangular parasitic branch is 43.15 mm away from the upper horizontal side of the dielectric substrate, the lower horizontal side of the rectangular parasitic branch is 55.75 mm away from the lower horizontal side of the dielectric substrate, and the center of the rectangular parasitic branch is on the vertical symmetry axis 1.

[0017] The feed short pin is a metal short pin that passes through the main radiation patch and the feed circular hole, with a length of 6.036 mm and a diameter of 1.5 mm. The center of the feed short pin is 0.9 mm away from the upper horizontal edge of the rectangular parasitic branch.

[0018] The feeding circular hole is a circular hole etched on the metal ground, the center of which is aligned with the center of the feeding short pin, and the diameter of the feeding circular hole is 4.3 mm.

[0019] Preferably, the dielectric substrate has a dielectric constant of 2.2, a loss tangent of 0.007, and a size of 120×120×2 mm. 3 F4B substrate.

[0020] Preferably, the main radiation patch, parasitic branches, metal ground and feeding short pin are all made of metal copper.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] The present invention achieves a three-mode passband and four radiation zeros by cleverly combining parasitic branches and etching gap technology, which not only ensures a simple and compact structure, but also broadens the working bandwidth and significantly enhances the out-of-band suppression capability and frequency selectivity. The present invention can cover the 4G B40 and 5G N41 frequency bands, meeting the needs of multi-band coexistence. The four out-of-band radiation zeros of the present invention are independently controllable, and the out-of-band suppression capability and frequency selectivity can be freely adjusted by adjusting their positions. The out-of-band maximum gain of the present invention is lower than -11.5dB, the out-of-band suppression level is higher than 20.36dB, the low-band selectivity is as high as 262dB / GHz, and the high-band selectivity is as high as 369dB / GHz, which effectively reduces interference with adjacent channels and ensures efficient and stable operation of the wireless communication system. In the present invention, the antenna only needs a single-layer dielectric substrate, and the radiation unit and parasitic branches are arranged on both sides of the dielectric substrate. Traditional designs are usually accompanied by large size and technical complexity, while the present invention achieves a simpler design and a more convenient manufacturing process, thereby effectively reducing production costs and process complexity. This innovation not only maintains excellent out-of-band suppression and frequency selectivity, but also improves the simplicity and manufacturing efficiency of the overall design. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of a filtering patch antenna with high out-of-band suppression and high frequency selectivity of the present invention;

[0024] Figure 2 is a top view of the top of the dielectric substrate of the present invention;

[0025] Figure 3 is a bottom view of the bottom of the dielectric substrate of the present invention;

[0026] Figure 4 is a bottom view of the bottom of the metal floor of the present invention;

[0027] Figure 5 is a return loss S parameter simulation curve diagram in a specific embodiment of the present invention;

[0028] Figure 6is a graph of actual gain simulation in a specific embodiment of the present invention;

[0029] Figure 7 It is the radiation pattern simulation of the E plane at 2.45GHz of the present invention;

[0030] Figure 8 It is the radiation pattern simulation of the E plane at 2.45GHz of the present invention;

[0031] Fig. 9 It is a simulation diagram comparing the S parameters and actual gain curves of L-shaped gaps of different sizes according to the present invention;

[0032] Fig.10 The present invention compares the S parameters of rectangular parasitic branches of different sizes and the simulation diagram of the actual gain curve;

[0033] Fig.11 The present invention compares the S parameters of U-shaped parasitic branches of different sizes and the simulation diagram of the actual gain curve;

[0034] Fig.12 The present invention compares the S parameters of T-type parasitic branches of different sizes and the simulation diagram of the actual gain curve;

[0035] Markings in the figure: 1, radiation patch on the front of the dielectric substrate; 11, main radiation patch; 12, L-shaped gap; 121, first L-shaped gap; 122, second L-shaped gap; 13, T-shaped parasitic branch; 131, first T-shaped parasitic branch; 132, second T-shaped parasitic branch; 14, U-shaped parasitic branch; 141, first group of U-shaped parasitic branches; 142, second group of U-shaped parasitic branches; 1411, first group of A U-shaped parasitic branch; 1412, a second U-shaped parasitic branch; 1421, a third U-shaped parasitic branch; 1422, a fourth U-shaped parasitic branch; 2, F4B dielectric substrate; 3, a rectangular parasitic branch; 4, an air layer; 5, a metal ground; 6, a nylon column; 61, a first nylon column; 62, a second nylon column; 63, a third nylon column; 64, a fourth nylon column; 7, a feeding short pin; 8, a feeding circular hole. DETAILED DESCRIPTION

[0036] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the invention is further described in detail below with reference to the accompanying drawings and embodiments, but they are not intended to be a basis for limiting the invention in any way.

[0037] A filtering patch antenna with high out-of-band suppression and high frequency selectivity comprises a dielectric substrate 2, a radiation patch 1 printed on the front of the dielectric substrate, parasitic branches, an air layer 4, a metal ground 5, a feeding circular hole 8 etched on the metal ground for separating a feeding short pin and a metal ground plane, a feeding short pin 7 inserted in the dielectric substrate, and nylon columns 6 inserted in the four corners of the dielectric substrate and the metal ground plane for fixing.

[0038] The radiation patch on the front of the dielectric substrate includes a main radiation patch, a gap etched on the main radiation patch, and a parasitic branch; the main radiation patch 11 is a square metal patch etched in the center of the front of the dielectric substrate. The dielectric substrate has two virtual mutually perpendicular symmetry axes, including a vertical symmetry axis 1 and a horizontal symmetry axis 2, which pass through the center of the dielectric substrate vertically and horizontally respectively.

[0039] The gap 12 is a pair of mirror-symmetrical L-shaped gaps 12 etched on the main radiation patch 11. The vertical length of the L-shaped gap 12 is 19.2 mm, and the horizontal length is 7.8 mm. The vertical side of the L-shaped gap 12 is parallel to the vertical symmetry axis 1 at a distance of 8 mm, and the horizontal side of the L-shaped gap 12 faces the edge of the main radiation patch 11.

[0040] The parasitic branches include T-shaped parasitic branches 13, U-shaped parasitic branches 14, and rectangular parasitic branches 3. The T-shaped parasitic branches 13 include a first T-shaped parasitic branch 131 and a second T-shaped parasitic branch 132, which are mirror-symmetrical on the left and right sides of the main radiation patch on the front of the dielectric substrate, and the symmetry axis is the vertical symmetry axis 1. Each T-shaped parasitic branch is horizontally mirror-symmetrical about the horizontal symmetry axis 2. Each T-shaped parasitic branch has a width of 5.5 mm, a horizontal length l5 of 15 mm, and a vertical length l4 of 39 mm.

[0041] The U-shaped parasitic branch 14 includes a first U-shaped parasitic branch 1411, a second U-shaped parasitic branch 1412, a third U-shaped parasitic branch 1421, and a fourth U-shaped parasitic branch 1422, each of which is etched between the main radiation patch and the T-shaped parasitic branch. Each U-shaped parasitic branch opens toward the horizontal edge of the dielectric substrate, is 0.5 mm away from the vertical edge of the T-shaped parasitic branch, is 2.5 mm away from the horizontal edge of the T-shaped parasitic branch, and is 9.5 mm away from the edge of the main radiation patch. Each U-shaped parasitic branch has a width of 2 mm, a vertical side length of 17 mm, a horizontal side length of 5 mm, and a gap of 1 mm in the middle.

[0042] The rectangular parasitic branch 3 is a rectangular metal patch etched on the back of the dielectric substrate, and the upper end of the rectangular metal patch is passed through by the feeding short needle 7. The vertical side length of the rectangular parasitic branch 3 is 21.1 mm, the horizontal side length is 2.4 mm, the upper horizontal side of the rectangular parasitic branch 3 is 43.15 mm away from the upper horizontal side of the dielectric substrate, the lower horizontal side of the rectangular parasitic branch 3 is 55.75 mm away from the lower horizontal side of the dielectric substrate, and the center of the rectangular parasitic branch 3 is on the vertical symmetry axis 1.

[0043] The feed short pin is a metal short pin that passes through the main radiation patch and the feed circular hole, with a length of 6.036 mm and a diameter of 1.5 mm. The center of the feed short pin is 0.9 mm away from the upper horizontal edge of the rectangular parasitic branch 3.

[0044] The feeding circular hole 8 is a circular hole etched on the metal ground, the center of which is aligned with the center of the feeding short pin, and the diameter of the feeding circular hole 8 is 4.3 mm.

[0045] Preferably, the dielectric substrate 2 has a dielectric constant of 2.2, a loss tangent of 0.007, and a size of 120×120×2 mm. 3 F4B substrate.

[0046] Preferably, the main radiation patch 11, parasitic branches, metal ground and feeding short pin 7 are all made of metal copper.

[0047] Preferably, the size of the main radiation patch 11 is 44.7×44.7×0.036 mm. 3 of patches.

[0048] Preferably, the total length of the first L-shaped slot 121 and the second L-shaped slot 122 corresponds to the radiation zero point f n1 Half the wavelength.

[0049] Preferably, the length of the rectangular parasitic branch 3 is the length corresponding to the radiation zero point f n2 One quarter of the wavelength.

[0050] Preferably, the half arm length of the T-shaped parasitic branch 13 is the length corresponding to the radiation zero point f n3 Half the wavelength. The half arm length is l4 / 2+l5.

[0051] Preferably, the total length of the U-shaped parasitic branch 14 is n4 Half the wavelength.

[0052] Preferably, the air layer 4 is located between the dielectric substrate and the metal ground, and has a height of 4 mm.

[0053] Preferably, the nylon columns 6 are distributed at the four corners of the dielectric substrate, 5 mm away from the nearest edge of the dielectric substrate, made of PA66, with a diameter of 3 mm and a height of 12 mm, and are used to fix the dielectric substrate and the metal floor to ensure the stability and reliability of the structure.

[0054] like Figures 1 to 4 In order to meet the application of antennas in various mobile communication devices, the dielectric substrate 2 adopts an F4B substrate with a dielectric constant of 2.2 and a loss tangent of 0.007. The dielectric substrate is a rectangular body with a length of 120 mm, a width of 120 mm, and a height of 2 mm.

[0055] The main radiation patch, parasitic branches, metal ground and feeding short pin are all made of metal copper.

[0056] The radiation patch printed on the front of the dielectric substrate includes a main radiation patch, a gap and a parasitic branch. The main radiation patch 11 is a square metal patch etched in the center of the front of the dielectric substrate. The gap is a pair of mirror-symmetrical L-shaped gaps 12 etched on the main radiation patch. The parasitic branches include T-shaped parasitic branches 13 and U-shaped parasitic branches 14. The T-shaped parasitic branches 13 include a first T-shaped parasitic branch 131 and a second T-shaped parasitic branch 132 located on the left and right sides of the main radiation patch on the front of the dielectric substrate. The U-shaped parasitic branch 14 includes a first U-shaped parasitic branch 1411, a second U-shaped parasitic branch 1412, a third U-shaped parasitic branch 1421, and a fourth U-shaped parasitic branch 1422 located between the main radiation patch and the T-shaped parasitic branch.

[0057] The radiation patch printed on the back of the dielectric substrate is a rectangular parasitic branch 3. The rectangular parasitic branch is a rectangular metal patch etched on the back of the dielectric substrate, and the upper end of the rectangular metal patch is passed through by a feeding short pin 7.

[0058] The slot and the parasitic branch are both filtering structures that can generate radiation zero points. The L-shaped slot 12 and the rectangular parasitic branch 3 can also each generate a resonance point to broaden the antenna bandwidth.

[0059] The nylon column 6 is made of PA66 material and is used to fix the dielectric substrate and the metal ground to ensure the stability and reliability of the structure.

[0060] The feeding short pin is a metal short pin 7 that passes through the dielectric substrate and the metal ground and is used to connect the radiation patch and the feeding circular hole.

[0061] The feeding circular hole is a circular hole 8 etched on the metal ground, and the center of the circular hole is aligned with the center of the feeding short pin.

[0062] like Figure 5 From the return loss S parameter simulation curve, it can be seen that the antenna of the present invention uses a three-resonance mode to broaden the bandwidth. The antenna of the present invention has a -10dB impedance bandwidth of 17.7%, and the operating frequency band is between 2.26 and 2.7GHz, which can effectively cover the 4GB40 band and the 5G N41 band. The first resonance point f z1 The L-shaped gap increases the current path of the main radiation patch and generates a second resonance point f at a low frequency. z2 The second resonance point at low frequency is f z2 The L-shaped slot is generated by increasing the current path of the main radiation patch. The third resonance point f at high frequency z3 The L-shaped slot is created by increasing the current path of the main radiating patch.

[0063] like Figure 6It can be seen from the actual gain simulation curve that the antenna of the present invention adopts a four-radiation null mode for out-of-band filtering. The peak gain of the antenna of the present invention is 8.86dBi, the maximum out-of-band gain is -11.5dBi, and the out-of-band suppression level is higher than 20.36dB. The low-band frequency selectivity of the antenna of the present invention is 262dB / GHz, and the high-band frequency selectivity is 369dB / GHz. It can be seen that the antenna of the present invention can have both excellent out-of-band suppression performance and frequency selectivity.

[0064] like Figures 7 and 8 , respectively, the radiation patterns of the E-plane and H-plane of the filtering antenna simulated at 2.45GHz are shown, indicating that the proposed antenna has good broadside radiation, and the main polarization field in the maximum radiation direction is 50dB and 16.8dB higher than the cross-polarization field, respectively.

[0065] like Figures 9 to 12 , respectively showing the S parameters and actual gain curve comparisons of four different sizes of filtering antenna structures. The four radiation zero points used in the out-of-band filtering of the antenna of the present invention can be independently controlled, and the low-frequency resonance point and high-frequency resonance point in the band can be independently controlled. These results show that adjusting different structural sizes can effectively control the frequency selectivity of the antenna while optimizing the bandwidth and out-of-band suppression capability, thereby achieving better performance.

[0066] Fig. 9 The simulation results of the comprehensive influence of L-shaped slots of different sizes on S parameters and actual gain curves in the present invention are shown. By comparative analysis, it can be seen that increasing the size of the L-shaped slot l1 will not only reduce the second resonance point f z2 The frequency and significantly broaden the bandwidth, while also reducing the first radiation zero point f n1 frequency, but has almost no effect on the frequencies of the other three radiation zero points.

[0067] Fig.10 The simulation results of the comprehensive influence of rectangular parasitic branches of different sizes on S parameters and actual gain curves in the present invention are shown. By comparing the S parameter curves, it can be seen that increasing the size of the rectangular parasitic branches l2 will reduce the antenna's low-frequency third resonance point f z3 By comparing the actual gain curve, we can see that as the size of l2 increases, the second radiation zero point f n2 From the third radiation zero point f n3 The high frequency position on the right gradually moves to the low frequency position on the left, while the frequency positions of the other three radiation zero points remain almost unchanged. This change shows that the second radiation zero point f n2 It is also independently controllable.

[0068] Fig.11The simulation results of the comprehensive influence of different sizes of U-shaped parasitic branches on S parameters and actual gain curves in the present invention are shown. It can be seen from the S parameter curve that changing the size of the U-shaped slot l3 will not affect the antenna resonance point, and the bandwidth remains unchanged. By comparing the actual gain curve, it can be seen that as the size of l3 gradually decreases, the third radiation zero point f n3 It gradually moves to the high frequency position, and the gain suppression effect at the radiation zero point is also enhanced. This shows that reducing the size of l3 can not only adjust the position of the third radiation zero point, but also effectively improve the gain suppression performance at this frequency point, and almost does not affect other radiation zero points.

[0069] Fig.12 The simulation results of the combined effects of different sizes of T-shaped parasitic branches on S parameters and actual gain curves in the present invention are shown. It can be seen from the S parameter curve that changing the size of the T-shaped slot l4 will not affect the antenna resonance point, and the bandwidth remains unchanged. By comparing the actual gain curve, it can be seen that the fourth radiation zero point f n4 is also independently controllable. As the size of l4 increases, the fourth radiation zero point f n4 Gradually moving to the low-frequency position, the low-frequency out-of-band suppression capability is improved while almost not affecting other radiation zero points.

[0070] The present invention designs a novel low-profile MIMO antenna through characteristic mode theory analysis. The antenna patch is designed through characteristic mode theory, and a ground short pin is added to enable the antenna to achieve high isolation without adding a decoupling structure that affects the size of the antenna. The above simulation and test results verify that the antenna can achieve the advantages of miniaturization, simple structure and high isolation. Various performance indicators are good, which is in line with the current development trend of antennas and can be applied to 5G communications of mobile devices and other related fields.

[0071] The present invention has a high out-of-band suppression and high frequency selectivity filtering patch antenna that cleverly combines parasitic branches and etched gap technology to achieve a three-mode passband and four radiation zeros. The above simulation results verify that the antenna of the present invention can achieve the advantages of simple and compact structure, strong out-of-band suppression capability, and excellent frequency selectivity. It has good performance indicators and is in line with the current development trend of antennas. It can be applied to mobile communication devices that need to be compatible with both 4G and 5G network standards.

[0072] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

Claims

1. A filter patch antenna with high out-of-band suppression and high frequency selectivity, characterized in that: include: A dielectric substrate (2), a radiation patch (1) printed on the front of the dielectric substrate, a parasitic branch, an air layer (4), a metal ground (5), a feeding circular hole (8) etched on the metal ground for separating a feeding short pin and a metal ground plane, a feeding short pin (7) inserted in the dielectric substrate, and nylon columns (6) inserted in the four corners of the dielectric substrate and the metal ground plane for fixing.

2. The out-of-band high-suppression high-frequency selectivity filtering patch antenna according to claim 1, characterized in that: The radiation patch on the front side of the dielectric substrate comprises a main radiation patch (11), gaps etched on the main radiation patch, and parasitic branches; The main radiation patch (11) is etched on the front center of the dielectric substrate (2) with a size of 44.7×44.7×0.036 mm. 3 Square metal patch.

3. The out-of-band high-suppression and high-frequency-selective filtering patch antenna according to claim 2, characterized in that: The dielectric substrate (2) has two virtual mutually perpendicular symmetry axes, including a vertical symmetry axis 1 and a horizontal symmetry axis 2, which respectively pass through the center of the dielectric substrate vertically and horizontally; The slits are a pair of mirror-symmetrical L-shaped slits (12) on the etched main radiation patch (11), the vertical length of the L-shaped slits (12) is 19.2 mm, the horizontal length is 7.8 mm, the vertical side of the L-shaped slits (12) is parallel to the vertical symmetry axis 1, the distance is 8 mm, and the horizontal side of the L-shaped slits (12) faces the edge of the main radiation patch 11.

4. The out-of-band high suppression and high frequency selectivity filtering patch antenna according to claim 3, characterized in that: The parasitic branches include T-shaped parasitic branches (13), U-shaped parasitic branches (14) and rectangular parasitic branches (3); The T-shaped parasitic branch (13) comprises a first T-shaped parasitic branch (131) and a second T-shaped parasitic branch (132) which are mirror-symmetrical on the left and right sides of the main radiation patch on the front side of the dielectric substrate, the symmetry axis is a vertical symmetry axis 1, each T-shaped parasitic branch is horizontally mirror-symmetrical about a horizontal symmetry axis 2, each T-shaped parasitic branch has a width of 5.5 mm, a horizontal length l5 of 15 mm, and a vertical length l4 of 39 mm; The U-shaped parasitic branch (14) comprises a first U-shaped parasitic branch (1411), a second U-shaped parasitic branch (1412), a third U-shaped parasitic branch (1421) and a fourth U-shaped parasitic branch (1422) located between the main radiation patch and the T-shaped parasitic branch, each U-shaped parasitic branch opening faces the horizontal edge of the dielectric substrate, is 0.5 mm away from the vertical edge of the T-shaped parasitic branch, is 2.5 mm away from the horizontal edge of the T-shaped parasitic branch, and is 9.5 mm away from the edge of the main radiation patch; each U-shaped parasitic branch has a width of 2 mm, a vertical side length of 17 mm, a horizontal side length of 5 mm, and a middle gap of 1 mm; The rectangular parasitic branch (3) is a rectangular metal patch etched on the back of the dielectric substrate, and the upper end of the rectangular metal patch is penetrated by the feeding short needle (7); the vertical side length of the rectangular parasitic branch (3) is 21.1 mm, the horizontal side length is 2.4 mm, the upper horizontal side of the rectangular parasitic branch (3) is 43.15 mm away from the upper horizontal side of the dielectric substrate, the lower horizontal side of the rectangular parasitic branch (3) is 55.75 mm away from the lower horizontal side of the dielectric substrate, and the center of the rectangular parasitic branch (3) is on the vertical symmetry axis 1.

5. The out-of-band high suppression and high frequency selectivity filtering patch antenna according to claim 4, characterized in that: The feeding short needle (7) is a metal short needle that passes through the main radiation patch and the feeding circular hole, with a length of 6.036 mm and a diameter of 1.5 mm; the center of the feeding short needle (7) is 0.9 mm away from the upper horizontal edge of the rectangular parasitic branch 3; The feeding circular hole (8) is a circular hole etched on the metal ground, the center of which is aligned with the center of the feeding short pin, and the diameter of the feeding circular hole (8) is 4.3 mm.

6. The out-of-band high-suppression and high-frequency-selective filtering patch antenna according to claim 5, characterized in that: The dielectric substrate (2) has a dielectric constant of 2.2, a loss tangent of 0.007, and a size of 120×120×2 mm. 3 F4B substrate; The main radiation patch (11), parasitic branches, metal ground (5) and feeding short pin (7) are all made of metal copper.

7. The out-of-band high suppression and high frequency selectivity filtering patch antenna according to claim 6, characterized in that: The total lengths of the first L-shaped slot (121) and the second L-shaped slot (122) are both corresponding to the radiation zero point f n1 half the wavelength; The length of the rectangular parasitic branch (3) corresponds to the radiation zero point f n2 One quarter of a wavelength; The half arm length of the T-shaped parasitic branch (13) corresponds to the radiation zero point f n3 Half the wavelength, where the half arm length is l4 / 2+l5; The total length of the U-shaped parasitic branch (14) corresponds to the radiation zero point f n4 Half the wavelength.

8. The out-of-band high-suppression and high-frequency-selective filtering patch antenna according to claim 7, characterized in that: The air layer (4) is located between the dielectric substrate and the metal ground, and has a height of 4 mm; The nylon columns (6) are distributed at the four corners of the dielectric substrate, 5 mm away from the nearest edge of the dielectric substrate, made of PA66, with a diameter of 3 mm and a height of 12 mm, and are used to fix the dielectric substrate and the metal ground plane.

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