A filtering antenna and a 5G communication device

Abstract

The present invention discloses a filtering antenna and a 5G communication device, the antenna comprising: an upper dielectric plate and a lower dielectric plate separated by an air gap, a driving patch arranged on the upper dielectric plate and a plurality of parasitic patches, and the plurality of parasitic patches are arranged around the driving patch; a feeder and a plurality of short-circuit branches are arranged on the side of the lower dielectric plate facing away from the upper dielectric plate, and a coupling slot is etched on the other side; the driving patch receives the electric field radiated from the coupling slot, and generates coupled common radiation on the parasitic patch, generating a radiation zero point at the upper edge of the passband; the plurality of short-circuit branches are respectively located at the terminal and both sides of the feeder, and generate absorption zero points at the lower edge of the passband, the out-of-band high-order mode position and the second harmonic position. While ensuring the excellent filtering response of the antenna, the present invention has a suppression degree of 34.6dBc and 31.3dBc at the high-order mode position and the second harmonic position.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and specifically to a filtering antenna and a 5G communication device. Background Art

[0002] With the rapid development of 5G communication technology, the requirements for miniaturization of communication systems are getting higher and higher. Antennas and filters, as passive components at the front end of communication systems, play an important role in achieving signal exchange and system stability. In terms of structure, the increasing requirements for miniaturization have prompted antennas and filters to gradually move towards integration. In terms of communication stability, the development focus of antennas and filters is on high suppression of high-order modes and harmonics outside the passband.

[0003] Products that integrate filters and antennas are called filter antennas. The emergence of filter antennas effectively reduces the size of RF systems and provides strong support for system miniaturization. Among the existing filter antenna products, most only consider the stable transmission of signals within the passband and the suppression of sidebands, and do not consider the suppression of high-order modes and harmonics in the high-frequency direction outside the band. This causes the antenna to strongly interfere with the communication environment when transmitting signals, and also receives unnecessary clutter signals when receiving signals, causing the quality and stability of the communication system to deteriorate.

[0004] Therefore, the current development of filter antennas requires that they have high-order mode and harmonic suppression characteristics while ensuring stability and steep edges within the passband. Most of the existing filter antenna products with high-frequency suppression are designed by integrating a filter structure with a slow-wave structure with an antenna, which makes the design of the filter antenna complex and has low suppression. Therefore, ensuring that the filter antenna has stable filtering performance while also having high high-order mode and harmonic suppression characteristics is one of the difficulties in the current design of filter antennas.

[0005] In the prior art, the invention patent with the patent publication number CN113745837A discloses an omnidirectional, vertically polarized, electrically small filtering antenna. In the patent, the feeder part includes a first branch module and a second branch module, and the first branch module and the second branch module are both arranged on the upper surface of the lower dielectric substrate. The first branch module and the second branch module are quarter open-circuit branches, wherein the first branch module generates a high-frequency zero point, achieving excellent filtering performance in the upper stop band, and the second branch module forms a low-frequency zero point. However, in the patent, the branch module is an open-circuit branch, and the terminal impedance of the open-circuit branch is infinite, which will result in a strong reflected wave, making the debugging of the antenna voltage standing wave ratio extremely difficult, affecting the impedance matching, and the open-circuit branch of the patent is used to form a filtering effect, without harmonic suppression. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a high-gain filtering antenna with high-order mode and harmonic suppression characteristics.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0008] A filtering antenna comprises: an upper dielectric plate 10 and a lower dielectric plate 20 separated by an air gap, a driving patch 30 and a plurality of parasitic patches 40 arranged on the upper dielectric plate 10, wherein the plurality of parasitic patches 40 are arranged around the driving patch 30;

[0009] A feed line 21 and a plurality of short-circuit branches 50 are arranged on the side of the lower dielectric plate 20 facing away from the upper dielectric plate 10, and a coupling gap 22 is etched on the other side.

[0010] The driving patch 30 receives the electric field radiated from the coupling gap 22, and generates coupled common radiation with the parasitic patch 40, generating a radiation zero point at the upper edge of the passband;

[0011] A plurality of short-circuit branches 50 are respectively located at the terminal and both sides of the feed line 21, and generate absorption zeros at the lower edge of the passband, the position of the out-of-band high-order mode and the position of the second harmonic.

[0012] In one embodiment of the present invention, the plurality of short-circuit branches 50 include a first short-circuit branch 51, a second short-circuit branch 52 and a third short-circuit branch 53;

[0013] The first short-circuit branch 51 is connected in series with the end of the feeder 21 ; the second short-circuit branch 52 and the third short-circuit branch 53 are close to the first short-circuit branch 51 , and are respectively located on both sides of the feeder 21 and connected in parallel therewith.

[0014] In one embodiment of the present invention, a ground plane 24 is disposed on the side of the lower dielectric plate 20 opposite to the upper dielectric plate 10 , and the coupling slot 22 is located at the center of the ground plane 24 .

[0015] In one embodiment of the present invention, a plurality of metal pillars 23 are disposed on the lower dielectric plate 20 , and the plurality of short-circuit branches 50 are connected to the ground plane through the plurality of metal pillars 23 .

[0016] In one embodiment of the present invention, the length of the short-circuit branch 50 is ,in, is the medium wavelength.

[0017] In one embodiment of the present invention, four parasitic patches 40 are arranged in a row with every two parasitic patches 40 , respectively taking the driving patch 30 as the symmetry center and located on both sides of the driving patch 30 .

[0018] In one embodiment of the present invention, a rectangular groove 41 is etched on each parasitic patch 40 in the middle of the parasitic patch 40 along a direction perpendicular to the current vector.

[0019] In one embodiment of the present invention, the zero point of the upper edge is controllable by changing the width of the driving patch 30 .

[0020] In one embodiment of the present invention, the zero point of the lower edge is controllable by changing the length of the first short-circuit branch 51 .

[0021] The present invention also provides a 5G communication device, which uses the filtering antenna described above.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: the filtering antenna of the present invention, relative to the existing filtering antenna products, not only achieves high gain and filtering characteristics, but also has high-order mode and harmonic suppression characteristics, and changes the traditional slow wave suppression to absorption suppression, which not only improves the high-frequency suppression, but also greatly simplifies the design difficulty. Compared with the traditional filtering antenna, the present invention has the characteristics of high gain, high suppression, simple structure, and strong universality. The working frequency band of the filtering antenna is 3.26-3.88GHz, the gain peak in the passband is 12.4dBi, the suppression at the high-order mode is 34.6dBc, and the suppression at the second harmonic is 31.3dBc. At the same time, the high-frequency suppression method adopted by the present invention has extremely strong universality. The method proposed by the present invention can be used on other antennas to achieve a similar frequency response.

[0023] The present invention demonstrates that the third-order parallel short-circuit branches achieve out-of-band zero points, high-order mode suppression and harmonic suppression, and verifies the superiority of multi-stage parallel short-circuit branches in high-frequency out-of-band suppression. It also deduces and verifies that if more stages of short-circuit branches are used, that is, multiple second short-circuit branches and third short-circuit branches are respectively located on both sides of the feeder and connected in parallel with them, the suppression characteristics of the third and higher order harmonics can be achieved, which has extremely high universality and ductility. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of a filtering antenna according to an embodiment of the present invention.

[0025] FIG. 2( a ) is an exploded view of a filtering antenna according to an embodiment of the present invention.

[0026] FIG. 2( b ) is a side view of the filtering antenna according to an embodiment of the present invention.

[0027] FIG3( a ) is a schematic diagram of Ant Ⅰ of the evolution process of the filtering antenna according to an embodiment of the present invention.

[0028] FIG3( b ) is a schematic diagram of Ant II showing the evolution process of the filtering antenna according to an embodiment of the present invention.

[0029] FIG3( c ) is a schematic diagram of Ant III showing the evolution process of the filtering antenna according to an embodiment of the present invention.

[0030] FIG3( d ) is a schematic diagram of Ant IV showing the evolution process of the filtering antenna according to an embodiment of the present invention.

[0031] FIG3( e ) is a schematic diagram of Ant V showing the evolution process of the filtering antenna according to an embodiment of the present invention.

[0032] FIG4( a ) is a schematic diagram showing a comparison of S parameters of a filtering antenna at various evolution stages according to an embodiment of the present invention.

[0033] FIG4( b ) is a schematic diagram showing a gain comparison of the filtering antenna at each evolution stage according to an embodiment of the present invention.

[0034] FIG5( a ) is an equivalent circuit diagram of the first short-circuit branch according to an embodiment of the present invention.

[0035] FIG5( b ) is a gain curve of different length values ​​of the first short-circuit branch according to an embodiment of the present invention.

[0036] FIG5( c ) is a gain curve of different capacitance and inductance values ​​in the first short-circuit stub equivalent circuit according to an embodiment of the present invention.

[0037] FIG. 6 ( a ) and FIG. 6 ( b ) are schematic diagrams showing the dimension definition of the filtering antenna according to the embodiment of the present invention.

[0038] FIG. 7( a ) and FIG. 7( b ) are equivalent circuit diagrams of the second short-circuit branch and the third short-circuit branch according to an embodiment of the present invention.

[0039] FIG8( a ) is a gain curve of the second short-circuit branch with different width values ​​according to an embodiment of the present invention.

[0040] FIG8( b ) is a gain curve of different length values ​​of the second short-circuit branch according to an embodiment of the present invention.

[0041] FIG9( a ) is a gain curve of different capacitance and inductance values ​​in the second short-circuit branch equivalent circuit according to an embodiment of the present invention.

[0042] FIG9( b ) is a gain curve of different capacitance and inductance values ​​in the third short-circuit branch equivalent circuit according to an embodiment of the present invention.

[0043] FIG. 10( a ) and FIG. 10( b ) are schematic diagrams showing the distribution of patch current on the upper dielectric plate at 4.23 GHz and 3.27 GHz, respectively, in an embodiment of the present invention.

[0044] Fig.11 1 is a simulation gain curve of different length values ​​of the driving patch according to an embodiment of the present invention.

[0045] FIG. 12( a ) is a schematic diagram of simulated and measured gain and return loss of a filtering antenna according to an embodiment of the present invention.

[0046] FIG. 12( b ) is a schematic diagram of simulated and measured out-of-band suppression of the filtering antenna according to an embodiment of the present invention.

[0047] FIG. 12( c ) is a diagram of the filter antenna according to an embodiment of the present invention simulated and measured in the xoz plane at 3.5 GHz.

[0048] FIG. 12( d ) is a diagram of the filter antenna according to an embodiment of the present invention simulated and measured in the xoz plane at 3.5 GHz. DETAILED DESCRIPTION

[0049] In order to facilitate those skilled in the art to understand the technical solution of the present invention, the technical solution of the present invention is further described in conjunction with the accompanying drawings of the specification.

[0050] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0051] See also Figure 1 As shown in FIG. 2 (b), the present invention provides a filtering antenna, comprising: an upper dielectric plate 10, a lower dielectric plate 20 separated by an air gap, a driving patch 30 and a plurality of parasitic patches 40 arranged on the upper dielectric plate 10, and the plurality of parasitic patches 40 are arranged around the driving patch 30. In addition, a feed line 21 and a plurality of short-circuit branches 50 are arranged on the side of the lower dielectric plate 20 facing away from the upper dielectric plate 10, and a coupling slot 22 is etched on the other side. The driving patch 30 receives the electric field radiated from the coupling slot 22, and generates coupled common radiation at the parasitic patch 40, which can not only increase the gain by increasing the radiation area, but also generate a radiation cancellation effect, and generate a radiation zero point at the upper edge of the passband. The plurality of short-circuit branches 50 are respectively located at the terminal and both sides of the feed line 21, and generate absorption zero points at the lower edge of the passband, the position of the out-of-band high-order mode and the position of the second harmonic, so as to achieve filtering effect and high-order mode and harmonic suppression characteristics, and the zero points at the upper edge and the lower edge are independently controllable.

[0052] In one embodiment of the present invention, a plurality of connection holes are provided on the lower dielectric plate 20 and the upper dielectric plate 10. Nylon screws connect the lower dielectric plate 20 and the upper dielectric plate 10 through the connection holes and keep a certain distance between them so as to separate them with an air gap.

[0053] In this embodiment, a ground plane 24 is provided on the side of the lower dielectric plate 20 relative to the upper dielectric plate 10, and the coupling slot 22 is located at the center of the ground plane 24. A slot antenna is formed on the lower dielectric plate 20, and the upper dielectric plate 10 is fed by slot coupling feeding. It is clear that the coupling slot 22 and the feed line 21 are respectively on the two side surfaces of the lower dielectric plate 20, and in the plane projection direction, the end of the feed line 21 passes through the coupling slot 22, and the driving patch 30 covers the coupling slot 22.

[0054] In this embodiment, a plurality of metal pillars 23 are disposed on the lower dielectric plate 20 , and the plurality of short-circuit branches 50 are connected to the ground plane 24 through the plurality of metal pillars 23 .

[0055] In this embodiment, the plurality of short-circuit branches 50 include a first short-circuit branch 51, a second short-circuit branch 52, and a third short-circuit branch 53. The first short-circuit branch 51 is connected in series with the end of the feeder 21, and the second short-circuit branch 52 and the third short-circuit branch 53 are close to the first short-circuit branch 51, and are respectively located on both sides of the feeder 21 and connected in parallel therewith. Specifically, in the plane projection direction, the first short-circuit branch 51 is located on one side of the coupling slot 22, and the second short-circuit branch 52 and the third short-circuit branch 53 are located on the other side of the coupling slot 22.

[0056] In this embodiment, the driving patch 30 and the plurality of parasitic patches 40 are located on the top of the upper dielectric plate 10, and four parasitic patches 40 are arranged in a row of two parasitic patches 40, respectively, with the driving patch 30 as the symmetry center, and are located on both sides of the driving patch 30. A rectangular groove 41 is etched on each parasitic patch 40 along a direction perpendicular to the current vector.

[0057] Please refer to FIG. 3 (a) to FIG. 3 (e). The evolution process of the filtering antenna of the present invention is described below. The design concept and working mechanism of the filtering antenna are elaborated in detail by showing the evolution process of the filtering antenna structure and its corresponding electrical performance.

[0058] The design concept of the filtering antenna starts from a simple slot-coupled microstrip antenna. A coupling slot 22 is etched on the ground plane 24 on the side of the lower dielectric plate 20 opposite to the upper dielectric plate 10, and a feed line 21 is set on the other side to form a slot antenna. A driving patch 30 is set on the top of the upper dielectric plate 10, that is, on the side facing away from the lower dielectric plate 20, and the driving patch 30 is fed by a slot antenna, as shown in Figure 3 (a).

[0059] Please refer to Figure 3 (a) and (b), in Ant II, the feeder 21 terminal of Ant I is connected in series with a The first short-circuit branch 51 is shown in Figures 4 (a) and (b) for comparison of the simulation results of Ant I and Ant II. The resonant frequency position of the curve is the same, indicating that the position of the resonant point is not affected by the first short-circuit branch 51, and the terminal of the feed line 21 changes from open circuit to short circuit, and the impedance changes from infinity to zero, which makes it easier to achieve impedance matching. At the same time, a radiation zero point is generated at the low end of the antenna passband, so the antenna evolves from Ant I to Ant II. Among them, S11 is one of the S parameters, which represents the return loss characteristic. And, Expressed as the medium wavelength.

[0060] Please refer to Figures 3 (c) and (d). In order to generate a radiation zero point above the passband of the filtering antenna, four parasitic patches 40 are placed around the driving patch 30. Through capacitive coupling, a radiation zero point is generated above the passband of the filtering antenna. As can be seen from Figure 4 (b), the filtering antenna has a concave point at a frequency of 3.27 GHz in the passband. After a rectangular groove 41 is etched in the middle of each of the four parasitic patches 40, the concave point in the middle of the passband disappears, and the antenna evolves into Ant IV.

[0061] Please refer to Figure 3 (c) to Figure 3 (e). Whether it is Ant III or Ant IV, the suppression near the harmonics and high-order modes in the out-of-band high-frequency direction is very poor, especially the gain anti-warping is high at the resonance point. Therefore, two short-circuit branches are introduced near the terminal of the feed line 21, namely the second short-circuit branch 52 and the third short-circuit branch 53, which effectively suppresses the high-order mode radiation and second harmonic radiation of the filter antenna. The filter antenna evolves into Ant V, and the performance is shown in Figure 4 (b).

[0062] See also Figure 1 As shown in FIG9(b), in one embodiment of the present invention, the working mechanism of the filtering antenna is described below. The lower edge zero point analysis is as follows: In order to improve the rectangular coefficient of the antenna, a feeder 21 terminal is added. The first short-circuit branch 51 can produce an absorption zero at 2.79 GHz, which is located at the lower edge of the passband, achieving a suppression level of 33.9 dBc. The equivalent circuit of the short-circuit branch is shown in Figure 5 (a). The first short-circuit branch 51 can be regarded as a grounded series LC resonator. When the resonator resonates at a certain frequency, it can absorb the signal energy of the antenna at this point, so that the signal of the antenna at this point cannot be transmitted normally, realizing the transmission zero effect. By adjusting the length of the first short-circuit branch 51, the capacitance and inductance values ​​of the equivalent resonator can be changed, so that the resonant frequency of the resonator changes, and the position of the transmission zero changes. Figure 5 (b) shows the length of the first short-circuit branch 51. The curve of the transmission zero point changes with the change of the transmission zero point. It can be seen that when the length of the first short-circuit branch 51 increases, its corresponding equivalent inductance and capacitance values ​​increase, and the resonant frequency decreases, and the zero point moves toward the low frequency direction. The zero point change curve when the capacitance and inductance of the resonator change is given in Figure 5 (c), which verifies the correctness of the theoretical analysis. Table 1 gives the equivalent inductance and capacitance values ​​of the equivalent circuit of the first short-circuit branch 51 at different zero points, as well as the definition of the filter antenna size, see Figures 6 (a) and 6 (b).

[0063] Table 1 Capacitor and inductor parameters of short-circuit branch equivalent circuits with different zero points

[0064]

[0065] The high-order mode and harmonic suppression analysis is as follows: In Figure 4 (a), Ant IV It can be seen that a resonance point appears at 4.83 GHz above the passband of the antenna, which is the high-order mode of the antenna. At the same time, there is also a relatively gentle high-frequency resonance point at 7.79 GHz, which is the second harmonic of the antenna. It can be clearly seen from Figure 4 (b) that the gain of the antenna shows a significant upward trend at these two frequencies. In order to achieve the suppression of the antenna at 4.83 GHz and 7.79 GHz, two short-circuit branches are connected in parallel near the terminal of the feeder 21, namely the second short-circuit branch 52 and the third short-circuit branch 53, as shown in Figure 3 (e). The length of the second short-circuit branch 52 and the third short-circuit branch 53 is set to a quarter wavelength of the corresponding frequency point to suppress the signal transmission of the antenna at these two points. The equivalent circuits of the second short-circuit branch 52 and the third short-circuit branch 53 are shown in FIG7 (a) and (b). According to the equivalent principle of the first short-circuit branch 51, the resonant frequency can be changed by simply changing the capacitance and inductance. For a microstrip line, the equivalent capacitance and inductance can be changed by changing the line length or line width. In FIG8 (a) and (b), it can be observed that the width of the third short-circuit branch 53 is and the length of the second short-circuit branch 52 The influence of the change on the suppression degree is also studied. At the same time, the equivalent circuit is simulated. The curves of the suppression zero frequency changing with the change of the capacitance and inductance parameters in the equivalent circuit are given in Figure 9 (a) and (b), which verifies the effectiveness of this method in suppressing high-order modes and second harmonics.

[0066] Table 1 shows the equivalent inductance and capacitance of the equivalent circuit of the second short-circuit branch 52 and the third short-circuit branch 53 at different zero points. It should be noted that the three short-circuit branches are parasitic on the feeder 21, which will have a certain impact on the antenna standing wave ratio. Due to the factors, a compromise needs to be considered when selecting the zero point related parameter values.

[0067] The upper edge zero point analysis is as follows: In order to explain in detail the formation principle of the upper edge zero point and the cause of the passband notch in Ant III, the current distribution of the driving patch 30 and the four parasitic patches 40 at 4.23 GHz and 3.27 GHz are shown in Figures 10 (a) and (b). First of all, it can be clearly seen in Figure 10 (a) that at 4.23 GHz, except for the two ends of the antenna, the current distribution at other points on the driving patch 30 is relatively even, and the direction of the current vector is consistent and maintains a strong state. The currents of the four parasitic patches 40 are mainly concentrated on the inside and outside, and the direction of the current vector is opposite to that of the current vector of the driving patch 30. At this time, the radiation at 4.23 GHz is canceled, and the antenna produces an absorption zero at this point. Based on this principle, it can be inferred that the position of the zero point is mainly related to the size of the driving patch. Fig.11 The simulation results of different widths L2 of the driving patch 30 are shown in FIG5 . It can be seen that as the width L2 of the driving patch 30 increases, the radiation zero frequency of the upper edge gradually moves toward the low frequency direction, verifying the accuracy of the assumption. Fig.11 By comparison, it is found that the two zero points at the edge of the passband are independently controllable, which reflects the superiority of this design method. Figure 10 (b) shows the current distribution of the antenna at 3.27GHz. The current distribution at this frequency is in the middle and on both sides of the driving patch 30 and the parasitic patch 40. By observing the current distribution, it can be seen that the current distribution and amplitude of the four axisymmetric parasitic patches 40 are basically the same, but the current vector directions are opposite, so the electric field cancels each other, resulting in a concave point in the passband. In Ant V, a rectangular groove 41 is etched in the middle of the parasitic patch 40 along the direction perpendicular to the current vector to cut off the current. In Figure 4 (b), it can be seen that the concave point in the passband disappears, that is, by loading the parasitic patch 40 around the driving patch 30, the radiation area is increased, the gain is improved, and a filtering effect is produced.

[0068] In one embodiment of the present invention, simulation is used to verify the accuracy of the filtering antenna, as shown in Figures 12(a) to (d). As can be seen from Figure 12(a), the antenna It is less than -10dB in the passband of 3.26-3.88GHz, indicating that the antenna has good traveling wave characteristics. From the gain curve, it can be seen that the gain of the filtering antenna in the passband reaches up to 12.4GHz, showing good high-gain characteristics. Figure 12 (b) In the high-frequency direction outside the passband, the high-order mode reaches 34.6dBc and the harmonic suppression reaches 31.3dBc. Both the simulation results and the test results show good high-order mode and harmonic suppression characteristics. It should be noted here that due to the existence of multi-stage short-circuit branches, while improving the filtering and suppression characteristics, multiple zero points are introduced in the high-frequency direction outside the passband, which greatly improves the high-frequency suppression effect. Figures 12 (c) and (d) show the simulated and measured radiation patterns of the antenna at 3.5GHz. The figure shows that the simulation and test radiation patterns are basically consistent, both maintaining good directivity and having very low cross-polarization.

[0069] It can be seen from the above that the filtering antenna of the present invention operates in the Sub-6G frequency band. Therefore, in another embodiment of the present invention, the present invention also provides a 5G communication device, which uses the filtering antenna described above.

[0070] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-limiting from any point of view, and the scope of the present invention is defined by the appended 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, and any reference numerals in the claims should not be regarded as limiting the claims involved.

[0071] The embodiments described above only represent implementation methods of the invention. The protection scope of the present invention is not limited to the embodiments described above. For those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A filtering antenna, characterized in that: include: An upper dielectric plate (10), a lower dielectric plate (20), a driving patch (30) and a plurality of parasitic patches (40) arranged on the upper dielectric plate (10) separated by an air gap, wherein the plurality of parasitic patches (40) are arranged around the driving patch (30); A feeder line (21) and a plurality of short-circuit branches (50) are arranged on the side of the lower dielectric plate (20) facing away from the upper dielectric plate (10), and a coupling gap (22) is etched on the other side. The driving patch (30) receives the electric field radiated from the coupling gap (22), and generates coupled common radiation with the parasitic patch (40), thereby generating a radiation zero point at the upper edge of the passband; A plurality of short-circuit branches (50) are respectively located at the terminal and both sides of the feed line (21), and generate absorption zero points at the lower edge of the passband, the position of the out-of-band high-order mode, and the position of the second harmonic.

2. The filtering antenna according to claim 1, characterized in that: The plurality of short-circuit branches (50) include a first short-circuit branch (51), a second short-circuit branch (52) and a third short-circuit branch (53); The first short-circuit branch (51) is connected in series with the end of the feeder (21); the second short-circuit branch (52) and the third short-circuit branch (53) are close to the first short-circuit branch (51), and are respectively located on both sides of the feeder (21) and connected in parallel thereto.

3. The filtering antenna according to claim 2, characterized in that: A ground plane (24) is provided on the side of the lower dielectric plate (20) opposite to the upper dielectric plate (10), and the coupling gap (22) is located at the center of the ground plane (24).

4. The filtering antenna according to claim 3, characterized in that: A plurality of metal columns (23) are arranged on the lower dielectric plate (20), and a plurality of short-circuit branches (50) are connected to a ground plane (24) via the plurality of metal columns (23).

5. The filtering antenna according to claim 2, characterized in that: The length of the short-circuit branch (50) is ,in, is the medium wavelength.

6. The filtering antenna according to claim 1, characterized in that: The four parasitic patches (40) are arranged in a row with two parasitic patches (40) each, with the driving patch (30) as the symmetry center, and are located on both sides of the driving patch (30).

7. The filtering antenna according to claim 6, characterized in that: In the middle of the parasitic patch (40), a rectangular groove (41) is etched on each parasitic patch (40) along a direction perpendicular to the current vector.

8. The filtering antenna according to claim 1, characterized in that: By changing the width of the driving patch (30), the zero point of the upper edge can be controlled.

9. The filtering antenna according to claim 2, characterized in that: By changing the length of the first short-circuit branch (51), the zero point of the lower edge can be controlled.

10. A 5G communication device, characterized in that: A filtering antenna as described in any one of claims 1 to 9 is used.

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