A low profile diplex filter antenna

Abstract

The application provides a low-profile duplex filter antenna and belongs to the technical field of wireless energy transmission.The low-profile duplex filter antenna comprises an upper metal floor, a dielectric substrate, a lower metal floor, a cavity column, a perturbation via and a suppression via; the lower metal floor is arranged on the lower surface of the lower dielectric substrate; the upper metal floor is arranged on the upper surface of the dielectric substrate; the cavity column penetrates through the upper metal floor, the dielectric substrate and the lower metal floor and surrounds a substrate integrated waveguide cavity; the perturbation via and the suppression via penetrate through the upper metal floor, the dielectric substrate and the lower metal floor; a cross-shaped groove is etched in the center of the upper metal floor; two complementary split ring resonator grooves with different diameters are etched at the connection between the circular cavity and the two side rectangular cavities of the upper metal floor; two feed lines are led out from the two ends of the upper metal floor. The antenna has the characteristics of low profile, is easy to integrate, and simultaneously reduces the manufacturing cost of the antenna and facilitates processing and manufacturing.

Description

Technical Field

[0001] This invention belongs to the field of wireless power transmission technology and relates to a low-profile duplex filter antenna. Background Technology

[0002] Modern wireless communication technology is rapidly evolving towards 6G, characterized by significantly increased data rates and increasingly scarce spectrum resources, while simultaneously demanding highly miniaturized, low-profile antennas. This trend places unprecedented demands on radio frequency (RF) front-end modules. In recent years, substrate integrated waveguides (SIWs) have been widely used in antenna design due to their low loss, ease of miniaturization, and low-profile structure.

[0003] A duplexer enables the transmitter and receiver to use the same antenna; in traditional RF front-ends, this device is typically a separate component. A duplex antenna integrates the duplex function with the antenna, solving the problems associated with separate components, reducing circuit size, and avoiding additional transmission line losses. Meanwhile, to achieve device miniaturization and improve interference immunity, filtering antenna technology has been introduced into duplex antenna design. Low-profile duplex filtering antennas, with their compact integration and low loss characteristics, have further driven the miniaturization of RF front-ends. However, developing a duplex filtering antenna that combines widened impedance bandwidth and low-profile characteristics while maintaining good in-band radiation performance and out-of-band filtering response remains a technical challenge. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a low-profile duplex filter antenna that can achieve a large axial ratio bandwidth and has excellent in-band radiation performance and out-of-band filtering response; the antenna has the characteristics of low profile, is easy to integrate, and at the same time reduces the manufacturing cost of the antenna and is easy to process and manufacture.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A low-profile duplex filter antenna includes an upper metal ground plane, a dielectric substrate, a lower metal ground plane, cavity pillars, disturbance vias, and suppression vias. The lower metal ground plane is disposed on the lower surface of the lower dielectric substrate. The upper metal ground plane is disposed on the upper surface of the dielectric substrate. Multiple cavity pillars penetrate the upper metal ground plane, the dielectric substrate, and the lower metal ground plane, forming a substrate integrated waveguide (SIW) cavity. The multiple disturbance vias and multiple suppression vias penetrate the upper metal ground plane, the dielectric substrate, and the lower metal ground plane. A cross-shaped groove is etched at the center of the upper metal ground plane. Two complementary open-ring resonator (CSRR) slots of different diameters are etched at the connection points of different regions of the substrate integrated waveguide cavity on the upper metal ground plane. Two feed lines extend from both ends of the upper metal ground plane.

[0006] Furthermore, the substrate integrated waveguide cavity includes a circular cavity and two rectangular cavities; the circular cavity is connected to two rectangular cavities of different sizes on both sides; the first rectangular cavity is longer and narrower than the second rectangular cavity.

[0007] Furthermore, there are a total of 4 disturbance vias, which penetrate the upper metal ground plane, the dielectric substrate, and the lower metal ground plane respectively; there are a total of 8 suppression vias, which penetrate the upper metal ground plane, the dielectric substrate, and the lower metal ground plane respectively.

[0008] Furthermore, the cross-shaped groove includes a vertical groove and two horizontal grooves; the two horizontal grooves are of different sizes and are respectively disposed on opposite sides of the vertical groove.

[0009] Furthermore, the two horizontal grooves include a first horizontal groove and a second horizontal groove; the length and width of the first horizontal groove are both smaller than the length and width of the second horizontal groove.

[0010] Furthermore, the two complementary open-ring resonator slots include a first complementary open-ring resonator slot and a second complementary open-ring resonator slot; the first complementary open-ring resonator slot is etched at the connection between the circular cavity and the first rectangular cavity, and the second complementary open-ring resonator slot is etched at the connection between the circular cavity and the second rectangular cavity; the diameter of the first complementary open-ring resonator slot is smaller than the diameter of the second complementary open-ring resonator slot.

[0011] Furthermore, the antenna has a profile height of 0.02λ0, where λ0 is the free space wavelength corresponding to the center frequency; the antenna has two operating frequency bands of 3.87 GHz to 4.12 GHz and 4.84 GHz to 5.16 GHz, with in-band gains of 4.3 dBi and 5.12 dBi, respectively, and the isolation between the two ports is greater than 18 dB.

[0012] The beneficial effects of this invention are as follows: 1) A cross-shaped groove is etched on the top of the circular SIW cavity to form four quarter-mode substrate integrated waveguide (QMSIW) cavities as radiating units. Perturbation vias are added inside the cavities to tune the operating frequency. Furthermore, suppression vias are arranged in a specific pattern around the cross-shaped grooves to suppress cross-polarization. Rectangular SIW feed cavities with etched CSRR grooves are connected to both sides of the circular cavity to excite the QMSIW resonator, achieving good radiation and filtering performance.

[0013] 2) The antenna's -10 dB relative impedance bandwidth ranges from 3.87 GHz to 4.12 GHz in the low-frequency passband and from 4.84 GHz to 5.16 GHz in the high-frequency passband. The realized gains in the low-frequency and high-frequency passbands are 4.3 dBi and 5.12 dBi, respectively. The port isolation is greater than 18 dB.

[0014] 3) It achieves high bandwidth while maintaining a low profile, with a profile height of 0.02λ0. Compared to previously proposed SIW duplex antennas, the bandwidth improvement is significant, and it also has good filtering performance, making it valuable for engineering applications. Attached Figure Description

[0015] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the low-profile duplex filter antenna structure described in this invention; Figure 2 This is a schematic diagram of the dimensions of the low-profile duplex filter antenna described in this invention; Figure 3 The low-profile duplex filter antenna described in this invention S parameter; Figure 4 The low-profile duplex filter antenna described in this invention can achieve increased gain; Figure 5 The radiation pattern of the low-profile duplex filter antenna described in this invention is shown at the center frequency; where (a) is 4 GHz and (b) is 5 GHz. Reference numerals: 1. Upper metal ground plane, 2. Dielectric substrate, 3. Lower metal ground plane, 4. Cavity pillar, 5. Disturbance via, 6. Suppression via, 7. Vertical slot, 8. Horizontal slot, 9. CSRR slot, 10. Feeder. Detailed Implementation

[0016] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0017] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0018] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0019] See appendix Figure 1 This invention provides a low-profile duplex filter antenna, comprising an upper metal ground plane 1, a dielectric substrate 2, a lower metal ground plane 3, a cavity pillar 4, a disturbance via 5, a suppression via 6, a vertical slot 7, a horizontal slot 8, a CSRR slot 9, and a feed line 10. The lower metal ground plane 3 is disposed on the lower surface of the dielectric substrate 2, and the upper metal ground plane 1 is disposed on the upper surface. The cavity pillar 4 penetrates the upper metal ground plane 1, the dielectric substrate 2, and the lower metal ground plane 3. The disturbance via 5 and the suppression via 6 penetrate the upper metal ground plane 1, the dielectric substrate 2, and the lower metal ground plane 3. The vertical slot 7 and the horizontal slot 8 are etched on the upper metal ground plane 1. The CSRR slot 9 is etched on the upper metal ground plane 1. Feed lines 10 are disposed at both ends of the upper metal ground plane 1.

[0020] The lower metal ground plane is the same size as the dielectric substrate, both with a length of 112.5 mm and a width of 62 mm. The vertical slots are 57.6 mm long and 8.5 mm wide, the long horizontal slots are 19.9 mm long and 1.9 mm wide, and the short horizontal slots are 10.6 mm long and 1.5 mm wide. The four disturbance vias have a diameter of 1 mm. The four suppression vias have a diameter of 1 mm. The cavity pillars have a diameter of 1.3 mm. The inner radius of the first CSRR slot is 2.1 mm, and the inner radius of the second CSRR slot is 2.3 mm.

[0021] The dielectric substrate was made of Arlon AD255C (tm), with a relative permittivity of 2.55 and a loss tangent of 0.0014.

[0022] The low-profile duplex filter antenna was simulated using the high-frequency electromagnetic simulation software HFSS2022. The parameters after simulation optimization are shown in Table 1 (unit: mm).

[0023] Table 1

[0024] See attached document Figure 2 , W The width of the metal ground plane and the dielectric substrate. w 1- w 2 represents the width of the feeder. w 3- w 4 represents the width of the short horizontal groove and the long horizontal groove, respectively. w 5- w 6 represents the width of the first rectangular cavity and the second rectangular cavity, respectively. L The lengths of the metal ground plane and the dielectric substrate are given. l 1- l 4 represents the distance between the disturbance via and the vertical slot. l 5- l 6. To suppress the gap between the via and the vertical slot, l 7- l 8 represents the lengths of the first rectangular cavity and the second rectangular cavity, respectively. l 9- l 10 These are the lengths of the short and long horizontal slots, respectively. R The radius of the circular SIW cavity. R 1- R 2 represents the inner radius of the first CSRR groove and the second CSRR groove, respectively. p 1- p 2 represents the spacing between the rectangular SIW cavity pillars and the circular SIW cavity pillars, respectively. d 1 represents the diameter of the cavity column. d 2 represents the diameter of the disturbing via and the suppressing via. H The thickness of the dielectric substrate.

[0025] Figure 3 This is a graph showing the S-parameters as a function of frequency obtained from the simulation of this invention. As shown in the figure, the simulation results indicate that the -10 dB relative impedance bandwidth range is 3.87 GHz to 4.12 GHz for low-frequency passband and 4.84 GHz to 5.16 GHz for high-frequency passband. The port isolation is greater than 18 dB. Figure 4 This is a simulation curve showing the achievable gain as a function of frequency obtained according to the present invention. The simulated achievable gain curves show that the achievable gains in the low-frequency and high-frequency passbands are 4.3 dBi and 5.12 dBi, respectively, and exhibit good filtering performance. Figure 5Figures (a) and (b) show the simulated radiation patterns of the present invention at 4 GHz and 5 GHz. The simulation results show that the antenna has good wide-side radiation characteristics.

[0026] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A low-profile duplex filter antenna, characterized in that, The antenna includes an upper metal ground plane, a dielectric substrate, a lower metal ground plane, cavity pillars, disturbance vias, and suppression vias; the lower metal ground plane is disposed on the lower surface of the lower dielectric substrate; the upper metal ground plane is disposed on the upper surface of the dielectric substrate. The cavity pillars are multiple, penetrating the upper metal ground plane, the dielectric substrate, and the lower metal ground plane, forming a substrate integrated waveguide cavity; the multiple disturbance vias and multiple suppression vias penetrate the upper metal ground plane, the dielectric substrate, and the lower metal ground plane; a cross-shaped groove is etched in the center of the upper metal ground plane; two complementary open-ring resonator slots of different diameters are etched in the upper metal ground plane at the connection points of different regions of the substrate integrated waveguide cavity; two feed lines are led out from both ends of the upper metal ground plane.

2. The low-profile duplex filter antenna according to claim 1, characterized in that, The substrate integrated waveguide cavity includes a circular cavity and two rectangular cavities; the circular cavity is connected to two rectangular cavities of different sizes on both sides; the first rectangular cavity is longer and narrower than the second rectangular cavity.

3. A low-profile duplex filter antenna according to claim 2, characterized in that, There are four disturbance vias, which penetrate the upper metal ground plane, the dielectric substrate, and the lower metal ground plane respectively; there are eight suppression vias, which penetrate the upper metal ground plane, the dielectric substrate, and the lower metal ground plane respectively.

4. A low-profile duplex filter antenna according to claim 3, characterized in that, The cross-shaped groove includes a vertical groove and two horizontal grooves; the two horizontal grooves are of different sizes and are respectively located on opposite sides of the vertical groove.

5. A low-profile duplex filter antenna according to claim 4, characterized in that, The two horizontal grooves include a first horizontal groove and a second horizontal groove; the length and width of the first horizontal groove are both smaller than the length and width of the second horizontal groove.

6. A low-profile duplex filter antenna according to claim 5, characterized in that, The two complementary open-ring resonator slots include a first complementary open-ring resonator slot and a second complementary open-ring resonator slot; the first complementary open-ring resonator slot is etched at the connection between the circular cavity and the first rectangular cavity, and the second complementary open-ring resonator slot is etched at the connection between the circular cavity and the second rectangular cavity; the diameter of the first complementary open-ring resonator slot is smaller than the diameter of the second complementary open-ring resonator slot.

7. A low-profile duplex filter antenna according to claim 6, characterized in that, The antenna has a profile height of 0.02λ0, where λ0 is the free space wavelength corresponding to the center frequency; the antenna has two operating frequency bands of 3.87 GHz to 4.12 GHz and 4.84 GHz to 5.16 GHz, with in-band gains of 4.3 dBi and 5.12 dBi, respectively, and the isolation between the two ports is greater than 18 dB.

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