Miniaturized substrate integrated waveguide flat top emitting antenna

Abstract

The invention discloses a miniaturized substrate integrated waveguide flat top radiating antenna, and belongs to the field of microwave communication. The antenna comprises a top-layer metal structure, an upper-layer dielectric substrate, a metal ground, a lower-layer dielectric substrate, a bottom-layer metal structure and a metal via hole group, wherein the metal structures are matched with the metal via hole group to form a main resonator, an auxiliary resonator and a planar integratable feed structure. The main resonator consists of a U-shaped metal patch, a rectangular metal patch and a plurality of groups of metal through holes, and a strong vertical electric field is generated in the main resonator; the auxiliary resonator is a double-open fundamental mode resonator and is located in front of the main resonator, and weak vertical reverse electric fields are generated on the two sides of an opening of the auxiliary resonator. The two electric fields are superposed to form flat-top radiation, and the coplanar waveguide feed probe realizes planar integrated feed. The antenna has the characteristics of miniaturization, high integration level, flat-top radiation and gain improvement, and is suitable for scenes of point-to-point communication, radar sensing and the like.

Description

Technical Field

[0001] This invention relates to the field of microwave communication, and more particularly to a substrate integrated waveguide flat-top-emitting antenna. Background Technology

[0002] Substrate-integrated waveguide (SIWB) end-fire antennas achieve performance similar to traditional waveguides with a planar integrable structure, combining low loss, high power capacity, and ease of integration with planar circuits. They can highly concentrate radiated energy along their axial direction, exhibiting high directivity, and can be applied to wireless communication scenarios such as point-to-point communication, radar sensing, and tunnel coverage. Furthermore, SIWB end-fire antennas can generate a uniformly distributed radiation pattern within a specific angular range, achieving stable signal strength within the coverage area. This effectively solves the problem of rapid signal attenuation when deviating from the beam center in traditional conical beams, improving the reliability of communication links over wide beam ranges and enhancing user experience. Simultaneously, miniaturization technology can reduce the size of SIWB end-fire antennas, increase integration density, and lower antenna costs. Therefore, miniaturized SIWB end-fire antennas have significant research and engineering value.

[0003] There are two main reported design methods for substrate-integrated waveguide flat-top horn antennas. The first method involves embedding multiple rows of metal vias within the planar horn antenna to adjust the amplitude and phase distribution of the horn's emitting surface, resulting in a five-half-wave distribution. This achieves flat-top radiation for the substrate-integrated waveguide H-planar horn antenna, but suffers from issues such as large size, small bandwidth, and difficulty in integrating coaxial feed. The second method involves simultaneously exciting a TE in the planar horn antenna. 10 and TE 1 / 2,0 The design utilizes metal strips and vias to construct sequentially out-of-phase fifth-order modes, generating a flat-top radiation effect through their superposition. However, this design also suffers from large size and difficulty in integration. Therefore, it is necessary to propose a miniaturized substrate-integrated waveguide flat-top-firing antenna that can also accommodate planar integrable feeding. Summary of the Invention

[0004] Purpose of the invention: In view of the above-mentioned prior art, a miniaturized substrate integrated waveguide flat-top radiating antenna is proposed, which achieves flat-top radiation while having the characteristics of small size and easy integration.

[0005] Technical solution: A miniaturized substrate-integrated waveguide flat-top-firing antenna, comprising: At least one dielectric substrate, a metal ground, a metal structure layer disposed on the dielectric substrate, and a group of metal vias penetrating the dielectric substrate and the metal ground; The metal structure layer is formed in conjunction with the metal via group and the dielectric substrate: The main resonator is capable of generating a strong vertical electric field and has an opening for signal coupling. The main resonator includes a top metal patch, a bottom metal patch, and a first metal via subgroup. An auxiliary resonator is located in front of the radiation of the main resonator. It can generate a weak vertical electric field opposite to the strong vertical electric field on both sides of the opening of the main resonator. The weak vertical electric field and the strong vertical electric field are superimposed to form a flat-top radiation on a horizontal plane. The auxiliary resonator includes a top auxiliary metal strip, a bottom auxiliary metal strip, and a second metal via subgroup. A planar integrable power supply structure is provided, which can couple external signals to the main resonator and excite it to generate a strong vertical electric field, and is coplanarly integrated with the metal structure layer and the dielectric substrate.

[0006] Furthermore, the top metal patch is a U-shaped metal patch, and the bottom metal patch is a rectangular metal patch, with the two aligned vertically; the U-shaped metal patch has a notch, and the first metal via subgroup includes metal via one, metal via two, and metal via five. Metal via one and metal via two connect the U-shaped metal patch and the rectangular metal patch, and surround each other to form a resonant space that can constrain a strong vertical electric field.

[0007] Furthermore, the first metal via is arranged laterally on the top of the two arms of the U-shaped metal patch, and the second metal via is arranged vertically on the outer side of the two arms of the U-shaped metal patch, forming two opposing L-shaped structures that pass vertically through the metal ground and the dielectric substrate.

[0008] Furthermore, the top auxiliary metal strip is metal strip three, and the bottom auxiliary metal strip is metal strip four, which are aligned vertically; the second metal via subgroup is metal via three, which are arranged vertically at both ends of metal strip three, passing vertically through the metal ground and the dielectric substrate, and connecting metal strip three and metal strip four; the auxiliary resonator has no closed cavity and is in a double-sided open form.

[0009] Furthermore, the planar integrable feed structure includes a feed transmission line and a feed probe. The feed transmission line is a feed microstrip line, composed of a metal strip, a dielectric substrate, and a metal ground. The feed probe is embedded in the U-shaped metal patch notch of the main resonator, and excites the main resonator through both coupling and signal transmission.

[0010] Furthermore, the feed probe is a coplanar waveguide feed probe, comprising a second metal strip and a fourth metal via. The second metal strip is coupled to a U-shaped metal patch, and the fourth metal via is located at the front end of the second metal strip, perpendicularly passing through the dielectric substrate to connect the second metal strip and the rectangular metal patch.

[0011] Furthermore, the dielectric substrate includes an upper dielectric substrate and a lower dielectric substrate, with the metal ground sandwiched between the upper dielectric substrate and the lower dielectric substrate; the metal structure layer includes a top metal structure and a bottom metal structure, which are respectively disposed on the upper surface of the upper dielectric substrate and the lower surface of the lower dielectric substrate.

[0012] Furthermore, the vertical dimension of the main resonator is 0.29λ0~0.33λ0, the horizontal dimension is between 0.29λ0~0.33λ0, and the width of the notch is between 0.11λ0~0.14λ0, where λ0 is the free space wavelength corresponding to the center frequency.

[0013] Furthermore, the horizontal length of the metal strip three of the auxiliary resonator is 0.06λ0~0.10λ0, and the vertical width is 0.30λ0~0.34λ0.

[0014] Furthermore, the length of the second metal strip of the feed probe is 0.15λ0~0.20λ0.

[0015] Beneficial Effects: Existing substrate integrated waveguide flat-top radiating antennas struggle to achieve both flat-top radiation and small antenna size, and most are coaxially fed, making integration difficult. Some designs also suffer from limited bandwidth. This invention utilizes a coplanar waveguide-fed probe to excite a fundamental mode substrate integrated waveguide resonator, combined with a front-end dual-open fundamental mode resonator. This creates a relatively weak vertical reverse electric field on both sides of the opening of the fundamental mode substrate integrated waveguide resonator. By superimposing the weak reverse electric field with the strong internal electric field, a miniaturized flat-top radiation effect of the substrate integrated waveguide is achieved, along with the characteristic of planar integrable feeding.

[0016] Specifically, the fundamental mode substrate integrated waveguide resonator consists of a U-shaped metal patch, a rectangular metal patch, and multiple sets of metal vias. It exhibits a strong vertical electric field distribution internally, and with the assistance of a front-mounted dual-open fundamental mode resonator, weak reverse electric fields are formed on both sides. This resonator is excited by a coplanar waveguide feed probe embedded within a U-shaped notch. The probe's strips couple the signal to the upper layer, while the probe's vias transmit the signal to the lower layer, thus achieving an easily integrated planar feed method.

[0017] The dual-open fundamental mode resonator consists of a top metal strip (3), a bottom metal strip (4), and a metal via (3) connecting the two, located in front of the fundamental mode substrate integrated waveguide resonator. Its function is to assist the fundamental mode substrate integrated waveguide resonator in generating weak vertical reverse electric fields on both sides of the opening. These fields, when superimposed with the internal electric field, form a flat-top radiation on a horizontal plane, thereby improving the overall antenna gain. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the layer structure of the miniaturized substrate integrated waveguide flat-top-fire antenna of the present invention; Figure 2 This is a three-dimensional structural schematic diagram of the miniaturized substrate integrated waveguide flat-top-fire antenna of the present invention; Figure 3 The simulated impedance matching curve of the antenna of this invention is shown. Figure 4 This is the horizontal radiation pattern of the antenna of the present invention at the center frequency (23.52GHz).

[0019] Figure label: 1-Top layer metal structure, 2-Upper dielectric substrate, 3-Metal ground, 4-Lower dielectric substrate, 5-Bottom layer metal structure, 6-Metal via group; 101-Metal strip one, 102-Metal strip two, 103-U-shaped metal patch, 104-Metal strip three, 501-Rectangular metal patch, 502-Metal strip four, 601-Metal via one, 602-Metal via two, 603-Metal via three, 604-Metal via four, 605-Metal via five. Detailed Implementation

[0020] The invention will now be further explained with reference to the accompanying drawings.

[0021] like Figure 1 , Figure 2 As shown, a miniaturized substrate integrated waveguide flat-top antenna includes a top metal structure 1, an upper dielectric substrate 2, a metal ground 3, a lower dielectric substrate 4, a bottom metal structure 5, and a group of metal vias 6.

[0022] The top metal structure 1 consists of metal strip 101, metal strip 2 102, U-shaped metal patch 103, and metal strip 3 104. Metal strip 101 and metal strip 2 102 are connected in a straight line. Metal strip 2 102 is embedded in the notch of U-shaped metal patch 103. Metal strip 3 104 is located in front of U-shaped metal patch 103 and is parallel to the bottom of U-shaped metal patch 103.

[0023] Among them, the length of metal strip 102 is between 0.15λ0 and 0.20λ0, where λ0 is the free space wavelength corresponding to the center frequency; the length of U-shaped metal patch 103 is between 0.29λ0 and 0.33λ0, the width is between 0.29λ0 and 0.33λ0, and the width of the notch is between 0.11λ0 and 0.14λ0; the length of metal strip 104 is between 0.06λ0 and 0.10λ0, and the width is between 0.30λ0 and 0.34λ0.

[0024] The bottom metal structure 5 consists of a rectangular metal patch 501 and a metal strip 502. The metal strip 502 is located in front of and parallel to the rectangular metal patch 501. Both are aligned vertically with the U-shaped metal patch 103 and the metal strip 104, respectively, and have the same outer contour size.

[0025] The metal via group 6 consists of metal via 601, metal via 602, metal via 603, metal via 604, and metal via 605. Two rows of metal vias 601 are arranged horizontally (y-direction) on the top of the two arms of the U-shaped metal patch 103, and two rows of metal vias 602 are arranged vertically (x-direction) on the outer sides of the two arms of the U-shaped metal patch 103. The two rows of metal vias 601 and 602 form two opposing L-shaped structures, which vertically pass through the metal ground 3 and the upper and lower dielectric substrates 2 and 3, connecting the top U-shaped metal patch 103 and the bottom rectangular metal patch 501. Two rows of metal vias 603 are arranged vertically (x-direction) at both ends of metal strip 104, passing vertically through ground plane 3 and upper and lower dielectric substrates 2 and 3, connecting metal strip 104 and metal strip 502. A row of metal vias 605 is arranged horizontally (y-direction) at the edge of rectangular metal patch 501 opposite the notch of U-shaped metal patch 103, passing vertically through lower dielectric substrate 4 and connecting rectangular metal patch 501 and ground plane 3; metal vias 605 and the lower half of the two rows of metal vias 601 form a row. Metal vias 604 are located at the front end of metal strip 102, passing vertically through upper and lower dielectric substrates 2 and 4, connecting the top metal strip 102 and the bottom rectangular metal patch 501.

[0026] In the above structure, the U-shaped metal patch 103, the rectangular metal patch 501, the upper dielectric substrate 2, the lower dielectric substrate 4, the metal via 601, the metal via 602, and the metal via 605 form a fundamental mode substrate-integrated waveguide resonator, i.e., the main resonator. The metal strip 104, the metal strip 502, the upper dielectric substrate 2, the lower dielectric substrate 4, and the metal via 603 form a dual open fundamental mode resonator, i.e., the auxiliary resonator. The metal strip 101, the upper dielectric substrate 2, and the metal ground 3 form a feed microstrip line. The metal strip 102, the U-shaped metal patch 103, the metal via 604, the upper dielectric substrate 2, the lower dielectric substrate 4, and the rectangular metal patch 501 form a coplanar waveguide feed probe.

[0027] For the proposed miniaturized substrate integrated waveguide flat-top-fire antenna, the signal is transmitted through the feed microstrip line to the coplanar waveguide feed probe, which in turn excites the fundamental mode substrate integrated waveguide resonator. Combined with the dual open fundamental mode resonator, a flat-top-fire antenna with miniaturization effect is achieved.

[0028] During this process, the metal strip 102 of the coplanar waveguide feed probe couples with the U-shaped metal patch 103, while the metal via 604, acting as the probe, transmits the signal to the bottom layer of the resonator, thereby exciting the fundamental mode substrate integrated waveguide resonator. After the antenna is excited, both the fundamental mode substrate integrated waveguide resonator and the dual-open fundamental mode resonator exhibit a vertical electric field distribution. However, with the assistance of the dual-open fundamental mode resonator, a relatively weaker vertical reverse electric field appears on both sides of the opening of the fundamental mode substrate integrated waveguide resonator. This weak reverse electric field, combined with the strong internal electric field, can form a flat-top radiation on the horizontal plane. Simultaneously, the dual-open fundamental mode resonator also improves the overall antenna gain. The antenna has a small overall horizontal dimension, thus exhibiting a miniaturized substrate integrated waveguide flat-top radiation effect.

[0029] In this invention, "strong vertical electric field" refers to the vertical electric field formed by the confinement of the closed resonant space inside the fundamental mode substrate integrated waveguide resonator, and "weak vertical reverse electric field" refers to the vertical electric field generated on both sides of the opening of the main resonator in the dual open fundamental mode resonator. The strength relationship between the two is judged by the criterion that "they can form uniform flat-top radiation after superposition". Those skilled in the art can achieve this strength difference by adjusting the resonator structural parameters.

[0030] The dielectric substrate used in this embodiment is an RO4003C substrate, and the radiator size is only 0.47λ0 × 0.32λ0 × 0.17λ0, which is relatively small. The simulated matching response of the antenna is as follows: Figure 3 As shown, from Figure 3 As can be seen, the 10-dB matching frequency range of this embodiment is 23.11~24.00 GHz, the center frequency is 23.52 GHz, and the relative bandwidth can reach 3.78%. Figure 4 The image shows the horizontal radiation pattern of the antenna at the center frequency (23.52 GHz). Stable gain was achieved within the range of phi = 155.76 to 204.24°, with the gain between 2.06 and 2.26 dBi. This indicates that the embodiment achieved flat-top radiation of the substrate integrated waveguide.

[0031] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A miniaturized substrate-integrated waveguide flat-top-firing antenna, characterized in that, include: At least one dielectric substrate, a metal ground (3), a metal structure layer disposed on the dielectric substrate, and a group of metal vias (6) penetrating the dielectric substrate and the metal ground (3). The metal structure layer is formed in conjunction with the metal via group (6) and the dielectric substrate: The main resonator is capable of generating a strong vertical electric field and has an opening for signal coupling. The main resonator includes a top metal patch, a bottom metal patch, and a first metal via subgroup. An auxiliary resonator is located in front of the radiation of the main resonator. It can generate a weak vertical electric field opposite to the strong vertical electric field on both sides of the opening of the main resonator. The weak vertical electric field and the strong vertical electric field are superimposed to form a flat-top radiation on a horizontal plane. The auxiliary resonator includes a top auxiliary metal strip, a bottom auxiliary metal strip, and a second metal via subgroup. A planar integrable power supply structure is provided, which can couple external signals to the main resonator and excite it to generate a strong vertical electric field, and is coplanarly integrated with the metal structure layer and the dielectric substrate.

2. The miniaturized substrate integrated waveguide flat-top-fire antenna according to claim 1, characterized in that, The top metal patch is a U-shaped metal patch (103), and the bottom metal patch is a rectangular metal patch (501), which are aligned vertically. The U-shaped metal patch (103) has a notch. The first metal via subgroup includes metal via one (601), metal via two (602), and metal via five (605). Metal via one (601) and metal via two (602) connect the U-shaped metal patch (103) and the rectangular metal patch (501) and form a resonant space around each other that can constrain a strong vertical electric field.

3. The miniaturized substrate integrated waveguide flat-top-fire antenna according to claim 2, characterized in that, The first metal via (601) is arranged horizontally on the top of the two arms of the U-shaped metal patch (103), and the second metal via (602) is arranged vertically on the outside of the two arms of the U-shaped metal patch (103). The two form two sets of L-shaped structures and pass vertically through the metal ground (3) and the dielectric substrate.

4. The miniaturized substrate integrated waveguide flat-top-fire antenna according to claim 2, characterized in that, The top auxiliary metal strip is metal strip three (104), and the bottom auxiliary metal strip is metal strip four (502), which are aligned vertically; the second metal via subgroup is metal via three (603), which are arranged vertically at both ends of metal strip three (104), passing vertically through the metal ground (3) and the dielectric substrate, connecting metal strip three (104) and metal strip four (502); the auxiliary resonator has no closed cavity and is open on both sides.

5. The miniaturized substrate integrated waveguide flat-top-fire antenna according to claim 1, characterized in that, The planar integrable power supply structure includes a power supply transmission line and a power supply probe. The power supply transmission line is a power supply microstrip line, which is composed of a metal strip (101), a dielectric substrate and a metal ground (3). The power supply probe is embedded in the notch of the U-shaped metal patch (103) of the main resonator and excites the main resonator through both coupling and signal transmission.

6. The miniaturized substrate integrated waveguide flat-top-fire antenna according to claim 5, characterized in that, The feed probe is a coplanar waveguide feed probe, including a second metal strip (102) and a fourth metal via (604). The second metal strip (102) is coupled to a U-shaped metal patch (103). The fourth metal via (604) is located at the front end of the second metal strip (102) and passes vertically through the dielectric substrate to connect the second metal strip (102) and the rectangular metal patch (501).

7. The miniaturized substrate integrated waveguide flat-top-fire antenna according to claim 1, characterized in that, The dielectric substrate includes an upper dielectric substrate (2) and a lower dielectric substrate (4), and the metal ground (3) is sandwiched between the upper dielectric substrate (2) and the lower dielectric substrate (4); the metal structure layer includes a top metal structure (1) and a bottom metal structure (5), which are respectively disposed on the upper surface of the upper dielectric substrate (2) and the lower surface of the lower dielectric substrate (4).

8. The miniaturized substrate integrated waveguide flat-top-fire antenna according to claim 1, characterized in that, The vertical dimension of the main resonator is 0.29λ0~0.33λ0, the horizontal dimension is between 0.29λ0~0.33λ0, and the width of the notch is between 0.11λ0~0.14λ0, where λ0 is the free space wavelength corresponding to the center frequency.

9. The miniaturized substrate integrated waveguide flat-top-fire antenna according to claim 4, characterized in that, The metal strip three (104) of the auxiliary resonator has a lateral length of 0.06λ0~0.10λ0 and a vertical width of 0.30λ0~0.34λ0.

10. The miniaturized substrate integrated waveguide flat-top-fire antenna according to claim 6, characterized in that, The length of the metal strip two (102) of the feed probe is 0.15λ0~0.20λ0.

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