Broadband millimeter wave circularly polarized antenna array based on SIW feed
The broadband millimeter-wave circularly polarized antenna array, designed with SIW feeding structure optimization, solves the bandwidth and size limitations of existing technologies, achieving wide bandwidth, high gain and low loss performance, and is suitable for multi-band wireless communication devices.
Patent Information
- Application Number
- CN202511914997.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-18
- Publication Date
- 2026-01-30
AI Technical Summary
Existing millimeter-wave circularly polarized antenna arrays have shortcomings in bandwidth performance, size, and power supply network design, making it difficult to achieve wide bandwidth, miniaturization, and low loss, thus limiting their application in high-speed data transmission and space-constrained devices.
The design employs a SIW feed structure, which includes an antenna array composed of multiple layers of metal and dielectric layers. It combines a SIW rectangular feed cavity, a power divider structure, and a tuning via to optimize the antenna radiating element and slot design, forming a broadband millimeter-wave circularly polarized antenna array.
It achieves a broadband operating bandwidth of 29.9~41.5 GHz, an absolute bandwidth of 11.6 GHz, a gain of 14.3 dB, and an axial ratio bandwidth of 29.9~37.54 GHz, making it suitable for multi-band wireless applications, improving signal transmission distance and anti-multipath interference capabilities, and applicable to scenarios such as smart terminals and vehicle-mounted millimeter-wave radar.
Smart Images
Figure CN121440141A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of antenna technology, specifically relating to a broadband millimeter-wave circularly polarized antenna array based on SIW feeding. Background Technology
[0002] With the widespread adoption of fifth-generation mobile communication technology (5G) and the gradual advancement of research into sixth-generation mobile communication technology (6G), the demand for high-frequency bands, high capacity, high reliability, and low latency in the field of wireless communication is experiencing explosive growth. Under this trend, millimeter-wave bands, with their significant advantages such as wide bandwidth, large capacity, and high resolution, have become the core research direction for next-generation wireless communication technologies.
[0003] In millimeter-wave communication systems, antennas are crucial components for signal transmission and reception, and their performance directly impacts the overall system quality. Circularly polarized antenna arrays, due to their ability to effectively overcome multipath fading and polarization mismatch, have been widely used in satellite communications, high-speed mobile terminal communications, and other scenarios. However, existing millimeter-wave circularly polarized antenna arrays still face numerous challenges in practical applications.
[0004] In terms of bandwidth performance, traditional millimeter-wave circularly polarized antenna arrays often struggle to achieve a wide operating bandwidth. For example, some array designs based on microstrip patch antennas or cavity antennas typically have a 3dB axial ratio bandwidth of less than 10%, which severely limits the effective transmission range and data throughput in broadband applications requiring high-speed data transmission.
[0005] In terms of antenna size, many circularly polarized antenna arrays are relatively large in order to meet the requirements of high gain, which is not conducive to the miniaturization and integration of equipment. Especially in some space-constrained applications, such as handheld mobile devices and small drones, the excessively large antenna size has become a key factor hindering their application.
[0006] Furthermore, complex feed network designs not only increase the manufacturing cost of the antenna, but may also introduce additional transmission losses, reducing the overall performance of the antenna.
[0007] In conclusion, developing a millimeter-wave circularly polarized antenna array with wide bandwidth, miniaturization, low loss, and high gain is of significant practical importance and has an urgent market demand. Summary of the Invention
[0008] The technical problem to be solved by the present invention is to provide a broadband millimeter-wave circularly polarized antenna array based on SIW feeding, which addresses the shortcomings of the prior art. The broadband millimeter-wave circularly polarized antenna array of the present invention has advantages such as a wide circular polarization operating bandwidth, small size and high far-field gain.
[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a broadband millimeter-wave circularly polarized antenna array based on SIW feeding, comprising, from top to bottom, a first metal layer, a first dielectric layer, an adhesive layer, a second metal layer, a second dielectric layer, a third metal layer, a third dielectric layer, and a fourth metal layer; the second dielectric layer is provided with a plurality of SIW rectangular feeding cavities, and the second metal layer is provided with a first rectangular slot; the third dielectric layer is provided with a one-to-four SIW power divider structure.
[0010] Preferably, the first metal layer has four quasi-square cutouts, each of which has an antenna radiating element at its center. The four antenna radiating elements are arranged in a 90° rotational arrangement. Each antenna radiating element includes a pair of arrow-shaped main radiating patches and a pair of quasi-square parasitic patches with triangular chamfers. The arrow-shaped main radiating patches are located on both sides of the first rectangular gap.
[0011] Preferably, the first dielectric layer is provided with a first group of metal pillar through holes, which are evenly distributed around the periphery of the quasi-square hollow; the upper end of the first group of metal pillar through holes is connected to the first metal layer.
[0012] Preferably, the second dielectric layer is provided with four SIW rectangular feed cavities, each of which includes a second group of metal pillar vias and a third group of metal pillar vias; one end of the second group of metal pillar vias and the third group of metal pillar vias are connected to the second metal layer, and the other end of the third group of metal pillar vias is connected to the third metal layer.
[0013] Preferably, the second metal layer is provided with four first tuning vias, which are respectively located in the four SIW rectangular feed cavities; the second metal layer is also provided with four first rectangular slots, which are respectively located in the four SIW rectangular feed cavities.
[0014] Preferably, the 1-to-4 SIW power divider structure includes a fourth group of metal pillar through-holes and a fifth group of metal pillar through-holes; a second tuning through-hole and a third tuning through-hole are vertically disposed through the third metal layer, the third dielectric layer and the fourth metal layer; one end of the fourth group of metal pillar through-holes and the fifth group of metal pillar through-holes are connected to the third metal layer and the other end is connected to the fourth metal layer.
[0015] Preferably, the third metal layer has four elongated second rectangular slits that are distributed in sequence by rotating 90°.
[0016] Preferably, the fourth metal layer is a metal grounding layer, and a power supply port is provided at the center of the fourth metal layer.
[0017] Compared with the prior art, the present invention has the following advantages:
[0018] 1. The present invention discloses a broadband millimeter-wave circularly polarized antenna array based on SIW feeding, with an S11 bandwidth of 29.9~41.5 GHz and an absolute bandwidth of 11.6 GHz, covering multiple wireless applications operating in the millimeter-wave frequency band. Its broadband characteristics make it suitable for products such as smart terminals and vehicle-mounted millimeter-wave radars that work in multi-band coordination.
[0019] 2. This invention provides a broadband millimeter-wave circularly polarized antenna array based on SIW feeding, achieving a maximum in-band gain of 14.3 dB and maintaining high gain stability (gain fluctuation less than 3 dB) throughout the entire operating bandwidth. This advantage directly increases the effective transmission distance of the signal (at the same transmit power, the transmission distance increases by approximately 41% for every 3 dB increase in gain), while also enhancing resistance to multipath interference. It is particularly suitable for scenarios with stringent signal quality requirements, such as millimeter-wave imaging and long-distance wireless backhaul, significantly improving the system's communication or detection performance compared to existing technologies.
[0020] 3. This invention discloses a broadband millimeter-wave circularly polarized antenna array based on SIW feeding, with an axial ratio bandwidth of 29.9~37.54 GHz. This means that in most operating frequency bands, the antenna can maintain good impedance matching (S11≤-10 dB) and achieve high-purity circularly polarized radiation (axial ratio≤3 dB). This characteristic makes it promising for applications requiring stable circular polarization performance (such as satellite communication and polarization diversity radar), minimizing polarization mismatch loss and improving system link reliability.
[0021] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. Attached Figure Description
[0022] Figure 1 This is a three-dimensional structural schematic diagram of the broadband millimeter-wave circularly polarized antenna array in this invention;
[0023] Figure 2 This is a side view of the broadband millimeter-wave circularly polarized antenna array in this invention;
[0024] Figure 3 This is a schematic diagram of the planar structure of the first metal layer in this invention;
[0025] Figure 4 This is a schematic diagram of the planar structure of the second metal layer in this invention;
[0026] Figure 5 This is a schematic diagram of the planar structure of the third metal layer in this invention;
[0027] Figure 6This is a schematic diagram of the planar structure of the fourth metal layer in this invention;
[0028] Figure 7 The figure shows the simulation results of the relationship between the reflection coefficient and frequency of the broadband millimeter-wave circularly polarized antenna array in this invention.
[0029] Figure 8 The figure shows the simulation results of the relationship between the axial ratio and frequency of the broadband millimeter-wave circularly polarized antenna array in Example 1.
[0030] Figure 9 The figure shows the simulation results of the relationship between gain and frequency of the broadband millimeter-wave circularly polarized antenna array in Example 1.
[0031] Figure 10 The image shows the far-field radiation pattern of the broadband millimeter-wave circularly polarized antenna array at 32 GHz in Example 1.
[0032] Figure 11 The image shows the far-field radiation pattern of the broadband millimeter-wave circularly polarized antenna array at 32 GHz in Example 1.
[0033] Figure 12 The image shows the far-field radiation pattern of the broadband millimeter-wave circularly polarized antenna array at 35 GHz in Example 1.
[0034] Figure 13 The image shows the far-field radiation pattern of the broadband millimeter-wave circularly polarized antenna array at 35 GHz in Example 1.
[0035] Figure 14 The image shows the far-field radiation pattern of the broadband millimeter-wave circularly polarized antenna array at 36 GHz in Example 1.
[0036] Figure 15 This is the far-field radiation pattern of the broadband millimeter-wave circularly polarized antenna array at 36 GHz in Example 1.
[0037] Explanation of reference numerals in the attached drawings: 1. First dielectric layer; 2. Adhesive layer; 3. Second dielectric layer; 4. Third dielectric layer; 5. First metal layer; 501. Quasi-square cutout; 502. Arrow-shaped main radiating patch; 503. Quasi-square parasitic patch; 6. Second metal layer; 601. First rectangular slot; 602. First tuning via; 7. Third metal layer; 701. Second rectangular slot; 8. Fourth metal layer; 9. First group of metal pillar vias; 10. Second group of metal pillar vias; 11. Third group of metal pillar vias; 12. Fourth group of metal pillar vias; 13. Fifth group of metal pillar vias; 14. Second tuning via; 15. Third tuning via; 16. Feed port. Detailed Implementation
[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0039] Example 1
[0040] This embodiment provides a broadband millimeter-wave circularly polarized antenna array based on SIW feeding, combined with Figure 1 and Figure 2 It includes, from top to bottom, a first metal layer 5, a first dielectric layer 1, an adhesive layer 2, a second metal layer 6, a second dielectric layer 3, a third metal layer 7, a third dielectric layer 4, and a fourth metal layer 8 (also called a metal floor layer).
[0041] Four SIW feeding cavities are provided in the second dielectric layer 3. Each SIW feeding cavity is composed of a second group of metal pillar vias 10 and a third group of metal pillar vias 11. A one-to-four SIW cavity power divider structure is provided in the third dielectric layer 4. The one-to-four SIW cavity power divider structure is composed of a fourth group of metal pillar vias 12 and a fifth group of metal pillar vias 13. A first rectangular slot 601 is provided on the second metal layer 6.
[0042] Combination Figure 1 , Figure 2 and Figure 3 The first metal layer 5 has four quasi-square cutouts 501 with triangular chamfers. Each quasi-square cutout 501 contains an antenna radiating element. The four antenna radiating elements are arranged in a 90° rotation. Each antenna radiating element includes a pair of arrow-shaped main radiating patches 502 and a pair of quasi-square parasitic patches 503 with triangular chamfers. The side length of the quasi-square parasitic patch 503 is 1.4 mm, and the chamfer length is 0.4 mm. In order to improve the antenna gain, the first metal pillar through-hole group 9 is arranged around the quasi-square cutouts 501. The arrow-shaped main radiating patches 502 are located on both sides of the first rectangular slot 601, and the pair of quasi-square parasitic patches 503 with triangular chamfers are used to expand the circular polarization working bandwidth.
[0043] A first metal pillar through-hole group 9 is provided in the first dielectric layer 1. The first metal pillar through-hole group 9 is evenly distributed around the four quasi-square hollows 501 to form a quasi-metal cavity, which can effectively reduce the electromagnetic wave energy leaked to the surroundings, thereby improving the far-field gain of the antenna array in the axial direction.
[0044] Combination Figure 1 , Figure 2 and Figure 4Four SIW rectangular feed cavities are disposed in the second dielectric layer 3. The four SIW rectangular feed cavities are arranged in a manner that rotates 90° sequentially, and have different lengths. The lengths of the four SIW rectangular feed cavities are set as L1, L2, L3 and L4, respectively. Each SIW rectangular feed cavity includes a second group of metal pillar vias 10 and a third group of metal pillar vias 11. By etching a slender first rectangular slot 601 along the long side of the SIW rectangular feed cavity on the second metal layer 6, electromagnetic energy is excited to the antenna through the first rectangular slot 601. The length of the first rectangular slot 601 is 3.8 mm and the width is 0.55 mm. In order to improve the impedance matching of the antenna, a first tuning via 602 is provided in each SIW rectangular feed cavity.
[0045] The second metal layer 6 is provided with four elongated first rectangular feed slots 601 and four first tuning through holes 602; the four first tuning through holes 602 are respectively located in the four SIW rectangular feed cavities, and the four first rectangular slots 601 are respectively located in the four SIW rectangular feed cavities.
[0046] Combination Figure 1 , Figure 2 and Figure 5 A 1-to-4 SIW power divider structure is provided in the third dielectric layer 4. The 1-to-4 SIW power divider structure includes a fourth group of metal pillar vias 12 and a fifth group of metal pillar vias 13. The lengths of the 1-to-4 SIW power divider structure are set to L5, L6, L7 and L8 to generate a phase difference of 90° in sequence. In order to couple energy to the SIW rectangular feed cavity located in the second dielectric layer 3, four second rectangular slots 701 are provided on the third metal layer 7. The length of the second rectangular slots 701 is 4mm and the width is 3mm. In order to adjust the impedance matching of the antenna, four second tuning vias 14 and four third tuning vias 15 are provided. The second tuning vias 14 and 15 are vertically arranged through the third metal layer 7, the third dielectric layer 4 and the fourth metal layer 8. The second tuning vias 14 and 15 are located in the SIW rectangular feed cavity.
[0047] Figure 5 As shown, four elongated second rectangular slots 701 are arranged on the third metal layer 7 in a sequentially rotated 90° distribution. These slots can couple energy from the one-to-four SIW power divider structure to the SIW rectangular feed cavity located in the second dielectric layer 3, and then couple it to the antenna radiating element through the first rectangular slot 601 located on the second metal layer 6.
[0048] Figure 6 This embodiment provides a schematic diagram of the planar structure of the fourth metal layer 8 in a SIW-fed broadband millimeter-wave circularly polarized antenna array, as shown below. Figure 6As shown, a power supply port 16 is provided at the center of the fourth metal layer 8, and four second tuning vias 14 are symmetrically arranged around the power supply port 16.
[0049] The first dielectric layer 1 has a thickness of 0.813 mm, is made of Rogers RO4003, has a dielectric constant of 3.55, and a loss tangent of 0.0027. The adhesive layer 2 has a thickness of 0.1 mm, is made of Rogers RO4450F, has a dielectric constant of 3.5, and a loss tangent of 0.004. The second dielectric layer 3 and the third dielectric layer 4 both have a thickness of 0.508 mm, are made of Rogers RO5880, have a dielectric constant of 2.2, and a loss tangent of 0.0009.
[0050] The through-holes in the first metal pillar through-hole group 9 have a radius of 0.525 mm and a spacing of 1.865 mm. The upper end of the first metal pillar through-hole group 9 is connected to the first metal layer 5 to block electromagnetic energy from spreading to the surroundings, thereby improving the far-field gain of the antenna. The through-holes in the second metal pillar through-hole group 10 have a radius of 0.2 mm and a spacing of 0.75 mm. The through-holes in the third metal pillar through-hole group 11 have a radius of 0.15 mm and a spacing of 0.48 mm. One end of both the second metal pillar through-hole group 10 and the third metal pillar through-hole group 11 is connected to the second metal layer 6, and the other end is connected to the third metal layer 7. The through-holes in the fourth metal pillar through-hole group 12 have a radius of 0.2 mm and a spacing of 0.75 mm. The through-holes in the fifth metal pillar through-hole group 13 have a radius of 0.15 mm and a spacing of 0.48 mm. One end of both the fourth metal pillar through-hole group 12 and the fifth metal pillar through-hole group 13 is connected to the third metal layer 7, and the other end is connected to the fourth metal layer 8.
[0051] The reflection coefficient, far-field gain, and axial ratio of a broadband millimeter-wave circularly polarized antenna array based on SIW feeding in this embodiment were simulated and calculated using the electromagnetic simulation software ANSYS HFSS. The simulation results are as follows: Figures 7-15 As shown.
[0052] like Figure 7 The figure shown is a simulation result diagram illustrating the relationship between the reflection coefficient and frequency of a broadband millimeter-wave circularly polarized antenna array based on SIW feeding in this embodiment. From... Figure 7 As can be seen, the broadband millimeter-wave circularly polarized antenna array in this embodiment operates in a bandwidth of 29.9~41.5 GHz, and its reflection coefficient remains less than -10 dB.
[0053] like Figure 8 The figure shown is a simulation result diagram illustrating the relationship between the axial ratio and frequency of a broadband millimeter-wave circularly polarized antenna array based on SIW feeding in this embodiment. From... Figure 8As can be seen from the data, the axial ratio bandwidth of the broadband millimeter-wave circularly polarized antenna array in this embodiment is 29.9–37.54 GHz.
[0054] like Figure 9 The figure shown is a simulation result diagram illustrating the relationship between gain and frequency of a broadband millimeter-wave circularly polarized antenna array based on SIW feeding in this embodiment. From... Figure 9 As can be seen, the broadband millimeter-wave circularly polarized antenna array in this embodiment has a stable gain within the operating bandwidth, with a maximum gain of approximately 14.3 dBic.
[0055] like Figures 10-15 As shown, the far-field radiation patterns of the XOZ and YOZ principal planes of a broadband millimeter-wave circularly polarized antenna array based on SIW feeding in this embodiment are presented at 32 GHz, 35 GHz, and 36 GHz, respectively. The simulation results show that the broadband millimeter-wave circularly polarized antenna array operates in left-hand circular polarization mode throughout the entire operating frequency band, with the maximum radiation direction basically located in the +z axis direction, without significant offset or split lobes. Within the 3 dB beam range, the left-hand circular polarization gain level is approximately 20 dB higher than the right-hand circular polarization gain level, indicating that the broadband millimeter-wave circularly polarized antenna array has high polarization purity.
[0056] The simulation results above show that the broadband millimeter-wave circularly polarized antenna array based on SIW feeding in this embodiment has a wide operating bandwidth and stable left-hand circularly polarized radiation characteristics throughout the entire operating frequency band.
[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.
Claims
1. A wideband millimeter wave circularly polarized antenna array based on SIW feed, characterized in that, It comprises first metal layer (5), first dielectric layer (1), adhesive layer (2), second metal layer (6), second dielectric layer (3), third metal layer (7), third dielectric layer (4) and fourth metal layer (8) arranged in turn from top to bottom; A plurality of SIW rectangular feeding cavities are arranged in the second dielectric layer (3), and a first rectangular slot (601) is arranged on the second metal layer (6); A one-to-four SIW power division structure is arranged in the third dielectric layer (4).
2. The wideband millimeter-wave circularly polarized antenna array based on SIW feed according to claim 1, wherein, Four quasi-square hollows (501) are arranged on the first metal layer (5), and an antenna radiation unit is arranged at the center of each quasi-square hollow (501), and four antenna radiation units are distributed in turn with an angle of 90°, each antenna radiation unit comprises a pair of arrow-shaped main radiation patches (502) and a pair of quasi-square parasitic patches (503) with triangular cut corners, and the arrow-shaped main radiation patch (502) is located on both sides of the first rectangular slot (601).
3. The wideband millimeter-wave circularly polarized antenna array based on SIW feed according to claim 2, wherein, A first metal column via group (9) is arranged in the first dielectric layer (1), and the first metal column via group (9) is uniformly distributed on the periphery of the quasi-square hollow (501); The upper end of the first metal via group (9) is connected with the first metal layer (5).
4. The wideband millimeter-wave circularly polarized antenna array based on SIW feed according to claim 1, wherein, Four SIW rectangular feeding cavities are arranged in the second dielectric layer (3), each SIW rectangular feeding cavity comprises a second metal column via group (10) and a third metal column via group (11); One end of the second metal column via group (10) and the third metal column via group (11) is connected with the second metal layer (6), and the other end is connected with the third metal layer (7).
5. The wideband millimeter-wave circularly polarized antenna array based on SIW feed according to claim 4, wherein, Four first tuning vias (602) are arranged on the second metal layer (6), and four first tuning vias (602) are arranged in four SIW rectangular feeding cavities respectively; Four first rectangular slots (601) are further arranged on the second metal layer (6), and four first rectangular slots (601) are arranged in four SIW rectangular feeding cavities respectively.
6. The wideband millimeter-wave circularly polarized antenna array based on SIW feed according to claim 1, wherein, The one-to-four SIW power division structure comprises a fourth metal column via group (12) and a fifth metal column via group (13); A second tuning via (14) and a third tuning via (15) are vertically arranged on the third metal layer (7), the third dielectric layer (4) and the fourth metal layer (8); One end of the fourth metal column via group (12) and the fifth metal column via group (13) is connected with the third metal layer (7), and the other end is connected with the fourth metal layer (8).
7. The wideband millimeter-wave circularly polarized antenna array based on SIW feed according to claim 1, wherein, Four elongated second rectangular slots (701) are arranged on the third metal layer (7) in turn with an angle of 90°.
8. The wideband millimeter-wave circularly polarized antenna array based on SIW feed according to claim 1, wherein, The fourth metal layer (8) is a metal ground layer, and a feeding port (16) is arranged at the center of the fourth metal layer (8).