Phase uniformization horn antenna based on slow wave structure
By loading a slow wave structure and a substrate integrated waveguide conversion structure on the aperture surface of the speaker antenna, the problems of uneven phase, poor directionality and large size in traditional speaker antennas in high-frequency communication systems are solved, and performance optimization of high gain, wide bandwidth and miniaturization is achieved.
Patent Information
- Application Number
- CN202510609600.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-13
- Publication Date
- 2025-08-12
AI Technical Summary
In high-frequency communication systems, traditional speaker antennas have problems such as uneven phase distribution of the aperture plane, poor radiation direction, reduced gain, narrow working bandwidth and large physical size, which is difficult to meet the high gain, wide bandwidth and miniaturization needs of modern communication systems.
The slow wave structure is loaded on the diameter surface of the horn antenna. By changing the equivalent dielectric constant of the medium to increase the phase constant, phase uniformization is achieved, and power is fed through the substrate integrated waveguide conversion structure, combining metal columns and metal patches to improve impedance matching and suppress side lobe radiation.
It significantly improves the directionality and gain of the antenna, expands the operating bandwidth, and optimizes its performance without increasing the overall size of the antenna, reduces signal interference, and meets the high gain, wide bandwidth and miniaturization needs of modern communication systems.
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Figure CN120473732A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of wireless communication technology, and specifically relates to a phase-homogenized horn antenna based on a slow-wave structure. Aiming at optimizing the performance of horn antennas in high-frequency communication systems (such as millimeter-wave communication, radar, and satellite communication), the slow-wave structure is introduced to achieve aperture-plane phase homogenization, thereby improving the antenna's radiation efficiency, directivity, and gain performance. Background Art
[0002] Traditional horn antennas are widely used in high-frequency communication systems in fields such as radar, satellite communications, and millimeter-wave communications. However, they have many technical limitations in practical applications. First, the aperture-plane phase distribution of existing horn antennas in high-frequency bands (such as millimeter-wave bands) is uneven, resulting in poor radiation directivity and reduced gain, making it difficult to meet the needs of long-distance communication and high-resolution detection. Second, their narrow operating bandwidth cannot meet the requirements of modern communication systems for wideband and multi-band support. In addition, the large physical size of traditional horn antennas makes them difficult to integrate into miniaturized devices, limiting their application in compact communication systems.
[0003] Horn antennas are classic microwave antennas, with major types including rectangular, conical, double-ridged, corrugated, and multimode. Each offers advantages in gain, bandwidth, or polarization characteristics, but they generally suffer from large size, difficulty balancing bandwidth and efficiency, insufficient polarization flexibility, and poor environmental adaptability. Current technological improvements focus on miniaturization, ultra-wideband design, low-cost manufacturing, reconfigurable technology, and thermal optimization. Future developments lie in multifunctional integration, intelligent control, and advanced manufacturing processes to meet the high-demand scenarios of 6G and terahertz communications. Summary of the Invention
[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a phase-homogenized horn antenna based on a slow-wave structure. The slow-wave structure is loaded on the aperture surface of the horn antenna to change the equivalent dielectric constant of the aperture surface medium, thereby improving the phase constant, thereby solving the problem of large phase difference on the aperture surface and achieving the purpose of miniaturization of the horn antenna.
[0005] The technical problem proposed by the present invention is solved as follows:
[0006] A phase-homogenizing horn antenna based on a slow-wave structure comprises an upper metal layer, an upper dielectric substrate, a lower dielectric substrate and a lower metal layer which are tightly attached to each other from top to bottom.
[0007] The upper dielectric substrate and the lower dielectric substrate are both rectangular in shape but of different thicknesses; the upper metal layer and the lower metal layer are both square in shape, with three sides reaching the edges of the upper dielectric substrate and the lower dielectric substrate respectively; periodically arranged vertical metal through-holes penetrate the upper dielectric substrate and the lower dielectric substrate, with their ends connected to the upper metal layer and the lower metal layer respectively; the periodically arranged metal through-holes and the edges of the upper metal layer structure enclose a horn shape, serving as the narrow wall of the horn antenna, forming a horn antenna based on a substrate integrated waveguide structure;
[0008] Periodically arranged rectangular metal patches are loaded on the upper surface of the upper dielectric substrate and the lower surface of the lower dielectric substrate, respectively, at the aperture of the horn antenna. Several metal pillars are loaded in the lower dielectric substrate, distributed in the corresponding area of the center of the horn antenna, with the bottom ends connected to the lower metal layer. The metal pillars and the upper metal layer at their corresponding positions, the upper dielectric substrate, and the lower metal layer constitute a slow-wave structure.
[0009] The horn antenna is fed through a conversion structure from substrate integrated waveguide to grounded coplanar waveguide.
[0010] Furthermore, the metal posts are arranged in a gradient from few to many from the input end to the aperture of the horn antenna.
[0011] Furthermore, the metal posts are arranged in five rows, and each row is parallel to the aperture of the horn antenna.
[0012] Furthermore, among the five rows of metal columns, from the input end to the aperture of the horn antenna, the number of the first row is set to 3, the number of the second row is set to 4, the number of the third row is set to 5, the number of the fourth row is set to 9, and the number of the fifth row is set to 10.
[0013] Furthermore, among the five rows of metal pillars, the spacing between the rows is equal, which is 1.4mm; the spacing of the metal pillars in the first row is 1.8mm, and the length is 3.6mm; the spacing of the metal pillars in the second row is 1.2mm, and the length is 3.6mm; the spacing of the metal pillars in the third row is 1mm, and the length is 4mm; the spacing of the metal pillars in the fourth row is 0.9mm, and the length is 7.2mm; the spacing of the metal pillars in the fifth row is 0.8mm, and the length is 7.2mm.
[0014] Furthermore, the loaded rectangular metal patches are distributed into two rows, with 25 in each row.
[0015] Furthermore, the dielectric material of the upper dielectric substrate and the lower dielectric substrate is Rogers RO4350.
[0016] Furthermore, the thicknesses of the upper dielectric substrate and the lower dielectric substrate are 1 mm and 0.508 mm respectively.
[0017] The beneficial effects of the present invention are:
[0018] The horn antenna described in the present invention introduces a periodic structure capable of regulating the propagation characteristics of electromagnetic waves as a slow-wave structure; the slow-wave structure reduces the phase velocity of the electromagnetic wave and enhances the distribution control capability of the electromagnetic field, thereby improving the impedance matching characteristics of the antenna, expanding the working bandwidth, and improving the radiation efficiency; integrating the slow-wave structure into the horn antenna can not only significantly improve the directivity and gain of the antenna, but also optimize its performance without increasing the overall size of the antenna. In addition, the introduction of the slow-wave structure can also effectively suppress sidelobe radiation, reduce signal interference, and further improve the overall performance of the antenna. The horn antenna described in the present invention meets the requirements of modern communication systems for high gain, wide bandwidth, and miniaturization, and also provides a high-performance antenna solution for application scenarios such as radar, satellite communications, and millimeter-wave communications. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 This is a schematic diagram of the overall structure of the horn antenna of the present invention;
[0020] Figure 2 A top view of the horn antenna of the present invention;
[0021] Figure 3 Schematic diagram of the slow-wave structure in the horn antenna of the present invention;
[0022] Figure 4 Schematic diagram of the distribution of slow-wave structures in the horn antenna of the present invention;
[0023] Figure 5 This is the electric field amplitude diagram of the horn antenna loaded with a slow-wave structure at 28 GHz described in the embodiment;
[0024] Figure 6 The electric field amplitude diagram of the horn antenna at 28GHz without loading the slow-wave structure;
[0025] Figure 7 This is the electric field phase diagram of the horn antenna loaded with a slow-wave structure at 28 GHz described in the embodiment;
[0026] Figure 8 This is the electric field phase diagram of the horn antenna at 28GHz without loading the slow-wave structure. DETAILED DESCRIPTION
[0027] The present invention will be further described below with reference to the accompanying drawings and examples.
[0028] This embodiment provides a phase-homogenized horn antenna based on a slow-wave structure, and its three-dimensional structure diagram is shown in FIG. Figure 1 As shown, the top view is Figure 2As shown, the upper metal layer, upper dielectric substrate, lower dielectric substrate, and lower metal layer are tightly bonded together from top to bottom. Rogers RO4350 is used as the dielectric material for the upper and lower dielectric substrates. The thicknesses of the upper and lower dielectric substrates are 1 mm and 0.508 mm, respectively.
[0029] The upper dielectric substrate and the lower dielectric substrate are both rectangular in shape but of the same size but with different thicknesses; the upper metal layer and the lower metal layer are both square in shape, with three sides reaching the edges of the upper dielectric substrate and the lower dielectric substrate respectively; periodically arranged vertical metal through holes penetrate the upper dielectric substrate and the lower dielectric substrate, with both ends connected to the upper metal layer and the lower metal layer respectively; the periodically arranged metal through holes and the edges of the upper metal layer structure enclose a horn shape, serving as the narrow wall of the horn antenna, forming a horn antenna based on a substrate integrated waveguide structure.
[0030] The upper surface of the upper dielectric substrate and the lower surface of the lower dielectric substrate corresponding to the aperture of the horn antenna are loaded with periodically arranged rectangular metal patches, distributed in two rows, with 25 patches in each row, as an impedance matching structure, mainly used to improve the matching between the antenna and free space, thereby improving the return loss of the antenna; the lower dielectric substrate is loaded with a number of metal columns, distributed in the corresponding area of the central part of the horn antenna, and the bottom end is connected to the lower metal layer. The metal columns and the upper metal layer at their corresponding positions, the upper dielectric substrate, and the lower metal layer constitute a slow wave structure, such as Figure 3 shown.
[0031] The horn antenna is fed through a conversion structure from a substrate integrated waveguide to a grounded coplanar waveguide. The antenna feeding structure (6, 7) adopts a conversion structure of a SIW and a grounded coplanar waveguide (GCPW). The conversion structure of the SIW and GCPW consists of a coplanar waveguide connected to a coaxial connector, two tapered slots, and lateral walls using SIW technology (i.e., SIW through holes on both sides of the tapered slot). The lateral wall spacing and the coupling slot (tapered slot) width are tapered to suppress high-order waveguide modes in the GCPW section and help excite the dominant TE10 mode in the SIW section, thereby improving the bandwidth.
[0032] like Figure 4As shown, the metal pillars are arranged in a gradient from the input end to the aperture of the horn antenna. The metal pillars are arranged in five rows, each parallel to the aperture of the horn antenna. The number of metal pillars in the first row is 3, the second row is 4, the third row is 5, the fourth row is 9, and the fifth row is 10. The spacing between rows is equal, at 1.4mm. The spacing between the metal pillars in the first row is 1.8mm, and the length is 3.6mm; the spacing between the metal pillars in the second row is 1.2mm, and the length is 3.6mm; the spacing between the metal pillars in the third row is 1mm, and the length is 4mm; the spacing between the metal pillars in the fourth row is 0.9mm, and the length is 7.2mm; and the spacing between the metal pillars in the fifth row is 0.8mm, and the length is 7.2mm.
[0033] The horn antenna described in this embodiment comprises a double-layer dielectric substrate, with metal patches covering the upper and lower surfaces. The feed structure is located on the upper surface of the upper dielectric substrate. The antenna's sidewalls utilize SIW technology, constructed with adjacent periodic metal through-holes. These holes gradually expand from the feed waveguide to the horn antenna's aperture. Metal blind vias forming a slow-wave structure are located in the lower dielectric substrate within the aperture. Metal patches are added to the antenna aperture to improve bandwidth and serve as an impedance matching structure.
[0034] As a new type of artificial electromagnetic surface, a slow-wave structure can reduce the phase velocity of electromagnetic waves propagating through a transmission line by altering distributed parameters such as the dielectric constant or magnetic permeability through a periodic unit structure. This reduces the guided wavelength of electromagnetic waves within the corresponding operating frequency band, while increasing the phase constant. The slow-wave structure described in this invention utilizes metal blind vias, with metal layers on the upper and lower surfaces and a double dielectric layer in the middle, one layer loaded with metal blind vias and the other without.
[0035] By loading periodic metal blind holes in the center region of the trapezoidal structure of an H-plane horn antenna, the phase constant in the center region is made greater than that in the edge regions. Based on the relationship between phase change, phase constant, and distance, this method can compensate for the distance difference caused by different distances. As the wide side of the angular area gradually increases, the phase constant also gradually increases, further exacerbating the phase difference problem. Therefore, it is necessary to load a slow-wave structure with a larger effective dielectric constant in the center region to better compensate for the greater phase difference caused by the increased phase constant.
[0036] When periodic metal blind holes are arranged more densely in a single direction, the phase increases, and the effective dielectric constant increases. Furthermore, as the wideband of the H-plane horn antenna's angular area gradually increases, the area requiring adjustment also increases along the wideband direction. Therefore, the slow-wave structure's coverage along the horn antenna's wideband direction increases to accommodate changes in the antenna's angular area.
[0037] A comparative simulation was performed on the horn antenna of this embodiment and a horn antenna without a slow-wave structure loaded thereon. Figure 5 This is the electric field amplitude diagram of the horn antenna loaded with a slow-wave structure at 28 GHz described in the embodiment; Figure 6 The electric field amplitude diagram of the horn antenna at 28GHz without loading the slow-wave structure; Figure 7 This is the electric field phase diagram of the horn antenna loaded with a slow-wave structure at 28 GHz described in the embodiment; Figure 8 This is the electric field phase diagram of the horn antenna at 28GHz without loading the slow-wave structure.
[0038] It can be seen that the electromagnetic wave propagation of the antenna without the slow-wave structure in the angular region is similar to that of a cylindrical wave. In contrast, the antenna loaded with the slow-wave structure has a more uniform phase and a significantly smaller phase difference between the center and edge of the antenna angular region, and the wavefront is closer to a plane wave.
[0039] Simulation results show that using substrate integrated waveguide technology to design antennas and loading slow-wave structures is beneficial to adjusting the problem of excessive aperture plane phase difference.
[0040] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make several improvements and modifications without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A phase-homogenizing horn antenna based on a slow-wave structure, characterized in that: It includes an upper metal layer, an upper dielectric substrate, a lower dielectric substrate and a lower metal layer that are tightly attached to each other from top to bottom; The upper dielectric substrate and the lower dielectric substrate are both rectangular in shape but of different thicknesses; the upper metal layer and the lower metal layer are both square in shape, with three sides reaching the edges of the upper dielectric substrate and the lower dielectric substrate respectively; periodically arranged vertical metal through-holes penetrate the upper dielectric substrate and the lower dielectric substrate, with their ends connected to the upper metal layer and the lower metal layer respectively; the periodically arranged metal through-holes and the edges of the upper metal layer structure enclose a horn shape, serving as the narrow wall of the horn antenna, forming a horn antenna based on a substrate integrated waveguide structure; Periodically arranged rectangular metal patches are loaded on the upper surface of the upper dielectric substrate and the lower surface of the lower dielectric substrate corresponding to the aperture of the horn antenna. The lower dielectric substrate is loaded with a number of metal pillars, which are distributed in the corresponding area of the central part of the horn antenna. The bottom ends are connected to the lower metal layer. The metal pillars and the upper metal layer at their corresponding positions, the upper dielectric substrate, and the lower metal layer constitute a slow-wave structure. The horn antenna is fed through a conversion structure from substrate integrated waveguide to grounded coplanar waveguide.
2. The phase-homogenizing horn antenna based on a slow-wave structure according to claim 1, characterized in that: The metal poles are arranged in a gradient from few to many from the input end to the aperture of the horn antenna.
3. The phase-homogenizing horn antenna based on a slow-wave structure according to claim 2, characterized in that: The metal columns are arranged in five rows, and each row is parallel to the aperture of the horn antenna.
4. The phase-homogenizing horn antenna based on a slow-wave structure according to claim 3, characterized in that: Among the five rows of metal columns, from the input end of the horn antenna to the aperture, the number of the first row is set to 3, the number of the second row is set to 4, the number of the third row is set to 5, the number of the fourth row is set to 9, and the number of the fifth row is set to 10.
5. The phase-homogenizing horn antenna based on a slow-wave structure according to claim 4, characterized in that: Among the five rows of metal pillars, the spacing between each row is equal, which is 1.4mm; the spacing of the metal pillars in the first row is 1.8mm, and the length is 3.6mm; the spacing of the metal pillars in the second row is 1.2mm, and the length is 3.6mm; the spacing of the metal pillars in the third row is 1mm, and the length is 4mm; the spacing of the metal pillars in the fourth row is 0.9mm, and the length is 7.2mm; the spacing of the metal pillars in the fifth row is 0.8mm, and the length is 7.2mm.
6. The phase-homogenizing horn antenna based on a slow-wave structure according to claim 1, characterized in that: The loaded rectangular metal patches are distributed in two rows, with 25 in each row.
7. The phase-homogenizing horn antenna based on a slow-wave structure according to claim 1, characterized in that: The dielectric material of the upper dielectric substrate and the lower dielectric substrate is Rogers RO4350.
8. The phase-homogenizing horn antenna based on a slow-wave structure according to claim 1, characterized in that: The thicknesses of the upper dielectric substrate and the lower dielectric substrate are 1 mm and 0.508 mm respectively.