A ridge waveguide antenna integrated with a metasurface
By adopting an integrated metasurface ridge waveguide antenna design in the vehicle-mounted millimeter wave radar antenna, using the coupling feeding of the metasurface array and the ridge waveguide, the problems of high cost and poor performance in the high frequency band of the vehicle-mounted millimeter wave radar antenna are solved, and the problem of high frequency band poor performance is achieved. Higher bandwidth and service life.
Patent Information
- Application Number
- CN202411404703.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-10
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2044-10-10
AI Technical Summary
The existing vehicle-mounted millimeter-wave radar antennas have high cost and poor performance in the high frequency band, and are easily affected by the external environment, reducing their service life.
Using an integrated metasurface ridge waveguide antenna design, the coupling feeding is reduced by setting the metasurface array and the ridge waveguide slot layer on the lower side of the radome to reduce dielectric loss, and attaching the metasurface array through printing or laser direct molding technology, introducing Additional resonance points to broaden the bandwidth.
Reduces antenna costs, broadens bandwidth, improves service life, and simplifies structure and processing processes.
Smart Images
Figure CN118920089B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to an antenna, in particular to a ridge waveguide antenna integrated with a super surface, and belongs to the technical field of antennas. Background Art
[0002] With the continuous development of wireless communication technology, vehicle-mounted millimeter-wave radar antennas are increasingly used in intelligent transportation systems. As a key component of the radar system, the performance of the vehicle-mounted millimeter-wave radar antenna directly affects the detection distance, accuracy and reliability of the radar system. In the design of vehicle-mounted millimeter-wave radar antennas, the existence of the antenna cover is also very critical. It protects the antenna from the influence of the external environment, while also protecting the normal operation of the antenna and extending the service life of the antenna. However, the traditional vehicle-mounted antenna design has certain limitations, such as narrow bandwidth, gain affected by physical size, and complex feeding circuits.
[0003] Chinese patent publication number CN110197947B discloses an integrated substrate gap waveguide fed slot-coupled metasurface antenna, which uses a substrate integrated waveguide as a transmission line to etch slots on a copper-clad board to couple the metasurface. Such a design requires a multi-layer structure and uses a multi-layer dielectric substrate. In the 76-79GHz vehicle-mounted, as the frequency increases, the dielectric loss of the dielectric substrate increases, and it is expensive. Such a design will increase the cost of the antenna and affect the antenna performance in the high frequency band.
[0004] Chinese patent publication number CN111697333 A discloses a metamaterial radome, on which a square ring metasurface is placed. Its main application is to reduce the side lobes of the antenna, and metasurfaces are placed on both the upper and lower layers of the radome. Such a design places the metasurface on the outside and is also easily affected by the external environment, which can easily reduce the service life of the antenna.
[0005] It can be seen that the cost of existing antennas is relatively high and their performance in the high-frequency band is relatively poor, while the application of metasurfaces is mainly used to reduce antenna side lobes and is easily affected by the external environment, thus reducing the life of the antenna. Summary of the invention
[0006] The technical problem to be solved by the present invention is to provide a ridge waveguide antenna with an integrated metasurface, which reduces the antenna cost and expands the antenna bandwidth.
[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:
[0008] A ridge waveguide antenna with integrated metasurface comprises an antenna cover, a metasurface array, an antenna slot layer and a ridge waveguide, wherein the antenna slot layer is arranged on the upper side of the ridge waveguide, the metasurface array is arranged on the lower side of the antenna cover, the antenna cover is located above the antenna slot layer, there is a gap between the lower side of the metasurface array and the upper surface of the antenna slot layer, and the metasurface array is composed of multiple metasurface patches distributed in an array to introduce additional resonance points.
[0009] Furthermore, the ridge waveguide adopts a single ridge waveguide antenna unit.
[0010] Furthermore, the ridge waveguide includes two ridge waveguide antenna units, which are arranged symmetrically in the same direction to form an array, and the two ridge waveguide antenna units are respectively connected to two output ends of a one-to-two ridge waveguide power divider.
[0011] Furthermore, the metasurface array is attached to the lower side of the radome by printing or laser direct structuring technology.
[0012] Furthermore, the metasurface array is composed of a plurality of square metasurface patches distributed in a rectangular array.
[0013] Furthermore, the rectangular array formed by the multiple square metasurface patches is divided into several circles of annular arrays according to the distance from the center point of the rectangular array, the size of the square metasurface patches in each circle of the several circles of annular arrays is the same, and the size of the square metasurface patches in the several circles of annular arrays is negatively correlated with the distance between the several circles of annular arrays and the center point of the rectangular array.
[0014] Furthermore, suppose the annular array is divided into N circles from the inside to the outside according to the distance from the center point of the rectangular array, and the distance between the slot feed center of the antenna slot layer and the center of the square metasurface patch in the nth ring array is recorded as Z n , n=1, 2, …, N, the distance between the slot feed center of the antenna slot layer and the center of the annular array is recorded as Z0, and the distance difference between the square metasurface patch in the nth annular array and the square metasurface patch in the n-1th annular array to the slot feed center of the antenna slot layer is recorded as , the phase difference caused by the path difference between the square metasurface patch in the nth ring array and the square metasurface patch in the n-1th ring array is recorded as ;
[0015]
[0016]
[0017] in, It is the distance Z n The angle with the distance Z0, is the wavelength of the antenna signal in free space;
[0018] The position of the center of the square metasurface patch is determined by the above formula, and the phase difference from the gap to different metasurface patches is calculated. Then, the side length of the square metasurface in each circle of the annular array is adjusted to compensate for the phase difference caused by the spatial path difference.
[0019] Furthermore, the antenna cover is made of pps resin or abs plastic.
[0020] Furthermore, the gap between the lower side of the metasurface array and the upper surface of the antenna slot layer is 0.5 mm.
[0021] Furthermore, the ridge waveguide is made by metallization of plastic.
[0022] Compared with the prior art, the present invention has the following advantages and effects: the present invention provides a ridge waveguide antenna with an integrated metasurface, which adopts a ridge waveguide slot antenna for coupling feeding, and the feeding part does not use a dielectric substrate, thereby reducing the dielectric loss of the antenna; the present invention forms a metasurface array on the lower surface by using the antenna cover as a substrate, thereby introducing additional resonance points, broadening the bandwidth of the antenna, and thus reducing the limitation of the antenna size on the bandwidth; the metasurface array is printed on the lower side of the antenna cover, is not affected by the external environment, and improves the service life of the antenna; the overall structure of the present invention is simple, the processing is convenient and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 It is a schematic diagram of a ridge waveguide antenna integrated with a metasurface of the present invention.
[0024] Figure 2 It is an exploded diagram of a ridge waveguide antenna integrated with a metasurface of the present invention.
[0025] Figure 3 It is a schematic diagram of the one-to-two ridge waveguide power divider of the present invention.
[0026] Figure 4 Schematic diagram of the metasurface array of the present invention.
[0027] Figure 5 It is a performance schematic diagram of the one-to-two ridge waveguide power divider of the present invention.
[0028] Figure 6 It is a schematic diagram of the change of the impedance bandwidth S11 of the antenna before and after adding the metasurface of the present invention.
[0029] Figure 7 It is a schematic diagram of the change in antenna gain before and after adding the metasurface of the present invention. DETAILED DESCRIPTION
[0030] In order to elaborate on the technical scheme adopted by the present invention to achieve the predetermined technical purpose, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only partial embodiments of the present invention, rather than all embodiments, and the technical means or technical features in the embodiments of the present invention can be replaced without paying creative work. The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.
[0031] like Figure 1 and Figure 2 As shown, a ridge waveguide antenna with an integrated metasurface of the present invention comprises an antenna cover 1, a metasurface array 2, an antenna slot layer 3 and a ridge waveguide 4, wherein the antenna slot layer 3 is arranged on the upper side of the ridge waveguide 4, the metasurface array 2 is arranged on the lower side of the antenna cover 1, the antenna cover 1 is located above the antenna slot layer 3, there is a gap between the lower side of the metasurface array 2 and the upper surface of the antenna slot layer 3, and the metasurface array 2 is composed of a plurality of metasurface patches distributed in an array to introduce additional resonance points.
[0032] In one embodiment of the present invention, the ridge waveguide 4 adopts a single ridge waveguide antenna unit.
[0033] The antenna slot layer 3 has a rectangular slot etched in the middle of the square copper sheet for radiation, coupling energy to a specific area.
[0034] In another embodiment of the present invention, the ridge waveguide 4 includes two ridge waveguide antenna units, the two ridge waveguide antenna units are arranged symmetrically in the same direction to form an array, and the two ridge waveguide antenna units are respectively connected to the two output ends of the one-to-two ridge waveguide power divider. The metasurface array 2 corresponds to the number of waveguide antenna units of the ridge waveguide, that is, in this embodiment, two groups of metasurface arrays 2 are correspondingly arranged for the two ridge waveguide antenna units, and the positions of the two groups of metasurface arrays 2 correspond to the waveguide antenna units and the corresponding slot positions. The gain of the antenna is improved by the two ridge waveguide antenna units. Figure 5 As shown, the one-to-two ridge waveguide power divider has good performance at an operating frequency of 72.5 GHz-84.5 GHz, with S11 < -20 dB and S21 and S31 close to 3 dB.
[0035] The present invention adopts a ridge waveguide slot antenna for coupling feeding. With this design, the feeding part does not use a dielectric substrate, thereby reducing the feeding loss of the antenna.
[0036] The metasurface array 2 is attached to the lower side of the radome 1 by printing or laser direct structuring (LDS). The metasurface array 2 is printed on the lower side of the radome 1. The attached figure only shows a part of the radome 1. The actual radome 1 completely wraps the entire internal antenna structure, that is, the metasurface array 2 is located inside the radome 1 and is not affected by the external environment, which improves the service life of the antenna.
[0037] The metasurface array 2 is composed of a plurality of square metasurface patches distributed in a rectangular array. In the rectangular array composed of a plurality of square metasurface patches, the array is divided into a plurality of circular arrays according to the distance from the center point of the rectangular array. The size of the square metasurface patches in each of the plurality of circular arrays is the same, and the size of the square metasurface patches in the plurality of circular arrays is negatively correlated with the distance between the plurality of circular arrays and the center point of the rectangular array. The metasurface array 2 can introduce additional resonance points to broaden the bandwidth of the antenna. The matrix structure in which the area gradually decreases from the inside to the outside and the distance gradually increases makes the surface current distribution of the metasurface array 2 more uniform, thereby improving the directivity of the antenna. The bandwidth of the antenna is often limited by its physical size, and the added metasurface array 2 can broaden the bandwidth of the antenna without increasing the physical size of the antenna, thereby reducing the limitation of the antenna size on the bandwidth and broadening the antenna bandwidth.
[0038] Assume that the annular array is divided into N circles from the inside to the outside according to the distance from the center point of the rectangular array. The distance between the slot feed center of the antenna slot layer and the center of the square metasurface patch in the nth ring array is recorded as Z n , n=1, 2, …, N, the distance between the slot feed center of the antenna slot layer and the center of the annular array is recorded as Z0, and the distance difference between the square metasurface patch in the nth annular array and the square metasurface patch in the n-1th annular array to the slot feed center of the antenna slot layer is recorded as , the phase difference caused by the path difference between the square metasurface patch in the nth ring array and the square metasurface patch in the n-1th ring array is recorded as .
[0039]
[0040]
[0041] in, It is the distance Z n The angle with the distance Z0, is the wavelength of the antenna signal in free space.
[0042] The position of the center of the square metasurface patch is determined by the above formula, and the phase difference from the gap to different metasurface patches is calculated. Then, the side length of the square metasurface in each circle of the annular array is adjusted to compensate for the phase difference caused by the spatial path difference.
[0043] The antenna cover 1 is made of PPS resin or ABS plastic and serves as the base of the metasurface array 2 and the outer shield of the entire antenna.
[0044] The gap between the lower side of the metasurface array 2 and the upper surface of the antenna slot layer 3 is 0.5 mm, which greatly reduces the cross-section of the antenna and makes the antenna structure more compact.
[0045] The ridge waveguide 4 is made of plastic metallization, which reduces the weight of the antenna and the processing cost.
[0046] like Figure 6 and Figure 7 As shown, the impedance bandwidth S11 of the antenna is significantly widened by the configuration of the metasurface array 2, and S11 is less than -10dB at a frequency of 73.5GHz-83.5GHz. The gain of the antenna is increased from the original 12dBi to 14.6dBi, and the gain of the antenna is significantly improved.
[0047] The present invention provides a ridge waveguide antenna with integrated metasurface, which adopts a ridge waveguide slot antenna for coupling feeding, and the feeding part does not use a dielectric substrate, thereby reducing the dielectric loss of the antenna; the present invention forms a metasurface array on the lower surface by using the antenna cover as a substrate, thereby introducing additional resonance points, broadening the bandwidth of the antenna, and thus reducing the limitation of the antenna size on the bandwidth; the metasurface array is printed on the lower side of the antenna cover, is not affected by the external environment, and improves the service life of the antenna; the present invention has a simple overall structure, is easy to process and is low in cost.
[0048] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement made to the above embodiments without departing from the content of the technical solution of the present invention, based on the technical essence of the present invention, within the spirit and principles of the present invention, still fall within the protection scope of the technical solution of the present invention.
Claims
1. A ridge waveguide antenna integrated with a metasurface, characterized in that: It comprises an antenna cover, a metasurface array, an antenna slot layer and a ridge waveguide, wherein the antenna slot layer is arranged on the upper side of the ridge waveguide, the metasurface array is arranged on the lower side of the antenna cover, the antenna cover is located above the antenna slot layer, there is a gap between the lower side of the metasurface array and the upper surface of the antenna slot layer, and the metasurface array is composed of a plurality of metasurface patches distributed in an array to introduce additional resonance points; the metasurface array is composed of a plurality of square metasurface patches distributed in a rectangular array; The rectangular array formed by the plurality of square metasurface patches is divided into a plurality of annular arrays according to the distance from the center point of the rectangular array, the size of the square metasurface patches in each of the plurality of annular arrays is the same, and the size of the square metasurface patches in the plurality of annular arrays is negatively correlated with the distance between the plurality of annular arrays and the center point of the rectangular array; Assume that the annular array is divided into N circles from the inside to the outside according to the distance from the center point of the rectangular array. The distance between the slot feed center of the antenna slot layer and the center of the square metasurface patch in the nth ring array is recorded as Z n , n=1, 2, …, N, the distance between the slot feed center of the antenna slot layer and the center of the annular array is recorded as Z0, and the distance difference between the square metasurface patch in the nth annular array and the square metasurface patch in the n-1th annular array to the slot feed center of the antenna slot layer is recorded as , the phase difference caused by the path difference between the square metasurface patch in the nth ring array and the square metasurface patch in the n-1th ring array is recorded as ; , ; in, It is the distance Z n The angle with the distance Z0, is the wavelength of the antenna signal in free space; The position of the center of the square metasurface patch is determined by the above formula, and the phase difference from the gap to different metasurface patches is calculated. Then, the side length of the square metasurface in each circle of the annular array is adjusted to compensate for the phase difference caused by the spatial path difference.
2. The ridge waveguide antenna integrated with a metasurface according to claim 1, characterized in that: The ridge waveguide adopts a single ridge waveguide antenna unit.
3. The ridge waveguide antenna integrated with a metasurface according to claim 1, characterized in that: The ridge waveguide comprises two ridge waveguide antenna units, which are arranged symmetrically in the same direction to form an array, and the two ridge waveguide antenna units are respectively connected to two output ends of a one-to-two ridge waveguide power divider.
4. The ridge waveguide antenna integrated with a metasurface according to claim 1, characterized in that: The metasurface array is attached to the underside of the radome by printing or laser direct structuring technology.
5. The ridge waveguide antenna integrated with a metasurface according to claim 1, characterized in that: The antenna cover is made of pps resin or abs plastic.
6. The ridge waveguide antenna integrated with a metasurface according to claim 1, characterized in that: The gap between the lower side of the metasurface array and the upper surface of the antenna slot layer is 0.5 mm.
7. The ridge waveguide antenna integrated with a metasurface according to claim 1, characterized in that: The ridge waveguide is made by metallizing plastic.