A rectangular waveguide lens-based terahertz two-dimensional multi-beam antenna

Abstract

The application discloses a kind of based on rectangular waveguide lens terahertz two-dimensional multi-beam antenna, including two-dimensional feed array, rectangular metal cavity and rectangular waveguide lens;Two-dimensional feed array includes first metal substrate, first metal substrate is provided with several rectangular waveguide feed units, each rectangular waveguide feed unit is connected with feed port;Rectangular waveguide lens includes second metal substrate, second metal substrate is provided with several rectangular waveguide phase shift units, and the rectangular waveguide phase shift units of adjacent row are mutually staggered distribution.The application is realized two-dimensional multi-beam scanning by the way of two-dimensional feed array bias feed, with the advantages of two-dimensional scanning angle and gain can be arbitrarily designed, large bandwidth advantage.The application adopts rectangular waveguide array to form metal lens, with the advantages of low high-frequency loss, small size;At the same time, through waveguide array staggered and period compression, mirror image grating lobe is eliminated, with the advantages of low grating lobe, large scanning angle.

Description

Technical Field

[0001] This invention relates to the field of terahertz antenna technology, and more particularly to a two-dimensional terahertz multi-beam antenna based on a rectangular waveguide lens. Background Technology

[0002] With the rapid development of wireless communication system technology, the performance requirements for antennas have also increased. Single-function directional antennas are insufficient to meet the diverse needs of modern communication systems. Therefore, multi-beam antennas capable of simultaneously generating multiple independent directional beams are of great significance. Multi-beam antennas can simultaneously possess high gain and a large scanning angle, which is crucial for improving the operating range and coverage of radio frequency systems. Especially in high-frequency bands such as millimeter waves and terahertz waves, where traditional PIN switches and varactor diodes suffer from high high-frequency losses, high costs, and integration difficulties, multi-beam antennas offer a low-cost, high-performance beam scanning solution. Based on these technological advantages, multi-beam antennas have great application prospects in modern wireless communication systems, including base stations and user terminals, and low-Earth orbit satellite networks.

[0003] Current millimeter-wave / terahertz multibeam antennas are mainly implemented based on reflectors, lenses, beamforming matrices, and phased arrays. Among them, reflective multibeam antennas are simple to design, but require extremely high processing precision and are costly, and suffer from problems such as feed smothering and small scanning angles. Matrix multibeam antennas have large beam scanning angles and good beam performance, but require the integration of phase shifters, couplers, etc., resulting in a large size. Phased array multibeam antennas require the integration of semiconductor devices (varactor diodes, switches), which have poor performance, and high-frequency phased arrays are expensive and complex to design. Lens multibeam antennas have large beam scanning angles, good beam directivity, small size, and no feed smothering problems.

[0004] Based on the advantages of lens-type multi-beam antennas, current domestic and international research mainly utilizes Luneburg lenses, fisheye lenses, and Rotman lenses to achieve multi-beam capabilities. However, due to limitations such as the difficulty in fabricating complex dielectric lenses and high high-frequency transmission loss, current lens-type multi-beam antennas still suffer from problems such as small scanning angles for achieving two-dimensional multi-beam lenses, high manufacturing costs, large size, inability to integrate the feed and lens into a single unit, and high dielectric loss. Therefore, addressing these issues, it is of great significance to propose a low-loss millimeter-wave / terahertz two-dimensional multi-beam antenna with a large two-dimensional scanning angle, low cost, and small size. Summary of the Invention

[0005] To address the aforementioned shortcomings of existing technologies, this invention provides a terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens. By changing the feed position, it can achieve a large-scale scanning of the terahertz beam direction in a two-dimensional plane, offering advantages such as easy fabrication, large operating bandwidth, compact size, and large scanning range.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0007] A terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens is provided, comprising a two-dimensional feed array, a rectangular metal cavity, and a rectangular waveguide lens that are fixedly connected in sequence; the two-dimensional feed array includes a first metal substrate, on which a plurality of rectangular waveguide feed elements are disposed, and the plurality of rectangular waveguide feed elements form a rectangular waveguide feed array; the rectangular waveguide lens includes a second metal substrate, on which a plurality of rectangular waveguide phase-shifting elements are disposed, and the plurality of rectangular waveguide phase-shifting elements form a rectangular waveguide phase-shifting array, with adjacent rows of rectangular waveguide phase-shifting elements staggered from each other; both the rectangular waveguide feed elements and the rectangular waveguide phase-shifting elements are rectangular apertures.

[0008] Furthermore, the thickness of the first metal substrate is equal to the length of the rectangular waveguide feed unit, the width of the first metal substrate is greater than the sum of the widths of all rectangular waveguide feed units in the same row, the height of the first metal substrate is greater than the sum of the heights of all rectangular waveguide feed units in the same column, the horizontal and vertical arrangement periods of the rectangular waveguide feed units in the rectangular waveguide feed array are the same, and the horizontal arrangement period of the rectangular waveguide feed units is greater than the width of the rectangular waveguide feed units.

[0009] Furthermore, the outer height of the rectangular metal cavity is equal to the height of the first metal substrate, and the outer width of the rectangular metal cavity is equal to the width of the first metal substrate.

[0010] Furthermore, the thickness of the second metal substrate is equal to the length of the rectangular waveguide phase shifting unit, the height of the second metal substrate is greater than the sum of the heights of the rectangular waveguide phase shifting units, and the width of the second metal substrate is greater than the sum of the widths of all rectangular waveguide phase shifting units in the same row; the height of the second metal substrate is equal to the height of all first metal substrates in the same column, and the width of the second metal substrate is equal to the width of the first metal substrate.

[0011] Furthermore, all rectangular waveguide phase shifting units have the same height; all rectangular waveguide phase shifting units have the same length; and all rectangular waveguide phase shifting units have slightly different widths.

[0012] Furthermore, the width of the rectangular waveguide phase shifting unit is smaller than the lateral arrangement period of the rectangular waveguide phase shifting unit; the height of the rectangular waveguide phase shifting unit is smaller than the longitudinal arrangement period of the rectangular waveguide phase shifting unit.

[0013] Furthermore, the two-dimensional feed array, the rectangular metal cavity, and the rectangular waveguide lens are all made of aluminum, copper, silver, nickel, or gold.

[0014] Furthermore, the phase shift φ of the rectangular waveguide phase shifting unit ij Satisfying the formula:

[0015]

[0016] Where λ0 is the operating wavelength corresponding to the antenna center operating frequency, the center position of the rectangular waveguide lens is the origin of the coordinate system, (x0, y0, z0) are the coordinates of the center position of the two-dimensional feed array, and z0 is the length of the rectangular metal cavity. ij ,y ij ,0) represents the coordinates of the rectangular waveguide phase-shifting element in the i-th row and j-th column.

[0017] Furthermore, the width w of the rectangular waveguide phase-shifting unit ij Satisfying the formula:

[0018]

[0019] Where L is the length of the rectangular waveguide phase-shifting unit, a is the width of the rectangular waveguide feed unit, and φ ij Let be the phase shift amount of the rectangular waveguide phase shifting element in the i-th row and j-th column.

[0020] The beneficial effects of this invention are as follows:

[0021] This invention achieves two-dimensional multi-beam scanning by using a two-dimensional feed array for offset feeding, which has the advantages of arbitrary design of two-dimensional scanning angle and antenna gain, and large operating bandwidth.

[0022] This invention uses a rectangular waveguide array to form a metal lens, which has the advantages of low high-frequency loss and small size; at the same time, the mirror grating lobe is eliminated by waveguide array misalignment and periodic compression, which has the advantages of low grating lobe and large scanning angle.

[0023] This invention adopts an all-metal structure, which has the advantages of easy processing, small size, and integrated power supply and lens design. Attached Figure Description

[0024] Figure 1 This is a schematic diagram showing the overall structure of the terahertz two-dimensional multi-beam antenna of the present invention.

[0025] Figure 2 This is a schematic diagram of the rectangular waveguide lens structure of the present invention;

[0026] Figure 3 This is the transverse beam scanning pattern of the present invention at 150 GHz;

[0027] Figure 4 This is the longitudinal beam scanning pattern of the present invention at 150 GHz;

[0028] The symbols for the main components in the diagram are explained below:

[0029] 1. Two-dimensional feed array; 101. First metal substrate; 102. Rectangular waveguide feed unit; 2. Rectangular metal cavity; 3. Rectangular waveguide lens; 301. Second metal substrate; 302. Rectangular waveguide phase shifting unit. Detailed Implementation

[0030] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0031] like Figure 1 As shown, the terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens includes a two-dimensional feed array 1, a rectangular metal cavity 2, and a rectangular waveguide lens 3, which are fixedly connected in sequence. The materials of the two-dimensional feed array 1, the rectangular metal cavity 2, and the rectangular waveguide lens 3 are preferably one of aluminum, copper, silver, nickel, and gold. Specifically, during operation, the terahertz wave propagates in the -Z direction. The terahertz wave radiated from the two-dimensional feed array 1 passes through the rectangular metal cavity 2 and enters the rectangular waveguide lens 3. By precisely configuring the width of each waveguide element in the rectangular waveguide lens 3, focusing and angle shifting of the terahertz wave incident at any port in the two-dimensional feed array 1 can be achieved. By switching the ports in the two-dimensional feed array 1, high-gain, large-angle two-dimensional beam scanning of the terahertz wave can be realized. In this embodiment, the center operating frequency f of the terahertz two-dimensional multi-beam antenna is 150 GHz, the operating wavelength λ0 is 2 mm, the focal length F of the rectangular waveguide lens 3 is 6 mm, this frequency belongs to the D band, and the corresponding rectangular waveguide feed unit 102 has a height of 0.83 mm and a width of 1.65 mm.

[0032] The two-dimensional feed array 1 includes a first metal substrate 101, on which a plurality of rectangular waveguide feed units 102 are disposed. Each rectangular waveguide feed unit 102 is a rectangular aperture, and the plurality of rectangular waveguide feed units 102 form a rectangular waveguide feed array. Each rectangular waveguide feed unit 102 serves as a feed port. The thickness of the first metal substrate 101 is equal to the thickness of the rectangular waveguide feed units 102, the width of the first metal substrate 101 is greater than the sum of the widths of all rectangular waveguide feed units 102 in the same row, and the height of the first metal substrate 101 is greater than the sum of the heights of all rectangular waveguide feed units 102 in the same column. The rectangular waveguide feed units 102 in the rectangular waveguide feed array have the same horizontal and vertical arrangement period, and the horizontal arrangement period of the rectangular waveguide feed units 102 is greater than the width of the rectangular waveguide feed units 102. In this embodiment, the thickness (Z direction), width (X direction), and height (Y direction) of the first metal substrate 101 are 2 mm, 16.83 mm, and 13.8 mm, respectively. The rectangular waveguide feed array is preferably configured as 7 rows and 7 columns, with each rectangular waveguide feed unit 102 connected to 7*7 feed ports. The length (Z direction), width, and height of each rectangular waveguide feed unit 102 are preferably 2 mm, 1.65 mm, and 0.83 mm, respectively. The horizontal (X direction) array period of the rectangular waveguide feed array 102 is preferably 2 mm; the vertical (Y direction) array period is preferably 2 mm.

[0033] The length of the rectangular metal cavity 2 is equal to the focal length of the rectangular waveguide lens 3. The external height of the rectangular metal cavity 2 is equal to the height of the first metal substrate 101, and the external width of the rectangular metal cavity 2 is equal to the width of the first metal substrate 101. The metal thickness of the rectangular metal cavity 3 should be as small as possible. In this embodiment, the length (Z direction), width, and height of the cavity in the rectangular metal cavity 2 are preferably 6 mm, 15.65 mm, and 13.4 mm, respectively. The length (Z direction), width, and height of the metal shell in the rectangular metal cavity 2 are preferably 6 mm, 16.83 mm, and 13.8 mm, respectively.

[0034] like Figure 2As shown, the rectangular waveguide lens 3 includes a second metal substrate 301, on which a plurality of rectangular waveguide phase-shifting units 302 are disposed. Each rectangular waveguide phase-shifting unit 302 is a rectangular aperture. The plurality of rectangular waveguide phase-shifting units 302 form a rectangular waveguide phase-shifting array, with adjacent rows of rectangular waveguide phase-shifting units 302 staggered. The thickness of the second metal substrate 301 is equal to the length of each rectangular waveguide phase-shifting unit 302. The height of the second metal substrate 301 is greater than the sum of the heights of all rectangular waveguide phase-shifting units 302 in the same column. The width of the second metal substrate 301 is greater than the sum of the widths of all rectangular waveguide phase-shifting units 302 in the same row. The height of the second metal substrate 301 is equal to the height of the first metal substrate 101, and the width of the second metal substrate 301 is equal to the width of the first metal substrate 101.

[0035] All rectangular waveguide phase shifting units 302 have the same narrow side length. While all rectangular waveguide phase shifting units 302 have the same length, the narrow side lengths of all rectangular waveguide phase shifting units 302 are not entirely identical. The width of the rectangular waveguide phase shifting unit 302 can be precisely calculated using a formula, and different widths achieve different phase shift amounts.

[0036] The lateral arrangement period of the rectangular waveguide phase shifting unit 302 is one time the operating wavelength of the antenna; the longitudinal arrangement period of the rectangular waveguide phase shifting unit 302 is one-quarter of the operating wavelength of the antenna; the width of the rectangular waveguide phase shifting unit 302 is less than the lateral arrangement period of the rectangular waveguide phase shifting unit; the height of the rectangular waveguide phase shifting unit 302 is less than the longitudinal arrangement period of the rectangular waveguide phase shifting unit.

[0037] In this embodiment, the thickness, width, and height of the second metal substrate 301 are preferably 8 mm, 16.83 mm, and 13.8 mm, respectively. The rectangular waveguide phase-shifting array includes 27 rows of units, with 7 units in odd-numbered rows and 8 units in even-numbered rows, for a total of 202 units. The length (Z direction) L of each unit is preferably 8 mm, and the height is preferably 0.4 mm. The longitudinal array period of the rectangular waveguide phase-shifting array is preferably λ0 / 4 = 0.5 mm, and the transverse array period is preferably λ0 = 2 mm, wherein the odd-numbered rows and even-numbered rows are staggered by λ0 / 2 = 1 mm. The optimal unit arrangement of the rectangular waveguide lens 3 is as follows: the longitudinal arrangement period is 1 / 4 of the working wavelength of the terahertz wave; the transverse arrangement period is 1 times the working wavelength of the terahertz wave, and the odd-numbered rows and even-numbered rows are staggered by 1 / 2 times the working wavelength in the narrow side direction.

[0038] Phase shift φ of rectangular waveguide phase shifting unit 302 ij satisfy:

[0039]

[0040] In the formula, λ0 = 2mm is the working wavelength corresponding to the center working frequency. When the center position of the rectangular waveguide lens 3 is taken as the origin of the coordinate system, (x0, y0, z0) are the coordinates of the center position of the two-dimensional feed array 1, and z0 = 6mm is the length of the rectangular metal cavity 2. ij ,y ij ,0) represents the coordinates of the rectangular waveguide phase-shifting element 302 in the i-th row and j-th column.

[0041] The width w of the rectangular waveguide phase shifting unit 302 ij satisfy:

[0042]

[0043] In the formula, L is the thickness of the rectangular waveguide lens, a is the width of the standard rectangular waveguide, and φ is the thickness of the rectangular waveguide lens. ij Let be the phase shift amount of the rectangular waveguide phase shifting unit 302 in the i-th row and j-th column.

[0044] Figure 1 and Figure 2 In the diagram, the positive X-axis direction is the height direction of the rectangular metal cavity 2, the positive Y-axis direction is the width direction of the rectangular metal cavity 2, and the positive Z-axis direction is the opposite direction of terahertz wave propagation during operation.

[0045] Using CST 3D electromagnetic field simulation software, a terahertz 2D multi-beam antenna was modeled and simulated. The calculation results were then obtained. Figure 3 The simulation results of the lateral beam scanning of the terahertz two-dimensional multi-beam antenna when switching between ports 41 and 47 are shown. With the beam pointing at phi = 0°, the beam pointing at ports 41 and 47 is theta = 136 / 224° with a beam gain of 19 dBi; the beam pointing at ports 42 and 46 is theta = 151 / 209° with a beam gain of 21.6 dBi; the beam pointing at ports 43 and 45 is theta = 168 / 192° with a beam gain of 23.8 dBi; and the beam pointing at port 44 is theta = 180° with a beam gain of 23.7 dBi. Port 44 represents the rectangular waveguide feed element 102 corresponding to the 4th row and 4th column.

[0046] like Figure 4The simulation results of longitudinal beam scanning of the terahertz two-dimensional multi-beam antenna when switching between ports 14 and 74 are shown. The beam pointing is at phi = 90°. The beam pointing at ports 14 and 74 is theta = 130 / 230° with a beam gain of 18.9 dBi; the beam pointing at ports 24 and 64 is theta = 155 / 205° with a beam gain of 21.3 dBi; the beam pointing at ports 34 and 54 is theta = 167 / 193° with a beam gain of 22.4 dBi; and the beam pointing at port 44 is theta = 180° with a beam gain of 23.7 dBi.

[0047] The aforementioned terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens achieves a two-dimensional beam scanning range of ±50×±44° by changing the feed port. The average gain is 21.78 dBi during transverse beam scanning and 21.27 dBi during longitudinal beam scanning. The overall dimensions (length×width×height) are 16mm×16.83mm×13.8mm. This terahertz two-dimensional multi-beam antenna has the advantages of a large two-dimensional beam scanning range, high gain, and small size, and is of great value in terahertz communication, radar, and imaging applications.

[0048] For those skilled in the art, the present invention is not limited to the details of the exemplary embodiments described above, and the invention can be implemented in other specific forms without departing from its essential characteristics. Therefore, the embodiments should be considered exemplary and not restrictive. The scope of the invention is defined by the appended claims rather than the foregoing description, and therefore all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0049] Furthermore, although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens, characterized in that, It includes a two-dimensional feed array (1), a rectangular metal cavity (2), and a rectangular waveguide lens (3) that are fixedly connected in sequence. The two-dimensional feed array (1) includes a first metal substrate (101), on which a plurality of rectangular waveguide feed units (102) are disposed, and the plurality of rectangular waveguide feed units (102) form a rectangular waveguide feed array. The rectangular waveguide lens (3) includes a second metal substrate (301), on which a plurality of rectangular waveguide phase shifting units (302) are disposed. The plurality of rectangular waveguide phase shifting units (302) form a rectangular waveguide phase shifting array, and the rectangular waveguide phase shifting units (302) in adjacent rows are staggered. The rectangular waveguide feeding unit (102) and the rectangular waveguide phase shifting unit (302) are both rectangular holes.

2. The terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens according to claim 1, characterized in that, The thickness of the first metal substrate (101) is equal to the length of the rectangular waveguide feed unit (102). The width of the first metal substrate (101) is greater than the sum of the widths of all rectangular waveguide feed units (102) in the same row. The height of the first metal substrate (101) is greater than the sum of the heights of all rectangular waveguide feed units (102) in the same column. The horizontal and vertical arrangement periods of the rectangular waveguide feed units (102) in the rectangular waveguide feed array are the same. The horizontal arrangement period of the rectangular waveguide feed units (102) is greater than the width of the rectangular waveguide feed units (102).

3. The terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens according to claim 1, characterized in that, The external height of the rectangular metal cavity (2) is equal to the height of the first metal substrate (101), and the external width of the rectangular metal cavity (2) is equal to the width of the first metal substrate (101).

4. The terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens according to claim 1, characterized in that, The thickness of the second metal substrate (301) is equal to the length of the rectangular waveguide phase shifting unit (302), the height of the second metal substrate (301) is greater than the sum of the heights of all rectangular waveguide phase shifting units (302) in the same column, and the width of the second metal substrate (301) is greater than the sum of the widths of all rectangular waveguide phase shifting units (302) in the same row; the height of the second metal substrate (301) is equal to the height of the first metal substrate (101), and the width of the second metal substrate (301) is equal to the width of the first metal substrate (101).

5. The terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens according to claim 1, characterized in that, All the rectangular waveguide phase shifting units (302) have the same height; all the rectangular waveguide phase shifting units (302) have the same length; and the widths of all the rectangular waveguide phase shifting units (302) are not exactly the same.

6. The terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens according to claim 1, characterized in that, The width of the rectangular waveguide phase shifting unit (302) is less than the lateral arrangement period of the rectangular waveguide phase shifting unit (302); the height of the rectangular waveguide phase shifting unit (302) is less than the longitudinal arrangement period of the rectangular waveguide phase shifting unit (302).

7. The terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens according to claim 1, characterized in that, The materials of the two-dimensional feed array (1), the rectangular metal cavity (2), and the rectangular waveguide lens (3) are all aluminum, copper, silver, nickel, or gold.

8. The terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens according to claim 1, characterized in that, The phase shift amount of the rectangular waveguide phase shifting unit (302) Satisfying the formula: ； in, The working wavelength corresponds to the center working frequency of the antenna. The center position of the rectangular waveguide lens (3) is the origin of the coordinate system. The coordinates of the center position of the two-dimensional feed array (1) are given. The length of the rectangular metal cavity (2) is given. For the first Line number The coordinates of the rectangular waveguide phase shifting unit (302).

9. The terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens according to claim 8, characterized in that, The width of the rectangular waveguide phase shifting unit (302) Satisfying the formula: ； in, L The length of the rectangular waveguide phase shifting unit (302) is... The width of the rectangular waveguide feed element (102) is given. For the first Line number Phase shift amount of the rectangular waveguide phase shifting unit (302).

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