Terahertz two-dimensional multi-beam antenna based on rectangular waveguide lens

Abstract

The invention discloses a terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens. The terahertz two-dimensional multi-beam antenna comprises a two-dimensional feed array, a rectangular metal cavity and the rectangular waveguide lens, the two-dimensional feed array comprises a first metal substrate, a plurality of rectangular waveguide feed units are arranged on the first metal substrate, and each rectangular waveguide feed unit is connected with a feed port; the rectangular waveguide lens comprises a second metal substrate, a plurality of rectangular waveguide phase shifting units are arranged on the second metal substrate, and the rectangular waveguide phase shifting units in adjacent rows are distributed in a staggered mode. According to the invention, two-dimensional multi-beam scanning is realized in an offset feed mode through the two-dimensional feed array, and the antenna has the advantages that the two-dimensional scanning angle and gain can be designed at will, and the working bandwidth is large. The rectangular waveguide array is adopted to form the metal lens, and the advantages of low high-frequency loss and small size are achieved; meanwhile, mirror image grating lobes are eliminated through waveguide array dislocation and periodic compression, and the advantages of low grating lobe and large scanning angle are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of terahertz antennas, and in particular to a terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens. Background Art

[0002] With the rapid development of wireless communication system technology, the performance requirements for antennas have also increased. Directional antennas with a single function are difficult to meet the diverse requirements of modern communication systems, so multi-beam antennas that can generate multiple independent directional beams at the same time are of great significance. Multi-beam antennas can have high gain and large scanning angles at the same time, which is of great significance for improving the range and coverage of radio frequency systems; especially in high-frequency bands such as millimeter waves / terahertz, due to the high high-frequency loss, high cost, and difficulty in integration of traditional PIN switches and varactor diodes, multi-beam antennas are a low-cost, high-performance beam scanning solution. Based on these technical advantages, multi-beam antennas have great application prospects in base stations and user terminals in modern wireless communication systems, low-orbit satellite networks, and other fields.

[0003] Current millimeter-wave / terahertz multi-beam antennas are mainly implemented based on reflecting surfaces, lenses, beam-forming matrices and phased arrays. Among them, the reflective multi-beam antenna is simple in design, but requires extremely high processing precision and high cost, and has problems such as feed source obstruction and small scanning angle; the matrix multi-beam antenna has a large beam scanning angle and good beam performance, but requires the integration of phase shifters, couplers, etc., resulting in a large size; the phased array multi-beam antenna requires the integration of semiconductor devices (varactors, switches) with poor performance, and the high-frequency phased array is expensive and complex in design; the lens-type multi-beam antenna has a large beam scanning angle, good beam directivity, a small size, and no feed source obstruction problem.

[0004] Based on the advantages of lens-type multi-beam antennas, the multi-beam capability is currently mainly achieved through Luneburg lenses, fisheye lenses, and Rotman lenses at home and abroad. However, due to the difficulty in processing complex dielectric lenses and large high-frequency transmission losses, the current lens-type multi-beam antennas still have problems such as small scanning angle of the two-dimensional multi-beam lens, high processing cost, large volume, inability to integrate the feed and lens, and large dielectric loss. Therefore, in response to the above problems, it is necessary to propose a low-loss millimeter-wave / terahertz two-dimensional multi-beam antenna with a large two-dimensional scanning angle, low cost, and small volume, which is of great significance. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens. By changing the feeding position, the terahertz beam direction can be scanned over a large range in a two-dimensional plane. It has the advantages of easy processing, large working bandwidth, compact size and large scanning range.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0007] Provided is a terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens, comprising a two-dimensional feeding array, a rectangular metal cavity and a rectangular waveguide lens which are fixedly connected in sequence; the two-dimensional feeding array comprises a first metal substrate, on which a plurality of rectangular waveguide feeding units are arranged, and the plurality of rectangular waveguide feeding units form a rectangular waveguide feeding array; the rectangular waveguide lens comprises a second metal substrate, on which a plurality of rectangular waveguide phase shifting units are arranged, and the plurality of rectangular waveguide phase shifting units form a rectangular waveguide phase shifting array, and the rectangular waveguide phase shifting units in adjacent rows are staggered and distributed; the rectangular waveguide feeding units and the rectangular waveguide phase shifting units are both rectangular holes.

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

[0009] Further, 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 shift unit, the height of the second metal substrate is greater than the sum of the heights of the rectangular waveguide phase shift units, and the width of the second metal substrate is greater than the sum of the widths of all the rectangular waveguide phase shift units in the same row; the height of the second metal substrate is equal to the height of all the 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 shift units have the same height; all rectangular waveguide phase shift units have the same length, and all rectangular waveguide phase shift units have different widths.

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

[0013] Furthermore, the two-dimensional feeding 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 amount φ of the rectangular waveguide phase shift unit ij Satisfy the formula:

[0015]

[0016] Among them, λ0 is the working wavelength corresponding to the central working frequency of the antenna, the center position of the rectangular waveguide lens is the coordinate origin, (x0, y0, z0) is the coordinate of the center position of the two-dimensional feeding array, z0 is the length of the rectangular metal cavity, (x ij ,y ij ,0) is the coordinate of the rectangular waveguide phase shift unit in the i-th row and j-th column.

[0017] Furthermore, the width w of the rectangular waveguide phase shift unit is ij Satisfy the formula:

[0018]

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

[0020] The beneficial effects of the present invention are:

[0021] The present invention realizes two-dimensional multi-beam scanning by means of offset feeding through a two-dimensional feeding array, and has the advantages that the two-dimensional scanning angle and antenna gain can be arbitrarily designed and the working bandwidth is large.

[0022] The present invention adopts 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 image grating lobe is eliminated through the waveguide array dislocation and period compression, and has the advantages of low grating lobe and large scanning angle.

[0023] The present invention adopts an all-metal structure and has the advantages of easy processing, small size, and integrated design of feed and lens. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

[0028] The main components in the figure are described as follows:

[0029] 1. Two-dimensional feeding array; 101. First metal substrate; 102. Rectangular waveguide feeding unit; 2. Rectangular metal cavity; 3. Rectangular waveguide lens; 301. Second metal substrate; 302. Rectangular waveguide phase shift unit. DETAILED DESCRIPTION

[0030] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0031] like Figure 1 As shown, the terahertz two-dimensional multi-beam antenna based on the 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 propagation direction of the terahertz wave is the -Z direction. The terahertz wave radiated from the two-dimensional feed array 1 enters the rectangular waveguide lens 3 through the rectangular metal cavity 2. By accurately configuring the width of each waveguide unit in the rectangular waveguide lens 3, the terahertz wave incident from any port in the two-dimensional feed array 1 can be focused and angle-shifted. By switching the ports in the two-dimensional feed array 1, high-gain and large-angle two-dimensional beam scanning of the terahertz wave can be achieved. In this embodiment, the central 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, the frequency belongs to the D band, and the corresponding rectangular waveguide feeding unit 102 has a height of 0.83 mm and a width of 1.65 mm.

[0032] The two-dimensional feeding array 1 comprises a first metal substrate 101, on which a plurality of rectangular waveguide feeding units 102 are arranged, the rectangular waveguide feeding units 102 are rectangular holes, and the plurality of rectangular waveguide feeding units 102 form a rectangular waveguide feeding array, and each rectangular waveguide feeding unit 102 serves as a feeding port. The thickness of the first metal substrate 101 is equal to the thickness of the rectangular waveguide feeding unit 102, the width of the first metal substrate 101 is greater than the sum of the widths of all the rectangular waveguide feeding 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 the rectangular waveguide feeding units 102 in the same column. The lateral and longitudinal arrangement periods of the rectangular waveguide feeding units 102 in the rectangular waveguide feeding array are the same, and the lateral arrangement period of the rectangular waveguide feeding units 102 is greater than the width of the rectangular waveguide feeding 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 feeding array is preferably set to 7 rows and 7 columns, and the number of feeding ports corresponding to the rectangular waveguide feeding unit 102 is 7*7, and the length (Z direction), width and height of each rectangular waveguide feeding unit 102 are preferably 2 mm, 1.65 mm, and 0.83 mm, respectively. The transverse (X direction) array period of the rectangular waveguide feeding array 102 is preferably 2 mm; the longitudinal (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 outer height of the rectangular metal cavity 2 is equal to the height of the first metal substrate 101, and the outer 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 shift units 302 are arranged. The rectangular waveguide phase shift units 302 are rectangular holes. The plurality of rectangular waveguide phase shift units 302 form a rectangular waveguide phase shift array, and the rectangular waveguide phase shift units 302 in adjacent rows are staggered. The thickness of the second metal substrate 301 is equal to the length of the rectangular waveguide phase shift unit 302, the height of the second metal substrate 301 is greater than the sum of the heights of all the rectangular waveguide phase shift 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 the rectangular waveguide phase shift 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] The narrow sides of all rectangular waveguide phase shift units 302 are the same length. The narrow sides of all rectangular waveguide phase shift units 302 are not exactly the same length. The width of the rectangular waveguide phase shift unit 302 can be accurately calculated by a formula, and different widths achieve different phase shift amounts.

[0036] The lateral arrangement period of the rectangular waveguide phase shift unit 302 is one times the working wavelength of the antenna; the longitudinal arrangement period of the rectangular waveguide phase shift unit 302 is one quarter of the working wavelength of the antenna; the width of the rectangular waveguide phase shift unit 302 is smaller than the lateral arrangement period of the rectangular waveguide phase shift unit; the height of the rectangular waveguide phase shift unit 302 is smaller than the longitudinal arrangement period of the rectangular waveguide phase shift 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-shift array includes 27 rows of units, the number of units in the odd rows is 7, the number of units in the even rows is 8, and there are 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-shift array is preferably λ0 / 4=0.5 mm, and the transverse array period is preferably λ0=2 mm, wherein the odd rows and even rows are staggered by λ0 / 2=1 mm. The optimal unit arrangement of the rectangular waveguide lens 3 is: 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 rows and even rows in the narrow side direction are staggered by 1 / 2 times the working wavelength.

[0038] The phase shift amount φ of the rectangular waveguide phase shift unit 302 ij satisfy:

[0039]

[0040] Wherein, λ0=2mm is the working wavelength corresponding to the central working frequency, when the center position of the rectangular waveguide lens 3 is taken as the coordinate origin, (x0, y0, z0) is the coordinate of the center position of the two-dimensional feeding array 1, z0=6mm is the length of the rectangular metal cavity 2, (x ij ,y ij ,0) is the coordinate of the rectangular waveguide phase shift unit 302 in the i-th row and j-th column.

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

[0042]

[0043] Where L is the thickness of the rectangular waveguide lens, a is the length of the wide side of the standard rectangular waveguide, φ ij is the phase shift amount of the rectangular waveguide phase shift unit 302 in the i-th row and j-th column.

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

[0045] The CST three-dimensional electromagnetic field simulation software is used to model and simulate the terahertz two-dimensional multi-beam antenna. According to the calculation results, Figure 3 The lateral beam scanning simulation results of the terahertz two-dimensional multi-beam antenna when switching between ports 41 to 47 are shown. The beam pointing is at phi = 0°, the beam pointing of ports 41 and 47 is theta = 136 / 224°, and the beam gain is 19dBi; the beam pointing of ports 42 and 46 is theta = 151 / 209°, and the beam gain is 21.6dBi; the beam pointing of ports 43 and 45 is theta = 168 / 192°, and the beam gain is 23.8dBi; the beam pointing of port 44 is theta = 180°, and the beam gain is 23.7dBi. Port 44 represents the rectangular waveguide feeding unit 102 corresponding to the 4th row and the 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 of ports 14 and 74 is theta=130 / 230°, and the beam gain is 18.9dBi; the beam pointing of ports 24 and 64 is theta=155 / 205°, and the beam gain is 21.3dBi; the beam pointing of ports 34 and 54 is theta=167 / 193°, and the beam gain is 22.4dBi; the beam pointing of port 44 is theta=180°, and the beam gain is 23.7dBi.

[0047] The above-mentioned terahertz two-dimensional multi-beam antenna based on rectangular waveguide lens realizes a two-dimensional beam scanning range of ±50×±44° by changing the feeding port. The average gain during lateral beam scanning is 21.78dBi; the average gain during longitudinal beam scanning is 21.27dBi; the overall size (length×width×height) is: 16mm×16.83mm×13.8mm; the terahertz two-dimensional multi-beam antenna has the advantages of 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 other persons skilled in the art, the present invention is not limited to the details of the exemplary embodiments described above, and the present invention can be implemented in other specific forms without departing from the basic characteristics of the present invention. Therefore, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any reference numerals in the claims should not be regarded as limiting the claims involved.

[0049] In addition, although this specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes 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 comprises a two-dimensional feeding array (1), a rectangular metal cavity (2) and a rectangular waveguide lens (3) which are fixedly connected in sequence; The two-dimensional feeding array (1) comprises a first metal substrate (101), a plurality of rectangular waveguide feeding units (102) are arranged on the first metal substrate (101), and the plurality of rectangular waveguide feeding units (102) form a rectangular waveguide feeding array; The rectangular waveguide lens (3) comprises a second metal substrate (301), on which a plurality of rectangular waveguide phase shift units (302) are arranged, the plurality of rectangular waveguide phase shift units (302) forming a rectangular waveguide phase shift array, and the rectangular waveguide phase shift units (302) in adjacent rows are staggered and distributed; the rectangular waveguide feeding unit (102) and the rectangular waveguide phase shift 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 feeding unit (102), the width of the first metal substrate (101) is greater than the sum of the widths of all the rectangular waveguide feeding units (102) in the same row, the height of the first metal substrate (101) is greater than the sum of the heights of all the rectangular waveguide feeding units (102) in the same column, the lateral and longitudinal arrangement periods of the rectangular waveguide feeding units (102) in the rectangular waveguide feeding array are the same, and the lateral arrangement period of the rectangular waveguide feeding units (102) is greater than the width of the rectangular waveguide feeding units (102).

3. The terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens according to claim 1, characterized in that: The outer height of the rectangular metal cavity (2) is equal to the height of the first metal substrate (101), and the outer 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 shift unit (302); the height of the second metal substrate (301) is greater than the sum of the heights of all the rectangular waveguide phase shift units (302) in the same column; the width of the second metal substrate (301) is greater than the sum of the widths of all the rectangular waveguide phase shift 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 shift units (302) have the same height; all the rectangular waveguide phase shift units (302) have the same length; and all the rectangular waveguide phase shift units (302) have different widths.

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 shift unit (302) is smaller than the transverse arrangement period of the rectangular waveguide phase shift unit (302); and the height of the rectangular waveguide phase shift unit (302) is smaller than the longitudinal arrangement period of the rectangular waveguide phase shift unit (302).

7. The terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens according to claim 1, characterized in that: The two-dimensional feeding array (1), the rectangular metal cavity (2), and the rectangular waveguide lens (3) are all made of 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 φ of the rectangular waveguide phase shift unit (302) ij Satisfy the formula: Wherein, λ0 is the working wavelength corresponding to the central working frequency of the antenna, the center position of the rectangular waveguide lens (3) is the coordinate origin, (x0, y0, z0) are the coordinates of the center position of the two-dimensional feeding array (1), z0 is the length of the rectangular metal cavity (2), (x ij ,y ij ,0) is the coordinate of the rectangular waveguide phase shift unit (302) in the i-th row and j-th column.

9. The terahertz two-dimensional multi-beam antenna based on a rectangular waveguide lens according to claim 8, characterized in that: The width w of the rectangular waveguide phase shift unit (302) is ij Satisfy the formula: Wherein, L is the length of the rectangular waveguide phase shift unit (302), a is the width of the rectangular waveguide feeding unit (102), φ ij is the phase shift amount of the rectangular waveguide phase shift unit (302) in the i-th row and j-th column.

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