A terahertz multi-beam frequency-scanning antenna based on dielectric lens

Abstract

The present invention discloses a terahertz multi-beam frequency-scanning antenna based on a dielectric lens, comprising: a feed array comprising a metal substrate and a rectangular waveguide feed array provided on the metal substrate; a right-angled trapezoidal metal cavity comprising a right-angled waist side and an oblique waist side; a frequency-shifted dielectric lens comprising a dielectric substrate and a dielectric shaping lens located above the dielectric substrate; the dielectric shaping lens comprising N*M shaping units distributed transversely and longitudinally along the dielectric substrate, each shaping unit having equal length and width, and the height of each shaping unit being specifically calculated. The present invention integrates the feed array and the frequency-shifted dielectric lens to achieve the fusion of time-domain beam scanning and frequency-domain beam scanning, and has the advantages of time-frequency fusion two-dimensional scanning and high beam resolution; and by using the frequency-shifted dielectric lens to achieve the offset and radiation end, it has the advantages of arbitrary gain expansion, no grating lobes, and a large operating bandwidth.

Description

Technical Field

[0001] The present invention relates to the field of terahertz antennas, and in particular to a terahertz multi-beam frequency-sweeping antenna based on a dielectric lens. Background Art

[0002] In RF integrated systems, achieving functions such as dynamic communication, point cloud imaging, and scanning radar often requires comprehensive scanning of the target area. Therefore, antennas with beam scanning capabilities have important application value. Traditional beam scanning antennas are often implemented using electronically controlled phased arrays or mechanically scanned antennas. Electronically controlled phased arrays require the integration of thousands of antenna elements and tuning devices, which is not only costly and difficult to integrate, but also suffers from high heat dissipation and complex beam control. Furthermore, in high-frequency bands such as millimeter waves and terahertz, due to the immaturity of high-frequency varactor diodes and PIN switch technology, terahertz phased arrays are far from practical application. Mechanically scanned antennas also suffer from large size, slow scanning speed, and high cost. Therefore, researching a low-cost, simple-structured, and broadly applicable beam scanning antenna is of great significance.

[0003] A frequency scanning antenna is an antenna whose electromagnetic beam direction changes with frequency. This type of antenna can not only achieve electrically controlled beam scanning by changing the signal source frequency, but can also achieve simultaneous wide-area coverage using broadband signals. It has the advantages of low cost and the ability to perform frequency-domain beam scanning. Currently, frequency scanning antennas are mainly implemented using waveguide slot antennas, artificial electromagnetic metamaterials, gradient feed networks, and offset-feed arrays. Frequency scanning antennas based on waveguide slot antennas have a simple structure and a wide applicable frequency band, but a small scanning range and a narrow operating bandwidth. Frequency scanning antennas based on artificial electromagnetic metamaterials have a large scanning range but are only applicable to low-frequency bands and have a complex structure. Frequency scanning antennas based on gradient feed networks have a wide applicable frequency band, a large scanning range, and are easy to achieve two-dimensional scanning, but are bulky and have high processing costs. Frequency scanning antennas based on offset-feed arrays have a wide applicable frequency band and a small size, but a small scanning range and cannot perform two-dimensional scanning.

[0004] In summary, existing frequency-scanning antennas still have some issues, making them difficult to meet the current application requirements of high-frequency communications, radar, and imaging systems such as terahertz. Therefore, the development of a compact, low-cost, two-dimensionally scannable terahertz frequency-scanning antenna is of great significance. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a terahertz multi-beam frequency-scanning antenna based on a dielectric lens.

[0006] The object of the present invention is achieved through the following technical solutions:

[0007] A first aspect of the present invention provides a terahertz multi-beam frequency-sweeping antenna based on a dielectric lens, comprising:

[0008] A feed array comprises a metal substrate and a rectangular waveguide feed array provided on the metal substrate;

[0009] A right-angled trapezoidal metal cavity, comprising a right-angled waist side and an oblique waist side; the right-angled waist side of the right-angled trapezoidal metal cavity is connected to the feed side of the rectangular waveguide feeding array;

[0010] The frequency-shift dielectric lens includes a dielectric substrate and a dielectric shaping lens located above the dielectric substrate; the dielectric substrate is connected to the oblique waist side of a right-angled trapezoidal metal cavity; the dielectric shaping lens includes N*M shaping units distributed horizontally and vertically along the dielectric substrate, the length and width of each shaping unit are equal, and the height of each shaping unit is calculated as follows:

[0011] Taking the center position of the frequency-shift dielectric lens as the coordinate origin, the phase distribution φ of each shaping unit of the frequency-shift dielectric lens is ij Satisfies the formula:

[0012]

[0013] According to the phase distribution φ ij , calculate the height distribution of each shaping unit:

[0014] Where λ0 is the vacuum wavelength corresponding to the central operating frequency, F is the focal length of the frequency-shifting dielectric lens, (Fcosα,0,Fsinα) is the coordinate of the center position of the feed array, α is the bottom angle of the right-angled trapezoidal metal cavity, (x ij ,y i ) is the center coordinate of the corresponding shaping unit located on the plane of the dielectric substrate, is the beam pointing direction of the antenna center operating frequency, ε r is the dielectric constant of the dielectric material used in the frequency-shifting dielectric lens.

[0015] Furthermore, each rectangular waveguide in the rectangular waveguide feed array is arranged laterally and is identical, and the size of the rectangular waveguide is an international standard waveguide size, and the corresponding rectangular waveguide size is selected according to the center operating frequency of the antenna;

[0016] The arrangement period of the rectangular waveguide feeding array must be greater than the width of the rectangular waveguide.

[0017] Furthermore, the median line of the right-angled trapezoidal metal cavity is equal to the focal length of the frequency-shifting dielectric lens, the height of the right-angled trapezoidal metal cavity is equal to the height of the metal substrate, and the width of the right-angled trapezoidal metal cavity is equal to the width of the metal substrate.

[0018] Furthermore, the metal substrate and the outer shell of the right-angled trapezoidal metal cavity are made of one of aluminum, copper, silver, nickel and gold;

[0019] The dielectric substrate and dielectric shaping lens are made of one of photosensitive resin, high molecular polymer, silicon and quartz materials.

[0020] Furthermore, the length and width of the shaping unit need to be less than or equal to 1 / 2 of the working wavelength.

[0021] Furthermore, the bottom angle α of the right-angled trapezoidal metal cavity is less than 90°.

[0022] The beneficial effects of the present invention are:

[0023] In an exemplary embodiment of the present invention, the fusion of time domain beam scanning and frequency domain beam scanning is achieved by integrating a feeding array and a frequency-shifting dielectric lens, which has the advantages of time-frequency fusion two-dimensional scanning and high beam resolution; and by adopting a frequency-shifting dielectric lens to realize the offset and radiation end, it has the advantages of arbitrary gain expansion, no grating lobes, and a large working bandwidth; by adopting a multi-port feeding array, it has the advantages of a large beam scanning range and the ability to modify and expand the scanning range. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic structural diagram of a terahertz multi-beam frequency-sweeping antenna based on a dielectric lens provided in an exemplary embodiment of the present invention;

[0025] Figure 2 A schematic structural diagram of a frequency-shifting dielectric lens provided in an exemplary embodiment of the present invention

[0026] Figure 3 This is a transverse time-domain beam scanning pattern at 150 GHz of a terahertz multi-beam frequency-sweeping antenna based on a dielectric lens provided in an exemplary embodiment of the present invention;

[0027] Figure 4 A longitudinal frequency domain beam scanning pattern of a terahertz multi-beam frequency-sweeping antenna based on a dielectric lens provided in an exemplary embodiment of the present invention at 120 to 170 GHz;

[0028] In the figure, 1-feed array, 101-metal substrate, 102-rectangular waveguide feeding array, 2-right-angle trapezoidal metal cavity, 3-frequency-shifting dielectric lens, 301-dielectric substrate, 302-dielectric shaping lens. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is described clearly and completely below with reference to the accompanying drawings. It is apparent that the embodiments described are only a portion of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0030] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as "center," "up," "down," "left," "right," "vertical," "horizontal," "inside," and "outside" are based on the directions or positional relationships described in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, terms such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention.

[0032] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0033] See also Figure 1 , Figure 1 A terahertz multi-beam frequency-sweeping antenna based on a dielectric lens provided in an exemplary embodiment of the present invention is shown, comprising:

[0034] The feed array 1 includes a metal substrate 101 and a rectangular waveguide feed array 102 provided on the metal substrate 101;

[0035] The right-angled trapezoidal metal cavity 2 includes a right-angled waist side and an oblique waist side; the right-angled waist side of the right-angled trapezoidal metal cavity 2 is connected to the feed side of the rectangular waveguide feeding array 102;

[0036] like Figure 2As shown, the frequency-shift dielectric lens 3 includes a dielectric substrate 301 and a dielectric shaping lens 302 located above the dielectric substrate 301; the dielectric substrate 301 is connected to the oblique waist side of the right-angled trapezoidal metal cavity 2; the dielectric shaping lens 302 includes N*M shaping units distributed horizontally and vertically along the dielectric substrate 301, the length and width of each shaping unit are equal, and the height of each shaping unit is calculated as follows:

[0037] Taking the center position of the frequency-shift dielectric lens 302 as the coordinate origin, the phase distribution φ of each shaping unit of the frequency-shift dielectric lens 302 is ij Satisfies the formula:

[0038]

[0039] According to the phase distribution φ ij , calculate the height distribution of each shaping unit:

[0040] Where λ0 is the vacuum wavelength corresponding to the central operating frequency, F is the focal length of the frequency-shifting dielectric lens, (Fcosα,0,Fsinα) is the coordinate of the center position of the feed array, α is the bottom angle of the right-angled trapezoidal metal cavity, (x ij ,y i ) is the center coordinate of the corresponding shaping unit located on the plane of the dielectric substrate, is the beam pointing direction of the antenna center operating frequency, ε r is the dielectric constant of the dielectric material used in the frequency-shifting dielectric lens.

[0041] Specifically, in this exemplary embodiment, the terahertz wave is fed from the feeding side of the feed array 1, passes through the right-angled trapezoidal metal cavity 2, and then enters the frequency-shifting dielectric lens 3. By precisely shaping the structure of the frequency-shifting dielectric lens 3, frequency domain scanning of terahertz waves incident at any angle can be achieved. At the same time, by switching the ports in the feed array 1, high-gain, large-angle time-frequency fusion two-dimensional beam scanning of the terahertz wave can be achieved. In addition, in this exemplary embodiment, the shaping method of the frequency-shifting dielectric lens 3 structure is disclosed. Time domain beam scanning in the X direction is achieved by switching the feed array 1; frequency domain scanning is achieved by generating a path difference through the offset feed lens.

[0042] In summary, in this exemplary embodiment, the fusion of time domain beam scanning and frequency domain beam scanning is achieved by integrating the feeding array and the frequency-shifting dielectric lens, which has the advantages of time-frequency fusion two-dimensional scanning and high beam resolution; and by adopting the frequency-shifting dielectric lens to realize the offset and radiation end, it has the advantages of arbitrary gain expansion, no grating lobes, and large working bandwidth; by adopting the multi-port feeding array, it has the advantages of a large beam scanning range and the ability to modify and expand the scanning range.

[0043] The following content will describe in detail the preferred exemplary embodiments of each structure:

[0044] More preferably, in an exemplary embodiment, each rectangular waveguide in the rectangular waveguide feed array 102 is arranged laterally and is identical, and the size of the rectangular waveguide is an international standard waveguide size, and the corresponding rectangular waveguide size is selected according to the center operating frequency of the antenna;

[0045] The arrangement period of the rectangular waveguide feeding array 102 must be greater than the width of the rectangular waveguide.

[0046] Specifically, in this exemplary embodiment, the rectangular waveguide feed array 102 is described in detail: the thickness of the metal substrate 101 is consistent with that of the rectangular waveguide array 102, and the height and width of the metal substrate 101 must be greater than those of the rectangular waveguide feed array 102. Furthermore, each rectangular waveguide in the rectangular waveguide feed array 102 is arranged horizontally and is identical. The dimensions of the rectangular waveguides conform to international standard waveguide dimensions, and the corresponding rectangular waveguide dimensions are selected based on the antenna's central operating frequency. The arrangement period of the rectangular waveguide feed array 102 must be greater than the width of the rectangular waveguides.

[0047] For example, the central operating frequency f of the terahertz multi-beam frequency-sweeping antenna is 150 GHz, the operating wavelength λ0 is 2 mm, and the focal length F of the frequency-shifting dielectric lens 3 is 6 mm. This frequency belongs to the D waveguide, and the corresponding standard rectangular waveguide has a height of 0.83 mm and a width of 1.65 mm. Therefore, in this exemplary embodiment, the thickness (Z direction), width (X direction), and height (Y direction) of the metal substrate 101 are 2 mm, 10.4 mm, and 7.47 mm, respectively. The rectangular waveguide feed array 102 has 7 feed ports, each of which has a length (Z direction), width (X direction), and height (Y direction) of 2 mm, 0.83 mm, and 1.65 mm, respectively. The lateral period (X direction) of the rectangular waveguide feed array 102 is 1.5 mm.

[0048] More preferably, in an exemplary embodiment, the midline of the right-angled trapezoidal metal cavity 2 is equal to the focal length of the frequency-shifting dielectric lens 3 , the height of the right-angled trapezoidal metal cavity 2 is equal to the height of the metal substrate 101 , and the width of the right-angled trapezoidal metal cavity 2 is equal to the width of the metal substrate 101 .

[0049] Specifically, in this exemplary embodiment, the rectangular trapezoidal metal cavity 2 is described in detail: the midline length (Z direction) of the cavity in the rectangular trapezoidal metal cavity 2 is equal to the focal length of the frequency-shifting dielectric lens 3, which is 6 mm; the width is 10 mm; and the right-angle waist height is 7.07 mm. The angle between the waist and the ZOX plane (the waist base angle) α in the rectangular trapezoidal metal cavity 2 is preferably 45°, and the waist length is 10 mm. The midline length (Z direction), width, right-angle waist height, and waist length of the metal shell in the rectangular trapezoidal metal cavity 2 are 6 mm, 10.4 mm, 7.47 mm, and 10.4 mm, respectively.

[0050] It should be additionally noted that, in a preferred exemplary embodiment, the slant waist bottom angle α of the right-angled trapezoidal metal cavity 2 needs to be less than 90° to generate a path difference, and only with a path difference can frequency scanning be achieved; the greater the path difference, the larger the scanning angle, but if the slant waist bottom angle is too small, the beam performance will deteriorate, so an angle of 45° is used.

[0051] More preferably, in an exemplary embodiment, the dielectric substrate 301 and the dielectric shaping lens 302 adopt a dielectric constant ε r =2.739 photosensitive resin material, wherein the thickness, width, and height (along the waist direction) of the dielectric substrate 301 are 0.1 mm, 10.4 mm, and 10.4 mm, respectively; the dielectric substrate 301 is parallel to the plane where the waist of the right-angled trapezoidal metal cavity 2 is located, and the angle between the dielectric substrate 301 and the ZOX plane (the waist base angle) is 45°.

[0052] The dielectric shaping lens 302 includes 100 shaping units, and the width and period of each shaping unit in the horizontal and vertical directions (parallel to the plane of the dielectric substrate 301) are equal and 0.5 mm; the 150 GHz pointing direction of the dielectric shaping lens 302 is θ0=90°. Taking the center position of the frequency shift medium lens as the coordinate origin, the center coordinates of each shaping unit (x ij ,y ij , 0), focal length of the frequency-shift dielectric lens, λ0 = 2 mm, dielectric constant ε r = 2.739, the beam pointing to the center operating frequency is (φ0, θ0), and the phase distribution φ ij formula:

[0053]

[0054] The required height of each shaping unit can be calculated

[0055] More preferably, in an exemplary embodiment, the metal substrate 101 and the outer shell of the right-angled trapezoidal metal cavity 2 are made of one of aluminum, copper, silver, nickel and gold.

[0056] Specifically, in this exemplary embodiment, a structure in which a dielectric lens is loaded in an all-metal metal cavity is adopted, which has the advantages of easy processing, small size, and integrated design of the feed array and the lens.

[0057] More preferably, in an exemplary embodiment, the length and width of the shaping unit should be less than or equal to 1 / 2 of the working wavelength. The smaller the length and width of the shaping unit, the smoother the dielectric shaping lens.

[0058] In summary, all parameters of this example can be obtained, and the feed array 1, the right-angled trapezoidal metal cavity 2 and the frequency-shifting dielectric lens 3 are connected together (perhaps by bonding) to form a complete terahertz multi-beam frequency-sweeping antenna structure.

[0059] The terahertz multi-beam frequency-sweeping antenna modeling and simulation were carried out using CST three-dimensional electromagnetic field simulation software. According to the calculation results, Figure 3 The lateral time-domain beam scanning simulation results of the terahertz multi-beam frequency-sweeping antenna when switching between ports 1 to 7 are shown. The beam pointing is in the theta = 90° plane. The beam pointing of ports 1 and 7 is phi = 56 / 124°, with a beam gain of 13.1dBi; the beam pointing of ports 2 and 6 is phi = 66 / 114°, with a beam gain of 14.3dBi; the beam pointing of ports 3 and 5 is phi = 77 / 103°, with a beam gain of 14.1dBi; the beam pointing of port 4 is phi = 90°, with a beam gain of 15.2dBi.

[0060] like Figure 4 The shown results are the gain-normalized longitudinal frequency-domain beam scanning simulation results of the terahertz multi-beam frequency-sweeping antenna in the frequency domain of 120 to 170 GHz. The beam pointing is in the phi = 90° plane. The beam pointing at 120 GHz is theta = 63°, with a beam gain of 13 dBi; the beam pointing at 130 GHz is theta = 74°, with a beam gain of 14.7 dBi; the beam pointing at 140 GHz is theta = 84°, with a beam gain of 14.2 dBi; the beam pointing at 150 GHz is theta = 90°, with a beam gain of 15.2 dBi; the beam pointing at 160 GHz is theta = 97°, with a beam gain of 17.7 dBi; and the beam pointing at 170 GHz is theta = 100°, with a beam gain of 16.3 dBi.

[0061] The above-mentioned terahertz multi-beam frequency-scanning antenna based on frequency-shifting dielectric lens realizes a two-dimensional time-frequency beam scanning range of 36°×68° by changing the feeding port. The average gain during transverse time domain beam scanning is 14.1dBi; the average gain during longitudinal frequency domain beam scanning is 15.18dBi; the overall size (length×width×height) is approximately: 10.3mm×10.4mm×7.47mm; the terahertz multi-beam frequency-scanning antenna can simultaneously realize frequency domain scanning and time domain scanning, and has the advantages of large two-dimensional beam scanning range, scalable gain, small size and low cost, and is of great value in terahertz communication, radar and imaging applications.

[0062] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications can be made based on the above descriptions. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications derived therefrom remain within the scope of protection of the present invention.

Claims

1. A terahertz multi-beam frequency-sweeping antenna based on a dielectric lens, characterized by: include: A feed array comprises a metal substrate and a rectangular waveguide feed array provided on the metal substrate; A right-angled trapezoidal metal cavity, comprising a right-angled waist side and an oblique waist side; the right-angled waist side of the right-angled trapezoidal metal cavity is connected to the feed side of the rectangular waveguide feeding array; The frequency-shift dielectric lens includes a dielectric substrate and a dielectric shaping lens located above the dielectric substrate; the dielectric substrate is connected to the oblique waist side of a right-angled trapezoidal metal cavity; the dielectric shaping lens includes N*M shaping units distributed horizontally and vertically along the dielectric substrate, the length and width of each shaping unit are equal, and the height of each shaping unit is calculated as follows: Taking the center position of the frequency-shift dielectric lens as the coordinate origin, the phase distribution of each shaping unit of the frequency-shift dielectric lens is Satisfies the formula: ； According to the phase distribution , calculate the height distribution of each shaping unit: ; Where λ0 is the vacuum wavelength corresponding to the central operating frequency, F is the focal length of the frequency-shifting dielectric lens, is the coordinate of the center position of the feed array, α is the bottom angle of the right-angle trapezoidal metal cavity, (x ij , y ij ) is the center coordinate of the corresponding shaping unit located on the plane of the dielectric substrate, is the beam pointing direction of the antenna center operating frequency, is the dielectric constant of the dielectric material used in the frequency-shifting dielectric lens.

2. The terahertz multi-beam frequency-sweeping antenna based on a dielectric lens according to claim 1, characterized in that: Each rectangular waveguide in the rectangular waveguide feed array is arranged laterally and is identical. The size of the rectangular waveguide is an international standard waveguide size, and the corresponding rectangular waveguide size is selected according to the center operating frequency of the antenna; The arrangement period of the rectangular waveguide feeding array is greater than the width of the rectangular waveguide.

3. The terahertz multi-beam frequency-sweeping antenna based on a dielectric lens according to claim 1, characterized in that: The median line of the right-angled trapezoidal metal cavity is equal to the focal length of the frequency-shifting dielectric lens, the height of the right-angled trapezoidal metal cavity is equal to the height of the metal substrate, and the width of the right-angled trapezoidal metal cavity is equal to the width of the metal substrate.

4. The terahertz multi-beam frequency-sweeping antenna based on a dielectric lens according to claim 1, characterized in that: The metal substrate and the outer shell of the right-angled trapezoidal metal cavity are made of one of aluminum, copper, silver, nickel and gold; The dielectric substrate and dielectric shaping lens are made of one of photosensitive resin, high molecular polymer, silicon and quartz materials.

5. The terahertz multi-beam frequency-sweeping antenna based on a dielectric lens according to claim 1, characterized in that: The length and width of the shaping unit must be less than or equal to 1 / 2 of the working wavelength.

6. The terahertz multi-beam frequency-sweeping antenna based on a dielectric lens according to claim 1, characterized in that: The oblique waist bottom angle α of the right-angled trapezoidal metal cavity is less than 90°.

Images