Leaky-wave antenna and manufacturing method thereof

Abstract

The invention relates to the technical field of antennas, in particular to a leaky-wave antenna and a manufacturing method thereof. The antenna comprises a parallel slab waveguide, a rectangular slot array, a paraboloid groove body and a rectangular groove body, the parallel slab waveguide comprises a first slab and a second slab located below the first slab; the rectangular seam array is arranged in the first flat plate, and the rectangular seam array is formed by periodically arranging a plurality of rectangular seam units; the paraboloid groove body is arranged in the second flat plate; the rectangular slot body is arranged in the second flat plate, and the rectangular slot body is respectively communicated with the rectangular slot array and the paraboloid slot body, and the antenna aims to improve the gain of the antenna and reduce the processing difficulty.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of antennas, in particular to a leaky-wave antenna and a manufacturing method thereof. BACKGROUND

[0002] Terahertz waves (0.1-10 THz) as a promising frequency band in the electromagnetic spectrum, with its wide bandwidth, high capacity, low latency and excellent penetration characteristics, has shown broad application prospects in medical detection, security inspection and wireless communication.

[0003] In recent years, various terahertz lens antenna schemes have been proposed by researchers, however, these lens antennas need to rely on complex optical path adjustment systems, resulting in an increase in antenna profile size; further, in order to improve the integration of communication equipment, traveling wave antennas (such as leaky-wave antennas) are concerned due to their low profile characteristics.

[0004] However, traditional traveling wave antennas are mostly one-dimensional structures with limited radiation area, and the gain performance is difficult to meet the demand. In the existing scheme, researchers have proposed a scheme using a metal hole array structure combined with a parallel plate waveguide structure, which has realized a leaky-wave antenna with high radiation efficiency (90%) and high gain (33.3 dBi) at 0.14 THz, but the antenna contains hundreds of superstructure holes, which has high manufacturing difficulty.

[0005] Therefore, how to improve the gain of the antenna and reduce the processing difficulty has become a problem to be solved. SUMMARY

[0006] The main purpose of the present application is to provide a leaky-wave antenna and a manufacturing method thereof, aiming to improve the gain of the antenna and reduce the processing difficulty.

[0007] In a first aspect, the present application provides a leaky-wave antenna, which comprises: a parallel plate waveguide, a rectangular slot array, a parabolic groove body and a rectangular groove body; The parallel plate waveguide comprises a first plate and a second plate located below the first plate; The rectangular slot array is arranged in the first plate, and the rectangular slot array is composed of a plurality of rectangular slot units arranged periodically; The parabolic groove body is arranged in the second plate; The rectangular groove body is arranged in the second plate, and the rectangular groove body is in communication with the rectangular slot array and the parabolic groove body, respectively.

[0008] In a second aspect, the present application provides a manufacturing method of a leaky-wave antenna, which comprises: providing a first plate and a second plate; opening a rectangular slot array in the first plate; Parabolic troughs and rectangular troughs are formed in the second flat plate, and the rectangular troughs are in communication with the rectangular slot array and the parabolic troughs respectively.

[0009] According to the leaky-wave antenna and the manufacturing method thereof provided in the application, the first flat plate and the second flat plate jointly constitute a parallel flat plate waveguide, the conversion from a guided wave to a free-space wave is realized by combining the parabolic troughs and the rectangular slot array, specifically, after the terahertz wave is fed into the parallel flat plate waveguide, the divergent wave beam is first converted into a parallel wave beam after being reflected by the parabolic troughs, and the reflection of the parabolic troughs on the incident wave can realize the function of polarization conversion, at this time, the phase distribution presents gradient difference with the spatial position, further, the phase compensation of the parallel wave beam is realized by the rectangular slot array in communication with the rectangular troughs, so as to ensure that the outgoing waves at different positions are emitted with the same phase, finally, the high-gain equal-phase plane wave beam is formed, and compared with the prior art, in which the metal hole array structure with hundreds of super-structure holes needs to be combined with the parallel flat plate waveguide structure to realize the high-gain leaky-wave antenna scheme, the rectangular slot array design adopted in the application can effectively reduce the processing difficulty and production cost. BRIEF DESCRIPTION OF DRAWINGS

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0011] Figure 1 A structural schematic diagram of a first flat plate in a leaky-wave antenna according to an embodiment of the application is provided. Figure 2 A structural schematic diagram of a second flat plate in a leaky-wave antenna according to an embodiment of the application is provided. Figure 3 A structural schematic diagram of a leaky-wave antenna according to an embodiment of the application is provided. Figure 4 A reflection principle diagram of a parabolic trough in a leaky-wave antenna according to an embodiment of the application is provided. Figure 5 A far-field measurement experiment schematic diagram of a leaky-wave antenna according to an embodiment of the application is provided. Figure 6 A polarization diagram of an electric field in an x-axis direction in a leaky-wave antenna according to an embodiment of the application is provided. Figure 7 A polarization diagram of an electric field in a y-axis direction in a leaky-wave antenna according to an embodiment of the application is provided. Figure 8A schematic diagram of the relationship between a rectangular slot array and an exit bit in a leaky-wave antenna is provided for an embodiment of the present application; Figure 9 A schematic diagram of the relationship between a rectangular slot side length, transmittance and phase in a leaky-wave antenna is provided for an embodiment of the present application; Figure 10 A flowchart of a manufacturing method of a leaky-wave antenna is provided for an embodiment of the present application; Figure 11 A three-dimensional radiation schematic diagram of a leaky-wave antenna is provided for an embodiment of the present application; Figure 12 An H-plane and E-plane radiation schematic diagram of a leaky-wave antenna is provided for an embodiment of the present application; Figure 13 A relationship diagram between antenna gain and S11 corresponding to different frequencies in a leaky-wave antenna is provided for an embodiment of the present application; Figure 14 H-plane radiation schematic diagrams of a leaky-wave antenna at frequencies of 0.135, 0.14 and 0.145 THz are provided for an embodiment of the present application; Figure 15 An overall physical sample diagram of a leaky-wave antenna is provided for an embodiment of the present application; Figure 16 A physical sample diagram of a first plate and a second plate in a leaky-wave antenna is provided for an embodiment of the present application; Figure 17 An H-plane experimental and simulation radiation schematic diagram in a leaky-wave antenna is provided for an embodiment of the present application; Figure 18 An E-plane experimental and simulation radiation schematic diagram in a leaky-wave antenna is provided for an embodiment of the present application. DETAILED DESCRIPTION

[0012] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0013] The flowcharts shown in the drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor do they have to be executed in the described order. For example, some operations / steps can be further decomposed, combined or partially merged, so the actual execution order can be changed according to the actual situation.

[0014] As a highly promising frequency band in the electromagnetic spectrum, terahertz waves (0.1-10 THz) have shown broad application prospects in medical testing, security inspections, wireless communications and other fields due to their wide bandwidth, high capacity, low latency and excellent penetration characteristics.

[0015] In recent years, researchers have proposed various terahertz lens antenna solutions. However, these lens antennas rely on complex optical path adjustment systems, which leads to an increase in the antenna cross-sectional size. Furthermore, to improve the integration of communication equipment, traveling wave antennas (such as leaky wave antennas) have attracted attention due to their low-profile characteristics.

[0016] However, traditional traveling-wave antennas are mostly one-dimensional structures with limited radiation area, and their gain performance cannot meet the required requirements. Among existing solutions, researchers have proposed combining a metal hole array structure with a parallel plate waveguide structure, achieving a leaky-wave antenna with high radiation efficiency (90%) and high gain (33.3 dBi) at 0.14 THz. However, this antenna contains hundreds of meta-holes, which makes it difficult to manufacture.

[0017] Based on this, an embodiment of the present application provides a leaky wave antenna and a method for manufacturing the same, aiming to improve the gain of the antenna and reduce the difficulty of processing.

[0018] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0019] Please refer to Figures 1-3 In a first aspect, an embodiment of the present application provides a leaky wave antenna, the antenna comprising: a parallel plate waveguide, a rectangular slot array 110, a parabolic trough 210, and a rectangular trough 220; The parallel plate waveguide includes a first plate 100 and a second plate 200 located below the first plate 100; The rectangular slot array 110 is provided in the first plate 100 , and the rectangular slot array 110 is composed of a plurality of rectangular slot units 111 arranged in a periodic manner; The parabolic trough 210 is disposed in the second flat plate 200; The rectangular slot body 220 is disposed in the second flat plate 200 , and the rectangular slot body 220 is communicated with the rectangular slot array 110 and the parabolic slot body 210 respectively.

[0020] like Figure 3 As shown, a three-axis rectangular coordinate system is established with three sides connected and perpendicular to each other on the rectangular cylinder, including: x-axis, y-axis and z-axis. The width of the rectangular slit unit 111 is , the depth of the rectangular slit unit 111 is .

[0021] It should be noted that, in the parallel plate waveguide, a parabolic trough 210 is cut out along a parabolic trajectory in the second plate 200. The parabolic trough 210 enables the parallel plate waveguide to have the ability to convert the propagation direction of the beam, such as Figure 4 As shown, the polarization direction is converted from the x-axis to the y-axis. In addition, the parabolic trough 210 is used to convert the incident one-dimensional traveling wave reflection into a two-dimensional beam, from linear radiation with a small radiation area to surface radiation with a large radiation area, which can provide higher gain; the rectangular trough 220 is used to provide a channel to transmit the two-dimensional beam converted by the parabolic trough 210 to the rectangular slot array 110; the rectangular slot array 110 is used to perform phase control on the two-dimensional beam.

[0022] In the prior art, to achieve a high-gain leaky-wave antenna, a scheme has been proposed that requires the use of a metal hole array structure with hundreds of meta-holes combined with a parallel plate waveguide structure to achieve a leaky-wave antenna with high radiation efficiency (90%) and high gain (33.3 dBi) at 0.14 THz. However, due to the small size and large number of meta-holes involved in this scheme, the machining process requires a special small-sized milling cutter or forming drill bit, which increases machining complexity and requires complex tool path planning, resulting in low machining efficiency. In contrast, the present application only requires the formation of a rectangular slot array 110 composed of a plurality of periodically arranged rectangular slot units 111 in the first plate 100, and the formation of a parabolic trough 210 and a rectangular trough 220 in the second plate 200 to obtain a high-gain leaky-wave antenna. The rectangular slot units 111, which are relatively complex to machine, can be machined using milling cutters, laser cutting, or wire cutting. The tool diameter or cutting width can be flexibly selected according to the slot width, eliminating the need for complex tool replacement, simplifying tool path planning, and significantly reducing machining complexity.

[0023] According to a leaky wave antenna provided in an embodiment of the present application, an incident port 230 is provided in the second plate 200, and the incident port 230 is provided at the focal position of the parabolic trough 210, such as Figure 2 As shown, the incident port 230 cooperates with the output port of the feed source 300, as shown Figure 5 shown.

[0024] Preferably, the frequency of the feed source 300 is 0.14 THz. The frequency of the feed source 300 can be appropriately adjusted within the range of 0.135-0.146. In this application, no excessive restrictions are imposed on the frequency of the feed source 300.

[0025] Preferably, the outlet of the feed source 300 is a rectangular structure, and the incident port 230 in the second plate 200 is also a rectangular structure. In this application, no excessive restrictions are imposed on the structure of the outlet of the feed source 300 and the structure of the incident port 230 in the second plate 200.

[0026] It can be understood that the incident port 230 is arranged at the focal point position of the parabolic trough 210, and the terahertz wave output by the feed source 300 is incident from the focal point position and can be reflected by the parabolic trough 210 to be parallelly emitted to the rectangular slot array 110 at the rear, so that the rectangular slot array 110 can be used to regulate only one direction.

[0027] The designed leaky-wave antenna is simulated by using a commercial simulation software comsol multiphysics, Figure 6 and Figure 7 The x-polarization and y-polarization diagrams of the electric field are shown in FIGS. 7 and 8, respectively. It can be seen that the TE10 mode is incident from the incident port 230, and the polarization direction is changed after being reflected by the parabolic trough 210.

[0028] It can be understood that, since the incident port 230 cooperates with the exit port of the feed source 300, the incident port 230 and the exit port of the feed source 300 can be directly connected without the need to add additional collimating optical path devices and complex processes, and have a low profile feature, which is convenient for communication system integration.

[0029] In some embodiments, the width of each rectangular slot unit 111 in the rectangular slot array 110 is less than wherein λ represents the wavelength of the incident wave.

[0030] Preferably, the width of the rectangular slot unit 111 is 2 mm, the rectangular slot array 110 is composed of 20 rectangular slot units 111 arranged periodically, and the width of the rectangular slot array 110 is 40 mm. In the present application, the width of the rectangular slot unit 111 and the number of the rectangular slot units 111 are not limited.

[0031] According to the leaky-wave antenna provided in the embodiments of the present application, the length of the rectangular slot array 110 is 19λ, the width of the rectangular slot array 110 is 19λ, the maximum width of the parabolic trough 210 is the same as the length of the rectangular slot array 110, and the length of the parabolic trough 210 is determined by a preset parabolic equation, wherein λ represents the wavelength of the incident wave.

[0032] It should be noted that the preset parabolic equation formula for determining the length of the parabolic trough 210 is:

[0033] wherein, W is the width of the parabolic trough 210, L is the length of the parabolic trough, F is the distance from the focal point to the directrix.

[0034] It should be noted that when the parameter If the length of the parabolic trough 210 is too large or too small, the performance of the antenna will be affected.

[0035] Preferably, The distance from the focal point to the directrix is 16mm, and the distance from the focal point to the directrix is not limited in the present application.

[0036] Preferably, if the length of the rectangular slot array 110 is 40mm, the width of the rectangular slot array 110 is 40mm, and the maximum width of the parabolic trough 210 is 40mm, The length of the parabolic trough 210 is 50mm.

[0037] It should be noted that the length of the rectangular slot array 110 is 19λ, the width of the rectangular slot array 110 is 19λ, and the length of the rectangular slot array 110 is comparable to the width of the rectangular slot array 110, which can make the radiation energy more uniform.

[0038] It should be noted that the width of the parallel plate waveguide is slightly larger than the maximum width of the parabolic trough 210, and the width of the parallel plate waveguide can be adaptively adjusted within the range of 40.5-12mm.

[0039] According to the leaky-wave antenna provided in the embodiments of the present application, the width of the rectangular slot 10 in different rectangular slot units 111 is determined according to the first target delay phase and the second target delay phase; the first target delay phase is determined according to the first propagation constant and the horizontal distance from the end of the parabolic trough 210 to the target rectangular slot; and the second target delay phase is determined according to the second propagation constant and the depth of the target rectangular slot.

[0040] It should be noted that the sum of the first target delay phase and the second target delay phase is a first preset value.

[0041] Preferably, the sum of the first target delay phase and the second target delay phase can be 350° or 360°, and the sum of the first target delay phase and the second target delay phase is not limited in the present application.

[0042] It should be noted that the two-dimensional beam transmission to different positions of the rectangular slot array 110 corresponds to different phases, in order to improve the gain of the antenna, the radiated wave needs to be out of phase on the rectangular slot array 110, by designing the rectangular slot 10 in the rectangular slot unit 111 as different sizes, the rectangular slot 10 of different width sizes can provide different phase delays when the radiated wave is coupled out of the rectangular slot 10, so as to realize equal phase out; further, first, the first target delay phase is calculated, second, the second target delay phase is determined according to the relationship that the sum of the first target delay phase and the second target delay phase is a first preset value, and finally, the width of the target rectangular slot is obtained by calculating the second target delay phase formula.

[0043] When the two-dimensional TE guided mode propagates to the rectangular slot array 110, the phase compensation required by each rectangular slot 10 at different positions in the array can be calculated based on the formula for calculating the first target delay phase. Since the parabolic trough body 210 has converted the incident wave into a parallel out-of-beam, the phase gradient is only distributed along the x direction, significantly simplifying the complexity of multi-dimensional phase control. By arranging the rectangular slot units 111 with rectangular slots 10 of different widths, the phase difference of the two-dimensional guided mode in different spaces can be compensated, and the equal phase plane output of the free space radiation field can be realized, as shown in Figure 8 Compared with traditional one-dimensional phase control devices, using the rectangular slot array 110 can realize the control of any phase, not only enhancing the control ability of the beam pointing and shape, but also significantly improving the antenna gain by expanding the effective radiation area.

[0044] It should be noted that when the width of the parallel plate waveguide is large enough and much larger than the working wavelength, the reflection on the boundary perpendicular to the y axis can be ignored, so the first propagation constant of the m-order transverse electric (TE) mode transmitted in the waveguide can be calculated by the following formula:

[0045] wherein, is the wave number, is 1, refers to the refractive index of air, is the plate spacing.

[0046] It should be noted that the wave number can be calculated by the following formula:

[0047] According to the leaky wave antenna provided in the embodiments of the present application, a first preset formula for determining the first target delay phase is: ; wherein, is the first target delay phase, is an initial phase, is a first propagation constant corresponding to the parallel-plate waveguide, is a horizontal distance from the end of the parabolic trough 210 to the target rectangular slot unit, because the terahertz wave is parallel after being reflected by the parabolic trough 210, only one-dimensional phase change along the x direction needs to be considered. The first propagation constant is determined by the plate spacing, which is the distance between the parabolic trough 210 and the inner surface of the first plate 100, and the plate spacing is in the range of 0.5λ to λ, where λ represents the wavelength of the incident wave.

[0048] It should be noted that when the plate spacing is in the range of 0.5λ to λ, only the TE1 mode can be transmitted in the waveguide, the mode propagates along the straight line direction perpendicular to the cross section of the waveguide, and the phase is uniformly distributed on the cross section of the waveguide, at this time the first propagation constant can be obtained by the following formula:

[0049] Preferably, the frequency of the feed source 300 is 0.14 THz, and the plate spacing is 2 mm, and the value of the first propagation constant can be determined according to the frequency of the feed source 300 and the plate spacing.

[0050] It should be noted that the distance between the rectangular trough 220 and the inner surface of the first plate 100 is the same as the distance between the parabolic trough 210 and the inner surface of the first plate 100, so that the mode propagates along the x axis direction and the first propagation constant remains unchanged within the range of the parallel-plate waveguide under the premise that the plate spacing remains unchanged.

[0051] When the incident port 230 with a sub-wavelength (greater than half a wavelength and less than a wavelength) thickness is used, the TE propagation mode limited in the z-axis direction can be freely propagated in the x-y plane and diverged in the form of a columnar wave with a limited height, which is different from the one-dimensional TE mode and can be called a two-dimensional TE mode. And the slight distortion of the wavefront near the boundary perpendicular to the y-axis is caused by the boundary reflection, which has minimal impact on the propagation characteristics.

[0052] In different propagation directions, the propagation constant is the same, and the first preset formula for determining the first target delay phase can be further converted as follows: ; Where N is the number of rectangular slots 10, and T is the period of each rectangular slot unit 111, that is, the width of each rectangular slot unit 111, and the phase required by the rectangular slot 10 at different positions can be obtained according to the above formula for determining the first target delay phase.

[0053] For example, the rectangular slot units 111 in the rectangular slot array 110 are sorted from near to far according to the distance from the end of the parabolic trough 210, and the first rectangular slot center position is taken as the phase reference. When the target rectangular slot is a rectangular slot inside the second rectangular slot unit, the horizontal distance of the target rectangular slot from the end of the parabolic trough 210 is 2 mm, and the phase delay is calculated to be 283.71° by the first preset formula for determining the first target delay phase. The value of the second target delay phase can be calculated according to the relationship that the sum of the first target delay phase and the second target delay phase is 360°.

[0054] The second preset formula for determining the second target delay phase of the leaky-wave antenna provided in the embodiment of the present application is:

[0055] wherein, is the second target delay phase, is the second propagation constant corresponding to the target rectangular slot, the depth of each rectangular slot unit 111 is the same as the depth of the rectangular slot 10, and the depth of each rectangular slot unit 111 is the same, h is the depth corresponding to the target rectangular slot, and the second propagation constant is determined by the width of the target rectangular slot.

[0056] It should be noted that the formula for determining the second propagation constant is:

[0057] wherein, is the width of the target rectangular slot, and the wave number , the depth corresponding to the target rectangular slot, and the value of the second target delay phase can be used to calculate the width value of the target rectangular slot.

[0058] According to the leaky-wave antenna provided in the embodiment of the present application, the width of the rectangular slot 10 is 1.1-1.78 mm.

[0059] It should be noted that when the width of the target rectangular slot is in the subwavelength scale, only the TE10 mode can be excited, and the polarization direction is parallel to the direction in which the width of the target rectangular slot is located. Therefore, when the frequency of the feed source 300 is 0.14 THz, the width of the rectangular slot 10 at different positions in the rectangular slot array 110 is adjusted in the range of 1.1-1.78 mm, which exactly meets the requirement that the width of the target rectangular slot is in the subwavelength scale.

[0060] Further, the width of the rectangular slot unit 111 is set to 2 mm, the depth of the rectangular slot 10 is set to 4 mm, the antenna profile is 6 mm, the width of the rectangular slot array 110 is 40 mm, and the phase control characteristics are simulated and analyzed based on comsol multiphysics, and the relationship between the side length of the rectangular slot 10 and the phase delay and the transmittance is shown in FIG. 8. When the length of the rectangular slot 10 is fixed, only the width of the rectangular slot 10 is changed, and the phase delay caused by the rectangular slot 10 also changes. In the figure, the width of the rectangular slot 10 changes in the range of 1.1-1.78 mm, and the phase control range of the rectangular slot 10 can cover the complete 360°. In addition, the selected 0.14 THz terahertz wave has a higher transmittance in this range. Figure 9

[0061] It should be noted that if the width of the rectangular slot array 110 is 40 mm, the rectangular slot array 110 is composed of 20 periodically arranged rectangular slot units 111, the frequency of the feed source 300 is 0.14 THz, the plate spacing is 2 mm, the depth corresponding to each target rectangular slot is 4 mm, and the width of the rectangular slot unit 111 is 2 mm, the above data and the horizontal distance from the end of the parabolic groove 210 to the target rectangular slot are substituted into the above formula, and the width of the rectangular slot 10 at different positions can be obtained. According to the calculation, the rectangular slot units 111 in the rectangular slot array 110 are sorted from near to far according to the distance from the end of the parabolic groove 210, and the widths of the rectangular slots 10 in the 20 rectangular slot units 111 are 1.270 mm, 1.390 mm, 1.575 mm, 1.146 mm, 1.204 mm, 1.295 mm, 1.434 mm, 1.650 mm, 1.166 mm, 1.228 mm, 1.325 mm, 1.470 mm, 1.742 mm, 1.180 mm, 1.247 mm, 1.369 mm, 1.545 mm, 1.140 mm, 1.195 mm, and 1.282 mm, respectively.

[0062] In a second aspect, referring to Figure 10 The application provides a manufacturing method of a leaky-wave antenna, which comprises the following steps S101-S103: Step S101: providing a first plate 100 and a second plate 200; Step S102: opening a rectangular slot array 110 in the first plate 100; Step S103: opening a parabolic groove 210 and a rectangular groove 220 in the second plate 200, and the rectangular groove 220 is in communication with the rectangular slot array 110 and the parabolic groove 210, respectively.

[0063] ​It should be noted that the rectangular slot array 110 is composed of 20 rectangular slot units 111 arranged periodically, and a rectangular slot 10 is arranged in each rectangular slot unit 111. The length and depth of the rectangular slot 10 in each rectangular slot unit 111 are the same, and the width of each rectangular slot 10 is determined according to the first target delay phase and the second target delay phase.

[0064] The leaky-wave antenna obtained by the above manufacturing method can convert the TE1 mode of the parallel plate waveguide into the TE1 mode of the rectangular slot unit 111 in the rectangular slot array 110 after reflection by the parabolic groove body 210, expand the beam range, and change into a linear radiation source. The parabolic groove body 210 is used to phase control the guided wave, and the guided wave at different positions is ensured to be emitted at the same phase. The antenna realizes efficient conversion from guided wave to free space wave. In addition, only 20 rectangular slots 10 are needed to achieve a high gain of 33.4 dBi and a radiation efficiency of 90.1%, and the processing complexity is significantly reduced.

[0065] According to the manufacturing method of the leaky-wave antenna provided in the embodiments of the present application, when the parabolic groove body 210 and the rectangular groove body 220 are arranged in the second plate 200, the length of the rectangular slot array 110 is controlled to be 19λ, and the width of the rectangular slot array 110 is controlled to be 19λ. The width of the parabolic groove body 210 is the same as the length of the rectangular slot array 110, wherein λ represents the wavelength of the incident wave.

[0066] It should be noted that the length of the rectangular slot array 110 is set to 19λ, and the width of the rectangular slot array 110 is set to 19λ. The length of the rectangular slot array 110 is comparable to the width of the rectangular slot array 110, which can make the radiation energy more uniform.

[0067] According to the manufacturing method of the leaky-wave antenna provided in the embodiments of the present application, the incident port 230 is arranged at the focal point position of the parabolic groove body 210 in the second plate 200.

[0068] It can be understood that the incident port 230 is arranged at the focal point position of the parabolic groove body 210, and the terahertz wave output by the feed source 300 is incident from the focal point position. After reflection by the parabolic groove body 210, it can be emitted in parallel to the rear rectangular slot array 110, so that the rectangular slot array 110 can be used to control only one direction.

[0069] It can be understood that since the incident port 230 cooperates with the exit port of the feed source 300, the incident port 230 and the exit port of the feed source 300 can be directly connected without the need to increase additional collimating optical device and complex process, and have a low profile feature, which is convenient for communication system integration.

[0070] According to a leaky-wave antenna and its manufacturing method provided in the present application, a first plate 100 and a second plate 200 together form a parallel plate waveguide. The conversion from guided wave to free-space wave is achieved by combining a parabolic trough 210 with a rectangular slot array 110. Specifically, after a terahertz wave is fed into the parallel plate waveguide, it is first reflected by the parabolic trough 210, converting the divergent beam into a parallel beam. At the same time, the reflection of the incident wave by the parabolic trough 210 can achieve polarization conversion. At this time, its phase distribution exhibits gradient differences with spatial position. Furthermore, the parallel beam is phase-compensated by the rectangular slot array 110 connected to the rectangular slot 220, ensuring that the outgoing waves at different positions are emitted with the same phase, ultimately forming a high-gain equal-phase plane beam. Moreover, compared with the prior art leaky-wave antenna solution that requires the use of a metal hole array structure with hundreds of meta-holes combined with a parallel plate waveguide structure to achieve high gain, the rectangular slot array 110 design adopted in the present application can effectively reduce the difficulty of processing and production costs.

[0071] In order to verify the effectiveness of the designed leaky wave antenna, the leaky wave antenna will also be verified through the following simulation experiment examples. The following examples are only used to elaborate on the leaky wave antenna and are not intended to limit the present application.

[0072] The cross section is 2.1×2.1 The incident port 230, the far-field simulated radiation pattern of the designed leaky wave antenna is as follows Figure 11 As shown in Figure 1, where θ is the elevation angle and φ is the azimuth angle. Simulation results show that the antenna gain peak is 33.4 dBi, significantly better than traditional traveling wave antennas. Figure 12 The radiation patterns of the E-plane (including the electric field vector and the maximum radiation direction) and the H-plane (including the magnetic field vector and the maximum radiation direction) are further shown. The main lobe 3dB widths are 3.2° and 3° respectively, showing excellent beam focusing characteristics. In addition, Figure 13 The antenna's 3 dB bandwidth is shown to be in the range of 0.135-0.146 THz, with a relative bandwidth of 7.86%, and the return loss is less than -10 dB in the 0.133-0.153 THz frequency band. The above results verify that the proposed terahertz metasurface leaky-wave antenna can achieve the performance advantages of high gain, high radiation efficiency, and low return loss without a complex feeding network. In addition, the control characteristics of the phase of the rectangular slot 10 change with frequency. When the frequency changes, the antenna gain will also decrease, such as Figure 14 As shown in Figure 2, when the center frequency is offset by 0.135 THz and 0.145 THz, the center position of the main lobe deflects by 2.7° and -2.3°, respectively. This frequency-beam pointing relationship provides potential application scenarios for frequency division multiplexing technology, such as parallel data transmission through spatial separation of multi-band signals.

[0073] Based on the various dimensional data related to the parallel plate waveguide mentioned above, the test sample of the leaky wave antenna was manufactured using the electric spark cutting technology. The complete physical object is shown in Figure 15 、 Figure 16 As shown, the first plate 100 covers the second plate 200, and the first plate 100 and the second plate 200 are fixedly connected by a plurality of connecting members.

[0074] An impact ionization avalanche transit time diode is used as the feed source 300 to emit linearly polarized terahertz waves. The output port of the feed source 300 is coupled to the input port 230 of the leaky wave antenna. A terahertz power meter is used to measure the far-field radiation intensity point by point at a sufficiently far position. During the measurement, the measurement is moved along the arc at intervals of 1°. Finally, the measured results are compared with the simulation results to obtain the normalized radiation patterns of the H-plane and E-plane, respectively. Figure 17 and Figure 18 As shown in the figure, the simulation and measured results are in good agreement. When the pitch angle offset is small, the simulation and measured results are in good agreement. However, when the angle increases, the two deviate, which is mainly due to machining errors and insufficient power meter measurement accuracy.

[0075] In addition, compared with the one-dimensional terahertz leaky-wave antenna in the traditional scheme, the leaky-wave antenna proposed in this application achieves better peak gain; the two-dimensional terahertz leaky-wave antenna in the traditional scheme requires 625 meta-apertures to achieve phase control. Compared with the two-dimensional terahertz leaky-wave antenna in the traditional scheme, the leaky-wave antenna proposed in this application uses only 20 rectangular slot units 111 to achieve a gain of 33.4 dBi and a radiation efficiency of 90.1%. The number of rectangular slot units 111 is one to two orders of magnitude less than the number of meta-apertures in the two-dimensional terahertz leaky-wave antenna; overall, the leaky-wave antenna structure proposed in this application achieves a better balance between gain, efficiency, bandwidth and ease of processing, ensuring the high performance of the terahertz antenna while reducing manufacturing costs.

[0076] It should be understood that the terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in this specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0077] It should also be understood that, in the specification and the appended claims herein, the terms "comprises", "comprising", "comprised", "comprising" or other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without limitation, an element preceded by "comprises a" does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0078] The above-mentioned embodiment serial numbers of the present application are only for description, and do not represent the advantages and disadvantages of the embodiments. The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present application, and these modifications or replacements should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A leaky wave antenna, characterized in that The antenna comprises: A parallel slab waveguide, comprising a first slab and a second slab located below the first slab; A rectangular slot array is provided in the first flat plate, and is composed of a plurality of rectangular slot units arranged in a periodic manner; a parabolic trough body, wherein the parabolic trough body is arranged in the second flat plate; A rectangular trough body is provided in the second flat plate and is connected to the rectangular slot array and the parabolic trough body respectively.

2. The antenna according to claim 1, wherein An incident port is provided in the second flat plate, and the incident port is provided at a focal position of the parabolic trough.

3. The antenna according to claim 1, wherein The length of the rectangular slot array is 19λ, the width of the rectangular slot array is 19λ, the maximum width of the parabolic trough is the same as the length of the rectangular slot array, and the length of the parabolic trough is determined by a preset parabola equation, where λ represents the wavelength of the incident wave.

4. The antenna according to claim 1, wherein The width of the rectangular slits in different rectangular slit units is determined according to a first target delay phase and a second target delay phase; the first target delay phase is determined according to a first propagation constant and a horizontal distance from the end of the parabolic trough to the target rectangular slit; the second target delay phase is determined according to a second propagation constant and the depth of the target rectangular slit.

5. The antenna according to claim 4, characterized in that The first preset formula for determining the first target delay phase is: ； in, is the initial phase, is the first propagation constant corresponding to the parallel plate waveguide, is the horizontal distance from the end of the parabolic trough to the target rectangular slot unit, the first propagation constant is determined by the plate spacing, the plate spacing is the distance between the parabolic trough and the inner surface of the first plate, and the size of the plate spacing is in the range of 0.5λ to λ, where λ represents the wavelength of the incident wave.

6. The antenna according to claim 4, characterized in that The second preset formula for determining the second target delay phase is: in, The second propagation constant corresponding to the target rectangular seam, h is the depth corresponding to the target rectangular slit, and the second propagation constant is determined by the width of the target rectangular slit.

7. The antenna according to claim 4, wherein: The width of the rectangular slit is 1.1-1.78 mm.

8. A method for manufacturing a leaky wave antenna, characterized in that: The method comprises: providing a first plate and a second plate; An array of rectangular slots is provided in the first flat plate; A parabolic trough body and a rectangular trough body are provided in the second flat plate, and the rectangular trough body is communicated with the rectangular slot array and the parabolic trough body respectively.

9. The method according to claim 8, characterized in that When a parabolic trough and a rectangular trough are provided in the second flat plate, the length and width of the rectangular slit array are controlled to be 19λ and 19λ, respectively. The width of the parabolic trough is the same as the length of the rectangular slit array, where λ represents the wavelength of the incident wave.

10. The method according to claim 8, characterized in that An incident port is provided in the second flat plate at a focal position of the parabolic trough.

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