OAM silicon-based metasurface antenna
Through the design of OAM silicon-based metasurface antenna, a diffraction-free OAM beam is constructed using holographic metasurface and fisheye lenses, which solves the problem of poor signal swaying capability in the terahertz band, and achieves the improvement of data rate and channel capacity. The integrated communication system provides key support.
Patent Information
- Application Number
- CN202411526632.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-01-17
AI Technical Summary
In the process of increasing the carrier frequency to meet the demand for high data rate, the poor signal swaying capability is problematic, especially in communication technology in the terahertz band, the divergence characteristics of the OAM beam lead to limited improvement in channel capacity and data rate.
Design an OAM silicon-based metasurface antenna to build a diffraction-free OAM beam through a combination of holographic metasurface design and fisheye lens, and achieve uniform feeding and energy conversion of the OAM beam using on-chip integration of waveguides and fisheye lenses. , weakens the divergence characteristics of OAM beams and provides hardware-based mode-division multiplexing technology.
The construction of diffraction-free OAM beam has been realized, the data rate and channel capacity have been improved, and the data rate and channel capacity have been provided as an important component for the future highly integrated terahertz communication system, which has enhanced the directionality and efficiency of signal transmission.
Smart Images
Figure CN119324318A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of antenna technology, in particular to an OAM silicon-based metasurface antenna. Background Art
[0002] To meet the growing demand for higher data rates, current communication technologies choose to continue to increase the carrier frequency to the terahertz (THz) band to provide more channel capacity. For example, at the 2019 World Radiocommunication Conference (WRC-19), the International Telecommunication Union (ITU) identified a frequency range of 275–450 GHz for land mobile and fixed service applications, opening up a total of 137 GHz of spectrum for the next generation of ultra-high-speed wireless communications. However, simply increasing the frequency will lead to new problems such as poor signal obstacle avoidance. Summary of the invention
[0003] In view of the high demands of current communication technology on data rate and channel capacity, the object of the present invention is to provide an OAM silicon-based metasurface antenna.
[0004] An embodiment of the present invention includes an OAM silicon-based metasurface antenna, and the OAM silicon-based metasurface antenna includes:
[0005] Supersurface;
[0006] A wave conductor; the wave conductor is used to receive input energy;
[0007] Fisheye lens; the fisheye lens is used to convert the input energy into plane wave energy and uniformly feed the metasurface.
[0008] Furthermore, the metasurface, the fisheye lens and the waveguide body are located on the same plane.
[0009] Furthermore, the metasurface includes a plurality of unit structures, each of the unit structures is periodically arranged in a first direction and a second direction, and the first direction and the second direction are perpendicular to each other.
[0010] Furthermore, the unit structure includes a square column part, a base part and a reflecting surface, a cylindrical hollow part is provided inside the square column part, and the square column part, the base part and the reflecting surface are arranged in sequence along a third direction, and the third direction is perpendicular to the first direction and the second direction.
[0011] Furthermore, the square column part and the base part are made of high-resistance silicon material, and the reflective surface is made of copper material.
[0012] Furthermore, the equivalent surface impedance of the metasurface is:
[0013]
[0014] Among them, Z s is the equivalent surface impedance provided by the unit structure at position (x, y), x is the position of the unit structure in the first direction, y is the position of the unit structure in the second direction, j is an imaginary unit, M is a modulation parameter, r is the distance between the unit structure at position (x, y) and the center of the metasurface, r0 is the farthest distance between all the unit structures of the metasurface and the center of the metasurface, n is the effective refractive index of an electromagnetic wave with a frequency of 306 GHz on the entire metasurface, k0 is the wave number of an electromagnetic wave with a frequency of 306 GHz propagating in a vacuum, l is 1 or -1, is the spiral phase, and X is the average surface impedance of the entire metasurface.
[0015] Further, the fisheye lens comprises a first plane Maxwell half fisheye lens and a second plane Maxwell half fisheye lens;
[0016] The side where the diameter edge of the first plane Maxwell half fisheye lens is located is parallel to the first direction, and the side where the diameter edge of the first plane Maxwell half fisheye lens is located is connected to the first edge of the metasurface;
[0017] The side where the diameter edge of the second plane Maxwell half fisheye lens is located is parallel to the second direction, and the side where the diameter edge of the second plane Maxwell half fisheye lens is located is connected to the second edge of the metasurface.
[0018] Further, the waveguide body includes a first silicon waveguide and a second silicon waveguide;
[0019] The first silicon waveguide is connected to the side where the arc edge of the first planar Maxwell semi-fisheye lens is located;
[0020] The second silicon waveguide is connected to the side where the arc edge of the second planar Maxwell semi-fisheye lens is located.
[0021] Furthermore, the OAM silicon-based metasurface antenna also includes:
[0022] Substrate; the metasurface, the fisheye lens and the waveguide are integrated on the substrate.
[0023] Furthermore, the OAM silicon-based metasurface antenna is manufactured by the following steps:
[0024] Obtain a double-polished intrinsic high-resistance silicon wafer as a substrate;
[0025] Ultrasonic cleaning of silicon wafers using a cleaning agent;
[0026] Changing the surface of the silicon wafer to a hydrophilic state;
[0027] Apply photoresist on the front side of the silicon wafer and pre-bake the photoresist;
[0028] Exposing and developing the photoresist to transfer the pattern on the mask to the photoresist; the pattern on the mask corresponds to the metasurface and the fisheye lens;
[0029] Heating and hardening the developed photoresist;
[0030] Etching the silicon wafer to produce the waveguide body;
[0031] The back side of the silicon wafer is plated with chrome, copper, and gold;
[0032] Ultrasonic cleaning of silicon wafers using a cleaning agent;
[0033] Use plasma to remove photoresist from silicon wafers.
[0034] The beneficial effects of the present invention are as follows: the OAM silicon-based metasurface antenna in the embodiment can construct a diffraction-free OAM beam, thereby providing a hardware basis for realizing the mode division multiplexing technology utilizing the OAM beam, and further achieving the effect of improving the data rate and channel capacity; in addition, the antenna and the feed port in the OAM silicon-based metasurface antenna are on the same plane, which can realize on-chip integration and can become an important component of future highly integrated terahertz communication systems. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Figure 1 Schematic diagram of the overall structure of the OAM silicon-based metasurface antenna in the embodiment;
[0036] Figure 2 is a schematic diagram of a unit structure in a metasurface in an embodiment;
[0037] FIG3( a ) is a phase distribution diagram of the +1 non-diffraction OAM mode in the metasurface in the embodiment;
[0038] FIG3( b ) is a phase distribution diagram of the -1 non-diffraction OAM mode in the metasurface in the embodiment;
[0039] FIG4( a ) is a diagram showing an ideal surface impedance distribution of the metasurface in the embodiment along the X-axis (first direction);
[0040] FIG4( b ) is a diagram showing an ideal surface impedance distribution of the metasurface in the Y-axis (second direction) in the embodiment;
[0041] FIG4( c ) is an ideal surface impedance distribution diagram of the super-surface after superposition in the embodiment;
[0042] FIG5( a ) is a diagram showing the electric field intensity distribution of the +1 mode non-diffraction OAM beam obtained by simulation in the embodiment;
[0043] FIG5( b ) is a phase distribution diagram of the +1 mode undiffraction-free OAM beam obtained by simulation in the embodiment;
[0044] FIG5( c ) is a diagram showing the electric field intensity distribution of the -1 mode non-diffraction OAM beam obtained by simulation in the embodiment;
[0045] FIG5( d ) is a phase distribution diagram of the -1 mode non-diffraction OAM beam obtained by simulation in the embodiment;
[0046] Figure 6 Schematic diagram of the manufacturing steps of the OAM silicon-based metasurface antenna in the embodiment;
[0047] FIG. 7( a ) is a schematic diagram of a finished product of an OAM silicon-based metasurface antenna in an embodiment;
[0048] FIG7( b ) is a schematic diagram of the structure annotation of the finished product of the OAM silicon-based metasurface antenna in the embodiment. DETAILED DESCRIPTION
[0049] In addition to increasing the carrier frequency, developing advanced modulation technology is another way to avoid the Shannon limit. Mode division multiplexing technology using orbital angular momentum (OAM) beams can also achieve the effect of increasing data rates and channel capacity. Since the OAM states in vortex beams have infinite value possibilities and their orthogonality, they can provide a new type of physical degree of freedom for optical communication systems, and are considered to be a very important research direction for the next generation of optical communication networks.
[0050] The main challenge of using OAM beams in RF wireless communications is their inherent divergence, which means that the waves spread out as they propagate. Therefore, a large receiving antenna is required to capture most of the radiated energy and detect the azimuthal phase change (OAM information) of the received field at the receiving end. In the present invention, a vortex beam carrying +1 and -1 modes is combined with a Bessel beam, and the divergence of OAM is weakened by the non-diffraction property of Bessel, so that its energy can be transmitted in a specified direction.
[0051] In order to use OAM beams in radio frequency wireless communications, this embodiment proposes an OAM silicon-based metasurface antenna, whose overall structure is as follows: Figure 1 See Figure 1 The OAM silicon-based metasurface antenna includes a metasurface, a waveguide and a fisheye lens. The metasurface, the waveguide and the fisheye lens can be made on the same substrate, so that the metasurface, the fisheye lens and the waveguide are located on the same plane, realizing on-chip integration of the metasurface, the fisheye lens and the waveguide.
[0052] The working principle of the OAM silicon-based metasurface antenna in this embodiment is to use the holographic metasurface design principle to form a holographic wave generated by the interaction between the excitation reference wave and the target wave to achieve the construction of a diffraction-free OAM beam. Specifically, first, the frequency band of the metasurface is 300GHz-310GHz. The waveguide can be connected to the WR3 waveguide (metal waveguide) and fed through the WR3 waveguide to achieve good impedance matching; the waveguide couples the energy in the metal waveguide to the fisheye lens. The waveguide is equivalent to an energy point source. The fisheye lens can convert the point source energy input by the waveguide into plane wave energy to uniformly feed the metasurface. The OAM silicon-based metasurface antenna in this embodiment can construct a diffraction-free OAM beam, thereby providing a hardware foundation for realizing the mode division multiplexing technology using the OAM beam, thereby achieving the effect of increasing the data rate and channel capacity.
[0053] In this embodiment, refer to Figure 1 , the width and length of the substrate in the OAM silicon-based metasurface antenna are both L = 15.3 mm. A rectangular coordinate system can be established on the OAM silicon-based metasurface antenna, where the X-axis is the first direction, the Y-axis is the second direction, and the origin can be set at the center point of the metasurface. The metasurface includes a plurality of unit structures, each of which is periodically arranged in the first direction and the second direction. For example, viewed from the first direction, the plurality of unit structures are arranged in rows along the X-axis or in a direction parallel to the X-axis; viewed from the second direction, the plurality of unit structures are arranged in columns along the Y-axis or in a direction parallel to the Y-axis.
[0054] In this embodiment, the period of the unit structures is p=120 um, that is, in the X-axis or Y-axis direction, the distance between any two adjacent unit structures is 120 um.
[0055] In this embodiment, any unit structure such as Figure 2 See Figure 2 The unit structure is a structure with a circular hole in the middle of a square column, which specifically includes a square column part, a base part and a reflective surface. The square column part, the base part and the reflective surface are arranged in sequence along the third direction (equivalent to the Z axis perpendicular to the X axis and the Y axis, that is, the direction perpendicular to the substrate), and the reflective surface is closest to the substrate.
[0056] Reference Figure 2 The height of the square column part of the unit structure is h1=120um, the height of the base part is h2=40um, and the height of the reflecting surface is h3=20um. Both the square column part and the base part are made of high-resistance silicon, and the reflecting surface is made of copper. In this way, the OAM silicon-based metasurface antenna is composed of high-resistance silicon and copper as a whole.
[0057] Reference Figure 2, a cylindrical hollow part is provided inside the square column part, which can be obtained by digging out a cylinder inside the square column part, and the hollow part is equivalent to a circular hole in the square column part. The radius of the bottom surface of the hollow part is R. By changing the radius R of the circular hole, the equivalent refractive index of the unit structure can be changed.
[0058] In this embodiment, refer to Figure 1 Since the unit structures in the metasurface are periodically distributed along the X-axis and the Y-axis respectively, the metasurface can be divided into two channels, the X-axis (first direction) and the Y-axis (second direction). Excitation from the first direction can generate an OAM beam of the +1 mode, and excitation from the second direction can generate an OAM beam of the -1 mode.
[0059] In order to enable the metasurface to generate +1 mode and -1 mode OAM beams, the fisheye lens and the waveguide body have corresponding structures respectively.
[0060] Reference Figure 1 The waveguide body includes two parts, a first silicon waveguide and a second silicon waveguide. The first silicon waveguide and the second silicon waveguide have the same shape, both of which are a silicon conical tip.
[0061] Reference Figure 1 The fisheye lens includes two parts, a first plane Maxwell half fisheye lens and a second plane Maxwell half fisheye lens, and the two parts have the same structure but different directions.
[0062] Taking the first plane Maxwell semi-fisheye lens as an example, its shape is a semicircle, and its outline includes a diameter side and an arc side. The unit structures in the metasurface are periodically distributed along the X-axis and the Y-axis, respectively, so the outline of the metasurface can be a rectangle, specifically a square, which includes four sides, two of which are a first side parallel to the X-axis (first direction) and a second side parallel to the Y-axis (second direction).
[0063] Reference Figure 1 , the side where the diameter edge of the first plane Maxwell half fisheye lens is located is parallel to the X-axis (first direction), and the side where the diameter edge of the first plane Maxwell half fisheye lens is located is connected to the first side of the metasurface. The first silicon waveguide is connected to the side where the arc edge of the first plane Maxwell half fisheye lens is located. Through such a structure, the first silicon waveguide can be used as an energy point source to input energy into the first plane Maxwell half fisheye lens along the Y-axis (second direction), and the first plane Maxwell half fisheye lens uniformly feeds the metasurface along the Y-axis (second direction), thereby exciting the metasurface from the second direction to generate a -1 mode OAM beam.
[0064] Reference Figure 1, the side where the diameter edge of the second plane Maxwell half fisheye lens is located is parallel to the Y axis (second direction), and the side where the diameter edge of the second plane Maxwell half fisheye lens is located is connected to the second side of the metasurface. The second silicon waveguide is connected to the side where the arc edge of the second plane Maxwell half fisheye lens is located. Through such a structure, the second silicon waveguide can be used as an energy point source to input energy into the second plane Maxwell half fisheye lens along the X axis (first direction), and the second plane Maxwell half fisheye lens uniformly feeds the metasurface along the X axis (first direction), thereby exciting the metasurface from the second direction to generate a +1 mode OAM beam.
[0065] In this embodiment, the phase distribution calculation formula of the +1 non-diffraction OAM mode and the -1 non-diffraction OAM mode on the metasurface is:
[0066]
[0067] where ψ +1 , ψ -1 Respectively represent the phase distributions of +1 non-diffraction OAM mode and -1 non-diffraction OAM mode; and represents the spiral phase; r represents the distance between the unit position and the center of the hypersurface, and r0 represents the farthest distance between the unit on the hypersurface and the center of the hypersurface.
[0068] By combining the above phase distribution with the reference wave required by holographic theory, we can obtain the equivalent surface impedance required for the unit structure with coordinates (x, y) on the metasurface to generate the non-diffraction +1 mode and -1 mode:
[0069]
[0070] Z in the formula s represents the equivalent surface impedance that the unit structure needs to provide. M is a modulation parameter used to control the release of metasurface energy. x and y represent the x-axis and y-axis positions of the unit, n is 1 or -1, k0 is, l is 1 or -1, is the spiral phase, X is the average surface impedance of the entire metasurface, n is the effective refractive index of the electromagnetic wave on the entire metasurface, k0 is the wave number of the electromagnetic wave. Since the electromagnetic waves transmitted on the metasurface are generally 306 GHz, n is specifically the effective refractive index of the electromagnetic wave with a frequency of 306 GHz on the entire metasurface, and k0 is specifically the wave number of the electromagnetic wave with a frequency of 306 GHz propagating in a vacuum.
[0071] The unit structure shown above can provide a unit library with different equivalent surface impedances by changing the circular hole radius R, which is then matched with the equivalent surface impedance required by the metasurface, and the required unit structure size is selected to form the final metasurface antenna.
[0072] In this embodiment, the phase distribution of the +1 non-diffraction OAM mode calculated according to formula (3) is shown in Figure 3(a), and the phase distribution of the -1 non-diffraction OAM mode is shown in Figure 3(b); the ideal surface impedance of the metasurface in the X-axis (first direction) is calculated as shown in Figure 4(a), the ideal surface impedance in the Y-axis (second direction) is shown in Figure 4(b), and the ideal surface impedance after the X-axis (first direction) and the Y-axis (second direction) are superimposed is shown in Figure 4(c).
[0073] right Figure 1 The electric field strength and phase distribution of the OAM silicon-based metasurface antenna shown in the figure are simulated when excited from the X and Y directions at 310 GHz. The simulation results are shown in Figure 5(a)-Figure 5(d) As shown. Among them, Figure 5(a) is the electric field intensity distribution diagram of the +1 mode non-diffraction OAM beam obtained by simulation, Figure 5(b) is the phase distribution diagram of the +1 mode non-diffraction OAM beam, Figure 5(c) is the electric field intensity distribution diagram of the -1 mode non-diffraction OAM beam, and Figure 5(d) is the phase distribution diagram of the -1 mode non-diffraction OAM beam.
[0074] according to Figure 3(a)-Figure 5(d) It can be seen from the results that the OAM silicon-based metasurface antenna in this embodiment has a good OAM beam building effect.
[0075] In this embodiment, Figure 1 The OAM silicon-based metasurface antenna shown is fabricated by the following steps:
[0076] S1. Obtain a double-polished intrinsic high-resistance silicon wafer as a substrate;
[0077] S2. Using a cleaning agent to ultrasonically clean the silicon wafer;
[0078] S3. Changing the surface of the silicon wafer to a hydrophilic state;
[0079] S4. Applying photoresist on the front side of the silicon wafer and pre-baking the photoresist;
[0080] S5. exposing and developing the photoresist to transfer the pattern on the mask to the photoresist; the pattern on the mask corresponds to the metasurface and the fisheye lens;
[0081] S6. The developed photoresist is heated to harden the film;
[0082] S7. Etching the silicon wafer to produce a waveguide;
[0083] S8. Plate chromium, copper and gold on the back of the silicon wafer;
[0084] S9. ultrasonically cleaning the silicon wafer using a cleaning agent;
[0085] S10. Remove the photoresist on the silicon wafer using plasma.
[0086] like Figure 6 As shown, steps S1-S10 can be divided into six steps. Specifically, double-polished intrinsic high-resistance silicon (ρ>1000Ωcm, ε r =11.7) as a substrate to make a super surface antenna. First, the silicon wafer is thinned and thinned to a target thickness of 160 microns by deep silicon etching equipment. Then the silicon wafer is ultrasonically cleaned in acetone, isopropanol and deionized water for 5 minutes respectively, and then the silicon wafer is treated with O2 plasma for 2 minutes (Power = 80w) by a plasma cleaner to change the hydrophobic silicon wafer surface to a hydrophilic state. The first step is to evenly coat the silicon wafer with AZ4330 photoresist (3 microns thick) and bake it for 120 seconds on a 100°C heating table. The second step is to expose the photoresist for 10 seconds using a SUSS MABA6 photolithography machine, and develop it for 52 seconds to transfer the pattern on the mask to the photoresist, and heat the developed photoresist on a 120-degree heating table for 5 minutes to harden the film. The third step is to use a deep silicon etching device (Samco RIE-400iPB) to etch the silicon wafer using the Bosch process (170 cycles, etching cycle: 200 / 10sccm SF6 / O2, coil power of 650w, bias power of 120w, cavity pressure of 4Pa, hold for 1.5 seconds. Passivation cycle: 120sccm C4F8, coil power of 1000w, cavity pressure of 1.5Pa, hold for 2 seconds), with an etching depth of 120 microns. In order to etch out the tip of the silicon waveguide, a second etching can be performed. Before etching, the metasurface that does not require secondary etching is protected with glass. The second etching uses a deep silicon etching device (Samco RIE-400iPB) (140 cycles, etching cycle: 100 / 10sccm SF6 / O2, coil power of 600w, bias power of 120w, chamber pressure of 4Pa, hold for 2s. Passivation cycle: 200sccm C4F8, coil power of 1000w, chamber pressure of 4Pa, hold for 2 seconds), and the etching depth is >40 microns. The sixth step is to plate 10nm of chromium, 1000nm of copper and 20nm of gold on the back of the silicon-based metasurface antenna. Finally, ultrasonic cleaning is performed with acetone, isopropanol and deionized water for 1 minute, and then the residual photoresist is removed by plasma cleaning with O2 plasma for 1 minute (Power = 80w). Finally, the finished product shown in Figure 7 (a) is obtained.
[0087] In the finished OAM silicon-based metasurface antenna shown in Figure 7(a), the corresponding structures of each part are shown in Figure 7(b).
[0088] It should be noted that, unless otherwise specified, when a feature is referred to as being "fixed" or "connected" to another feature, it may be directly fixed or connected to the other feature, or it may be indirectly fixed or connected to the other feature. In addition, the descriptions of up, down, left, right, etc. used in the present disclosure are only relative to the relative positional relationship of the components of the present disclosure in the accompanying drawings. The singular forms of "a", "" and "the" used in the present disclosure are also intended to include the plural forms, unless the context clearly indicates other meanings. In addition, unless otherwise defined, all technical and scientific terms used in this embodiment have the same meaning as those generally understood by those skilled in the art. The terms used in the specification of this embodiment are only for describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in this embodiment includes any combination of one or more related listed items.
[0089] It should be understood that, although the term first, second, third etc. may be adopted to describe various elements in the present disclosure, these elements should not be limited to these terms. These terms are only used to distinguish the same type of elements from each other. For example, without departing from the scope of the present disclosure, the first element may also be referred to as the second element, and similarly, the second element may also be referred to as the first element. The use of any and all examples or exemplary language ("for example", "such as" etc.) provided by the present embodiment is only intended to better illustrate embodiments of the present invention, and unless otherwise required, the scope of the present invention will not be limited.
[0090] It should be appreciated that embodiments of the present invention may be implemented or enforced by computer hardware, a combination of hardware and software, or by computer instructions stored in a non-transitory computer-readable memory. The method may be implemented in a computer program using standard programming techniques - including a non-transitory computer-readable storage medium configured with a computer program, wherein the storage medium so configured causes the computer to operate in a specific and predefined manner - according to the methods and drawings described in the specific embodiments. Each program may be implemented in a high-level procedural or object-oriented programming language to communicate with a computer system. However, if desired, the program may be implemented in assembly or machine language. In any case, the language may be a compiled or interpreted language. In addition, the program may be run on a programmed dedicated integrated circuit for this purpose.
[0091] In addition, the operations of the process described in this embodiment may be performed in any suitable order, unless otherwise indicated in this embodiment or otherwise clearly contradicted by the context. The process described in this embodiment (or variations and / or combinations thereof) may be performed under the control of one or more computer systems configured with executable instructions, and may be implemented as a code (e.g., executable instructions, one or more computer programs, or one or more applications) executed on one or more processors in common, by hardware or a combination thereof. A computer program includes a plurality of instructions that may be executed by one or more processors.
[0092] Further, the method can be implemented in any type of computing platform that is operably connected to a suitable computer, including but not limited to a personal computer, a minicomputer, a mainframe, a workstation, a network or distributed computing environment, a separate or integrated computer platform, or in communication with a charged particle tool or other imaging device, etc. Various aspects of the present invention can be implemented in machine-readable code stored on a non-transitory storage medium or device, whether removable or integrated into a computing platform, such as a hard disk, an optical read and / or write storage medium, a RAM, a ROM, etc., so that it can be read by a programmable computer, and when the storage medium or device is read by the computer, it can be used to configure and operate the computer to perform the process described herein. In addition, the machine-readable code, or part thereof, can be transmitted via a wired or wireless network. When such media includes instructions or programs that implement the above steps in conjunction with a microprocessor or other data processor, the invention of this embodiment includes these and other different types of non-transitory computer-readable storage media. When programmed according to the methods and techniques of the present invention, the present invention also includes the computer itself.
[0093] The computer program can be applied to input data to perform the functions of the present embodiment, thereby converting the input data to generate output data stored in a non-volatile memory. The output information can also be applied to one or more output devices such as a display. In a preferred embodiment of the present invention, the converted data represents a physical and tangible object, including a specific visual depiction of the physical and tangible object produced on the display.
[0094] The above are only preferred embodiments of the present invention. The present invention is not limited to the above embodiments. As long as the technical effects of the present invention are achieved by the same means, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention. Within the scope of protection of the present invention, its technical solutions and / or implementation methods may have various modifications and changes.
Claims
1. An OAM silicon-based metasurface antenna, characterized in that: The OAM silicon-based metasurface antenna comprises: Supersurface; A wave conductor; the wave conductor is used to receive input energy; Fisheye lens; the fisheye lens is used to convert the input energy into plane wave energy and uniformly feed the metasurface.
2. The OAM silicon-based metasurface antenna according to claim 1, characterized in that: The metasurface, the fisheye lens and the waveguide body are located on the same plane.
3. The OAM silicon-based metasurface antenna according to claim 1, characterized in that: The metasurface includes a plurality of unit structures, each of which is periodically arranged in a first direction and a second direction, respectively, and the first direction and the second direction are perpendicular to each other.
4. The OAM silicon-based metasurface antenna according to claim 3, characterized in that: The unit structure includes a square column part, a base part and a reflecting surface. A cylindrical hollow part is provided inside the square column part. The square column part, the base part and the reflecting surface are arranged in sequence along a third direction, and the third direction is perpendicular to the first direction and the second direction.
5. The OAM silicon-based metasurface antenna according to claim 4, characterized in that: The square column part and the base part are made of high-resistance silicon material, and the reflective surface is made of copper material.
6. The OAM silicon-based metasurface antenna according to claim 4, characterized in that: The equivalent surface impedance of the metasurface is: Among them, Z s is the equivalent surface impedance provided by the unit structure at position (x, y), x is the position of the unit structure in the first direction, y is the position of the unit structure in the second direction, j is an imaginary unit, M is a modulation parameter, r is the distance between the unit structure at position (x, y) and the center of the metasurface, r0 is the farthest distance between all the unit structures of the metasurface and the center of the metasurface, n is the effective refractive index of the electromagnetic wave on the entire metasurface, k0 is the wave number of the electromagnetic wave, l is 1 or -1, is the spiral phase, and X is the average surface impedance of the entire metasurface.
7. The OAM silicon-based metasurface antenna according to any one of claims 3 to 6, characterized in that: The fisheye lens comprises a first plane Maxwell half fisheye lens and a second plane Maxwell half fisheye lens; The side where the diameter edge of the first plane Maxwell half fisheye lens is located is parallel to the first direction, and the side where the diameter edge of the first plane Maxwell half fisheye lens is located is connected to the first edge of the metasurface; The side where the diameter edge of the second plane Maxwell half fisheye lens is located is parallel to the second direction, and the side where the diameter edge of the second plane Maxwell half fisheye lens is located is connected to the second edge of the metasurface.
8. The OAM silicon-based metasurface antenna according to claim 7, characterized in that: The waveguide body includes a first silicon waveguide and a second silicon waveguide; The first silicon waveguide is connected to the side where the arc edge of the first planar Maxwell semi-fisheye lens is located; The second silicon waveguide is connected to the side where the arc edge of the second planar Maxwell semi-fisheye lens is located.
9. The OAM silicon-based metasurface antenna according to any one of claims 1 to 6, characterized in that: The OAM silicon-based metasurface antenna further comprises: Substrate; the metasurface, the fisheye lens and the waveguide are integrated on the substrate.
10. The OAM silicon-based metasurface antenna according to claim 9, characterized in that: The OAM silicon-based metasurface antenna is manufactured by the following steps: Obtain a double-polished intrinsic high-resistance silicon wafer as a substrate; Ultrasonic cleaning of silicon wafers using a detergent; Changing the surface of the silicon wafer to a hydrophilic state; Apply photoresist on the front side of the silicon wafer and pre-bake the photoresist; Expose and develop the photoresist to transfer the pattern on the mask to the photoresist; The pattern on the mask corresponds to the metasurface and the fisheye lens; Heating and hardening the developed photoresist; Etching the silicon wafer to produce the waveguide body; The back side of the silicon wafer is plated with chrome, copper, and gold; Ultrasonic cleaning of silicon wafers using a cleaning agent; Use plasma to remove photoresist from silicon wafers.