Terahertz binary encoder with double-frequency amplitude independently regulated and controlled

Abstract

The invention discloses a terahertz binary encoder with double-frequency amplitude independently regulated and controlled. The terahertz binary encoder is composed of a high-resistance silicon layer, a silicon dioxide layer, a common ground electrode and a frequency control structure. The silicon dioxide layer and the high-resistance silicon layer are stacked, and the lower surface of the silicon dioxide layer is attached to the upper surface of the high-resistance silicon layer; the frequency control structure is stacked on the upper surface of the silicon dioxide layer, and the common ground electrode is stacked on the lower surface of the high-resistance silicon layer. The frequency control structure comprises a surface periodic structure and a lead-out structure. The transmission unit of the surface periodic structure is composed of two C-like metal patches, two long-strip-shaped metal patches and two long-strip-shaped graphene patches. And the two lead-out structures are respectively connected with the two C-like metal patches. According to the invention, terahertz wave frequency selection, modulation and frequency domain coding can be realized on the same chip, and theoretical support and technical reference are provided for research and development of integrated, multifunctional and miniaturized terahertz communication devices.

Description

Technical Field

[0001] The present invention relates to the technical field of terahertz technology, and particularly relates to a terahertz binary encoder with independent regulation of dual-frequency amplitude. Background Art

[0002] With the emergence and rapid development of technologies such as the Internet of Things, big data, and artificial intelligence, human society is about to enter the intelligent era. The data volume of user digital terminals and various services will increase explosively, posing new requirements for the capacity and rate of communication systems. In the past decade, the wireless data transmission rate has doubled every eighteen months. It is expected that in the next decade, the wireless data transmission rate will exceed 100 Gbit / s, and the existing wireless communication systems will simply not be able to meet such high data transmission rates. Terahertz communication, which can effectively alleviate the increasingly tense spectrum resources and the capacity and rate limitations of current wireless communication systems, has become a frontier direction and research hotspot in broadband wireless communication. In point-to-point broadband terahertz wireless communication, especially in the field of terahertz secure communication, it is necessary to perform frequency-domain coding on terahertz waves, that is, convert terahertz waves into binary digits 0 or 1 for transmission in the frequency domain. Therefore, the research and development of a terahertz binary encoder with independent regulation of dual-frequency amplitude is of great significance for promoting the integration, multi-function, and miniaturization of terahertz communication devices. Summary of the Invention

[0003] The problem to be solved by the present invention is that the existing terahertz wave transmission control devices cannot yet achieve independent regulation of dual-frequency amplitude and frequency-domain coding, and a terahertz binary encoder with independent regulation of dual-frequency amplitude is provided.

[0004] To solve the above problems, the present invention is realized through the following technical solutions:

[0005] A terahertz binary encoder with independent amplitude regulation for dual frequencies, comprising an encoder body, which is composed of a high-resistance silicon layer, a silicon dioxide layer, a common ground electrode, and a frequency control structure; the silicon dioxide layer and the high-resistance silicon layer are stacked, and the lower surface of the silicon dioxide layer is attached to the upper surface of the high-resistance silicon layer; the frequency control structure is stacked on the upper surface of the silicon dioxide layer, and the common ground electrode is stacked on the lower surface of the high-resistance silicon layer; the frequency control structure includes a surface periodic structure and a lead-out structure; the surface periodic structure is in the middle of the frequency control structure and is composed of a plurality of transmission units arranged in a regular matrix; each transmission unit is composed of 4 metal patches and 2 graphene patches; the 4 metal patches are respectively an upper metal bar, a low-frequency metal patch, a high-frequency metal patch, and a lower metal bar made of metal materials; the 2 graphene patches are respectively a short graphene patch and a long graphene patch made of graphene materials; the upper metal bar and the lower metal bar are both horizontally extending strips and are respectively located at the upper and lower parts of the transmission unit; the low-frequency metal patch and the high-frequency metal patch are both C-shaped and are respectively located on the upper and lower sides of the middle of the transmission unit; the opening of the low-frequency metal patch faces the direction of the upper metal bar, and the opening of the high-frequency metal patch faces the direction of the lower metal bar; the opening gap of the low-frequency metal patch is smaller than the opening gap of the high-frequency metal patch; the short graphene patch is arranged at the opening gap of the low-frequency metal patch, and its two ends are connected to the two ends of the low-frequency metal patch; the long graphene patch is arranged at the opening gap of the high-frequency metal patch, and its two ends are connected to the two ends of the high-frequency metal patch; the lead-out structure is located on the left and right sides of the surface periodic structure and is composed of 2 electrode patches; the 2 electrode patches are respectively a low-frequency electrode patch and a high-frequency electrode patch made of metal materials; the low-frequency electrode patch and the high-frequency electrode patch are both comb-shaped, and the number of their teeth is the same as the number of rows of the transmission units; each tooth of the low-frequency electrode patch is connected to the low-frequency metal patch of one row of transmission units, and each tooth of the high-frequency electrode patch is connected to the high-frequency metal patch of one row of transmission units; the common ground electrode is a closed ring made of metal materials; the low-frequency electrode patch is connected to the positive pole of a DC regulated power supply through a switch, the high-frequency electrode patch is connected to the positive pole of another DC regulated power supply through another switch, and the common ground electrode is connected to the negative poles of the above two DC regulated power supplies.

[0006] In the above solution, the column spacing between two adjacent transmission units in the same row is zero, and the row spacing between two adjacent transmission units in the same column is zero.

[0007] In the above solution, the line width and line length of the upper metal bar are equal to the line width and line length of the lower metal bar.

[0008] In the above solution, the length, width, and line width of the low-frequency metal patch are equal to the length, width, and line width of the high-frequency metal patch.

[0009] In the above solution, the line width of the short graphene patch is smaller than the line width of the long graphene patch.

[0010] In the above solution, the common ground electrode is in a circular ring shape.

[0011] In the above solution, the center of the surface periodic structure is vertically opposite to the center of the common ground electrode.

[0012] Compared with the prior art, the present invention can realize terahertz wave frequency selection, modulation and frequency domain coding on the same chip, providing theoretical support and technical reference for the research and development of integrated, multifunctional and miniaturized terahertz communication devices. Description of the Drawings

[0013] Figure 1 It is a schematic three-dimensional structure diagram of a terahertz binary encoder with independent regulation of the amplitudes of two frequencies;

[0014] Figure 2 is Figure 1 the top view of;

[0015] Figure 3 It is a schematic structure diagram of the transmission unit;

[0016] Figure 4 is Figure 1 the bottom view of;

[0017] Figure 5 (a) It is a schematic curve diagram of the terahertz wave transmittance of the present invention varying with the Fermi level of the low-frequency graphene patch in the low-frequency metal patch, Figure 5 (b) It is a schematic curve diagram of the terahertz wave transmittance of the present invention varying with the Fermi level of the high-frequency graphene patch in the high-frequency metal patch.

[0018] Figure 6 (a) It is the terahertz wave transmission spectrum of the "11" state of the present invention, Figure 6 (b) It is the terahertz wave transmission spectrum of the "10" state of the present invention, Figure 6 (c) It is the terahertz wave transmission spectrum of the "01" state of the present invention, Figure 6 (d) It is the terahertz wave transmission spectrum of the "00" state of the present invention.

[0019] Reference numerals in the figures: 1 - common ground electrode; 2 - high-resistance silicon layer; 3 - silicon dioxide layer; 4 - frequency control structure; 41 - upper metal rod; 42 - high-frequency metal patch; 43 - lower metal rod; 44 - low-frequency metal patch; 45 - long graphene patch; 46 - short graphene patch, 47 - electrode patch. Detailed Embodiments

[0020] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to specific examples and the accompanying drawings. It should be noted that the directional terms mentioned in the examples, such as "upper", "lower", "middle", "left", "right", "front", "rear", etc., are only with reference to the directions in the accompanying drawings. Therefore, the directions used are only for illustration and not for limiting the protection scope of the present invention.

[0021] A terahertz binary encoder with independent regulation of dual-frequency amplitudes is composed of a high-resistivity silicon layer 2, a silicon dioxide layer 3, a common ground electrode 1, and a frequency control structure 4, as Figure 1 shown. The silicon dioxide layer 3 and the high-resistivity silicon layer 2 are stacked, and the lower surface of the silicon dioxide layer 3 is in contact with the upper surface of the high-resistivity silicon layer 2. The frequency control structure 4 is stacked on the upper surface of the silicon dioxide layer 3, and the common ground electrode 1 is stacked on the lower surface of the high-resistivity silicon layer 2.

[0022] The silicon dioxide layer 3 is made of silicon dioxide material, and the high-resistivity silicon layer 2 is made of high-resistivity silicon material. The shapes of the high-resistivity silicon layer 2 and the silicon dioxide layer 3 can be circular, square, polygonal, etc., as long as they can accommodate the common ground electrode 1 and the frequency control structure 4. In a preferred embodiment of the present invention, both the high-resistivity silicon layer 2 and the silicon dioxide layer 3 are rectangular, the thickness of the high-resistivity silicon layer 2 is 500 μm, and the thickness of the silicon dioxide layer 3 is 200 nm.

[0023] The frequency control structure 4 includes a surface periodic structure and a lead-out structure, as Figure 2 shown. The surface periodic structure is in the middle of the frequency control structure 4 and is composed of a plurality of transmission units arranged in a regular matrix. The column pitch between two adjacent transmission units in the same row is zero, and the row pitch between two adjacent transmission units in the same column is zero. Each transmission unit is composed of 4 metal patches and 2 graphene patches, as Figure 3As shown. In a preferred embodiment of the present invention, the thickness of the metal patches is 200 nm, and the thickness of the graphene patches is 0.34 nm. The four metal patches are respectively an upper metal rod 41, a low-frequency metal patch 44, a high-frequency metal patch 42, and a lower metal rod 43 made of a metal material. The upper metal rod 41, the low-frequency metal patch 44, the high-frequency metal patch 42, and the lower metal rod 43 are arranged at intervals from top to bottom. The two graphene patches are respectively a short graphene patch 46 and a long graphene patch 45 made of graphene material. The line width and line length of the upper metal rod 41 are equal to the line width and line length of the lower metal rod 43. By adjusting the width of the metal rod, the coupling strength of the two transmission peaks of the device can be changed. The upper metal rod 41 and the lower metal rod 43 are both horizontally extending long strips and are respectively located at the upper and lower parts of the transmission unit. The low-frequency metal patch 44 and the high-frequency metal patch 42 are both C-shaped and are respectively located on the upper side and the lower side of the middle part of the transmission unit. In a preferred embodiment of the present invention, the low-frequency metal patch 44 and the high-frequency metal patch 42 are square C-shaped, that is, both are square annular structures with an opening in the middle of one of their sides. The low-frequency metal patch 44 and the high-frequency metal patch 42 are arranged back to back. The opening of the low-frequency metal patch 44 faces the direction of the upper metal rod 41, and the opening of the high-frequency metal patch 42 faces the direction of the lower metal rod 43. Since the opening gap of the metal patch is proportional to the resonant frequency of the encoder, the wider the gap, the higher the transmission frequency; the lower the gap, the lower the transmission frequency. Therefore, the opening gap of the low-frequency metal patch 44 is smaller than the opening gap of the high-frequency metal patch 42. In a preferred embodiment of the present invention, the opening size of the low-frequency metal patch 44 is 40 μm, and its corresponding high-frequency resonant frequency is 0.85 THz. The opening size of the high-frequency metal patch 42 is 60 μm, and its corresponding high-frequency resonant frequency is 1.14 THz. The length, width, and line width of the low-frequency metal patch 44 are equal to the length, width, and line width of the high-frequency metal patch 42. The length of the low-frequency metal patch 44 and the high-frequency metal patch 42 is equal to the length of the upper metal rod 41 and the lower metal rod 43. The short graphene patch 46 is arranged at the opening gap of the low-frequency metal patch 44, and its two ends are connected to the two ends of the low-frequency metal patch 44 to close the low-frequency metal patch 44. The long graphene patch 45 is arranged at the opening gap of the high-frequency metal patch 42, and its two ends are connected to the two ends of the high-frequency metal patch 42 to close the high-frequency metal patch 42. To make Figure 6 (a) the amplitudes of the two transmission peaks the same height, the line width of the short graphene patch 46 is greater than the line width of the long graphene patch 45. In a preferred embodiment of the present invention, the line width of the short graphene patch 46 is set to 2 μm, and the line width of the long graphene patch 45 is set to 3 μm.

[0024] The lead-out structure is located on the left and right sides of the surface periodic structure and consists of two electrode patches 47. The two electrode patches 47 are respectively a low-frequency electrode patch and a high-frequency electrode patch made of a metal material. Both the low-frequency electrode patch and the high-frequency electrode patch are comb-shaped, and the number of their comb teeth is the same as the number of rows of the transmission units. Each comb tooth of the low-frequency electrode patch is connected to the low-frequency metal patch 44 of one row of the transmission units, and each comb tooth of the high-frequency electrode patch is connected to the high-frequency metal patch 42 of one row of the transmission units.

[0025] The common ground electrode 1 is a closed ring made of a metal material, such as Figure 4 shown. In a preferred embodiment of the present invention, the common ground electrode 1 is circular, and the thickness of the common ground electrode 1 is 200 nm. The center of the common ground electrode 1 and the center of the surface periodic structure can be slightly offset in the vertical direction. However, in order to uniformly apply electricity to graphene, in a preferred embodiment of the present invention, the center of the common ground electrode 1 and the center of the surface periodic structure are vertically opposite, that is, the perpendicular bisector of the common ground electrode 1 coincides with the perpendicular bisector of the entire surface periodic structure.

[0026] During use, the terahertz beam will enter perpendicularly to the surface of the encoder from directly above the encoder (i.e., on the side of the frequency control structure 4). In order to allow the terahertz beam to pass through without obstruction, the area covered by the surface periodic structure and the area covered by the inner ring of the common ground electrode 1 are both larger than the area of the terahertz beam spot irradiated on the encoder. In a preferred embodiment of the present invention, the areas covered by the surface periodic structure and the inner ring of the common ground electrode 1 are both 1.5 to 2.5 times the area of the terahertz beam spot.

[0027] The low-frequency electrode patch is connected to the positive pole of a DC regulated power supply via a switch, the high-frequency electrode patch is connected to the positive pole of another DC regulated power supply via another switch, and the common ground electrode 1 is connected to the negative poles of the above two DC regulated power supplies. In a preferred embodiment of the present invention, the voltage of the DC regulated power supply is 0 V to 30 V. When the switch of a certain electrode patch 47 (low-frequency electrode patch or high-frequency electrode patch) is turned off, all the metal patches of the same type (low-frequency metal patch 44 or high-frequency metal patch 42) of the transmission units connected thereto are powered off, and the graphene patch (short graphene patch 46 or long graphene patch 45) at the opening of the metal patch (low-frequency metal patch 44 or high-frequency metal patch 42) exhibits a low Fermi level. When the switch of a certain electrode patch 47 (low-frequency electrode patch or high-frequency electrode patch) is turned on, all the metal patches of the same type (low-frequency metal patch 44 or high-frequency metal patch 42) of the transmission units connected thereto are powered on, and the graphene patch (short graphene patch 46 or long graphene patch 45) at the opening of the metal patch (low-frequency metal patch 44 or high-frequency metal patch 42) exhibits a high Fermi level.

[0028] When not powered on, the low-frequency graphene patch and the low-frequency metal patch 44 can be equivalent to an LC resonant circuit. After power is turned on, the Fermi level of graphene is adjusted to increase its carrier concentration. At this time, the LC resonant circuit structure transforms into an RLC circuit, that is, after the device is applied with a voltage, a current opposite to that on the metal patch appears on the graphene, thereby weakening the LC resonance on the metal patch and causing a significant decrease in the amplitude of the low-frequency transmission peak, as Figure 5 (a) shows.

[0029] Similarly, when not powered on, the high-frequency graphene patch and the long metal patch can be equivalent to an LC resonant circuit. After power is turned on, the Fermi level of graphene is adjusted to increase its carrier concentration. At this time, the LC resonant circuit structure transforms into an RLC circuit, that is, after the device is applied with a voltage, a current opposite to that on the metal patch appears on the graphene, thereby weakening the LC resonance on the metal patch and causing a significant decrease in the amplitude of the high-frequency transmission peak, as Figure 5 (b) shows.

[0030] In addition, since the upper metal rod 41 and the lower metal rod 43 well suppress the coupling between the high-frequency transmission peak and the low-frequency transmission peak, thereby realizing the dual-frequency independent regulation function, which can also be called frequency selection modulation.

[0031] The encoder of the present invention has the following 4 encoding states, namely 11, 01, 10, 00:

[0032] When neither the low-frequency electrode patch nor the high-frequency electrode patch is powered on, both the low-frequency transmission amplitude and the high-frequency transmission amplitude of the encoder are high transmission peaks, corresponding to the binary code 11, as Figure 6 (a) shows.

[0033] When the low-frequency electrode patch is not powered on and the high-frequency electrode patch is powered on, the low-frequency transmission amplitude of the encoder is a high transmission peak and the high-frequency transmission amplitude is a low transmission peak, corresponding to the binary code 10, as Figure 6 (b) shows.

[0034] When the low-frequency electrode patch is powered on and the high-frequency electrode patch is not powered on, the low-frequency transmission amplitude of the encoder is a low transmission peak and the high-frequency transmission amplitude is a high transmission peak, corresponding to the binary code 01, as Figure 6 (c) shows.

[0035] When both the low-frequency electrode patch and the high-frequency electrode patch are powered on, both the low-frequency transmission amplitude and the high-frequency transmission amplitude of the encoder are low transmission peaks, corresponding to the binary code 00, as Figure 6 (d) shows.

[0036] It should be noted that although the embodiments described above of the present invention are illustrative, they are not a limitation of the present invention. Therefore, the present invention is not limited to the above specific embodiments. Without departing from the principle of the present invention, any other embodiments obtained by those skilled in the art under the inspiration of the present invention are deemed to be within the protection scope of the present invention.

Claims

1. A terahertz binary encoder with independent amplitude regulation for dual frequencies, comprising an encoder body, characterized in that, The encoder body is composed of a high-resistance silicon layer (2), a silicon dioxide layer (3), a common ground electrode (1), and a frequency control structure (4); the silicon dioxide layer (3) and the high-resistance silicon layer (2) are stacked, and the lower surface of the silicon dioxide layer (3) is in contact with the upper surface of the high-resistance silicon layer (2); the frequency control structure (4) is stacked on the upper surface of the silicon dioxide layer (3), and the common ground electrode (1) is stacked on the lower surface of the high-resistance silicon layer (2). The frequency control structure (4) includes a surface periodic structure and a lead-out structure. The surface periodic structure is in the middle of the frequency control structure (4) and is composed of a plurality of transmission units arranged in a regular matrix; each transmission unit is composed of 4 metal patches and 2 graphene patches; the 4 metal patches are respectively an upper metal rod (41) made of a metal material, a low-frequency metal patch (44), a high-frequency metal patch (42), and a lower metal rod (43); the 2 graphene patches are respectively a short graphene patch (46) and a long graphene patch (45) made of graphene material; both the upper metal rod (41) and the lower metal rod (43) are horizontally extending strips and are respectively located at the upper and lower parts of the transmission unit; both the low-frequency metal patch (44) and the high-frequency metal patch (42) are C-shaped and are respectively located on the upper and lower sides of the middle of the transmission unit; the opening of the low-frequency metal patch (44) faces the direction of the upper metal rod (41), and the opening of the high-frequency metal patch (42) faces the direction of the lower metal rod (43); the opening gap of the low-frequency metal patch (44) is smaller than the opening gap of the high-frequency metal patch (42). The short graphene patch (46) is arranged at the opening gap of the low-frequency metal patch (44), and its two ends are connected to the two ends of the low-frequency metal patch (44); the long graphene patch (45) is arranged at the opening gap of the high-frequency metal patch (42), and its two ends are connected to the two ends of the high-frequency metal patch (42). The lead-out structure is located on the left and right sides of the surface periodic structure and is composed of 2 electrode patches (47); the 2 electrode patches (47) are respectively a low-frequency electrode patch and a high-frequency electrode patch made of a metal material; both the low-frequency electrode patch and the high-frequency electrode patch are comb-shaped, and the number of teeth of both is the same as the number of rows of the transmission units; each tooth of the low-frequency electrode patch is connected to the low-frequency metal patch (44) of one row of transmission units, and each tooth of the high-frequency electrode patch is connected to the high-frequency metal patch (42) of one row of transmission units. The common ground electrode (1) is a closed ring made of a metal material; the low-frequency electrode patch is connected to the positive pole of a DC regulated power supply through a switch, the high-frequency electrode patch is connected to the positive pole of another DC regulated power supply through another switch, and the common ground electrode (1) is connected to the negative poles of the above two DC regulated power supplies.

2. The terahertz binary encoder with independent regulation of dual-frequency amplitude according to claim 1 is characterized in that The column spacing between two adjacent transmission units in the same row is zero, and the row spacing between two adjacent transmission units in the same column is zero.

3. A terahertz binary encoder with independent regulation of dual-frequency amplitudes according to claim 1, characterized in that, The line width and line length of the upper metal rod (41) are equal to the line width and line length of the lower metal rod (43).

4. A terahertz binary encoder with independent amplitude regulation for dual frequencies according to claim 1, characterized in that The length, width, and line width of the low-frequency metal patch (44) are equal to the length, width, and line width of the high-frequency metal patch (42).

5. A terahertz binary encoder with independent amplitude regulation for dual frequencies according to claim 1, characterized in that, The line width of the short graphene patch (46) is smaller than that of the long graphene patch (45).

6. A terahertz binary encoder with independent amplitude regulation for dual frequencies according to claim 1, characterized in that, The common ground electrode (1) is in a circular ring shape.

7. A terahertz binary encoder with independent amplitude regulation for dual frequencies according to claim 1, characterized in that, The center of the surface periodic structure is vertically opposite to the center of the common ground electrode (1).

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