A topological insulator waveguide suitable for microstrip transmission lines

Abstract

The present invention discloses a topological insulator waveguide suitable for microstrip transmission lines, comprising: a valley topological insulator structure and a microstrip transmission line structure; the microstrip transmission line structure is connected to the valley topological insulator structure; the valley topological insulator structure comprises two topological units, each of which is composed of a plurality of quasi-periodic valley topological insulator unit arrays with rotational symmetry, the valley topological insulator units in the two topological units are in different directions, the valley topological insulator units in the topological units are interconnected, and the adjacent valley topological insulator units of the two topological units are interconnected, and the connecting boundary line is used to propagate electromagnetic waves of topological edge states; the microstrip transmission line structure is used to impedance match and connect the valley topological insulator structure and the user end respectively. The invention can realize direct matching of the topological insulator waveguide with the traditional microwave transmission line system, avoiding the matching structure with large area and complex design.

Description

Technical Field

[0001] The invention relates to the field of microwave devices, and in particular to a topological insulator waveguide suitable for a microstrip transmission line. Background Art

[0002] Topological insulators have a robust topological edge state propagation mode. The topological insulating waveguides designed based on them also have special electromagnetic edge states, which can still propagate stably at local defects and sharp edges of the waveguide, and have good application prospects in microwave integrated circuits.

[0003] However, the application of topological insulating waveguides in microwave integrated circuits has the following technical problems:

[0004] There is a mismatch between topological insulating waveguides and traditional microwave transmission line systems. Although some solutions can achieve matching between the two, they usually require a large and complex matching structure. Therefore, it is of great significance to design a topological insulating waveguide that can directly match the traditional microwave transmission line system.

[0005] In addition, as an important application of topological insulator waveguides, it is difficult to achieve flexible coupling efficiency control in the design of topological insulator directional couplers. Therefore, the design of topological insulator directional couplers that can flexibly control the direct pass and coupling coefficients between ports has important application prospects. Summary of the invention

[0006] The purpose of the present invention is to provide a topological insulator waveguide suitable for microstrip transmission lines. The microstrip transmission line structure of the invention is directly connected to the valley topological insulator structure. The invention also provides a directional coupler application of the topological insulator waveguide, which can adjust the geometric relationship and relative position of the two units of the topological insulator waveguide to adjust the required port-to-port directivity and coupling coefficient.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A topological insulator waveguide suitable for a microstrip transmission line comprises: a valley topological insulator structure and a microstrip transmission line structure; the microstrip transmission line structure is connected to the valley topological insulator structure;

[0009] The valley topological insulator structure includes two topological units, each of which is composed of a plurality of quasi-periodic valley topological insulator unit arrays with rotational symmetry, the valley topological insulator units in the two topological units are in different directions, the valley topological insulator units in the topological units are interconnected, and the adjacent valley topological insulator units of the two topological units are interconnected, and the connecting boundary line is used to propagate electromagnetic waves of topological edge states;

[0010] The microstrip transmission line structure is used to perform impedance matching and connection on the valley topological insulator structure and the user end respectively.

[0011] As a further improvement of the present invention, the valley topological insulator unit comprises: a regular hexagonal dielectric layer, a hexagonal metal patch and a metal fine wire;

[0012] The hexagonal metal patch is arranged on the top surface of the regular hexagonal dielectric layer;

[0013] Six thin metal wires are led out from the hexagonal metal patch and radiate to the edge of the regular hexagonal dielectric layer.

[0014] As a further improvement of the present invention, the midpoint of the side length of the hexagonal metal patch is arranged corresponding to the vertex of the regular hexagonal dielectric layer, and the metal fine wire connects the midpoint of the side length of the hexagonal metal patch and the vertex of the regular hexagonal dielectric layer.

[0015] As a further improvement of the present invention, one end of the microstrip transmission line structure is directly connected to the metal thin wire of the valley topological insulator unit.

[0016] As a further improvement of the present invention, the boundary line between the two topological units is a straight line or a broken line bent at any angle.

[0017] As a further improvement of the present invention, the topological insulator waveguide is manufactured by a printed circuit board process, an additive manufacturing process or a laser etching process.

[0018] As a further improvement of the present invention, when each topological unit is composed of multiple parts, the topological units of the multiple parts are centrally symmetrically arranged.

[0019] As a further improvement of the present invention, both topological units include two parts, the four parts are centrally symmetrical, and form four microstrip line ports, which are:

[0020] The first microstrip line port is the input port of the topological insulator directional coupler;

[0021] The second microstrip line port is a through port of the topological insulator directional coupler;

[0022] The third microstrip line port is a coupling port of the topological insulator directional coupler;

[0023] The fourth microstrip line port is an isolation port of the topological insulator directional coupler.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] A topological insulator waveguide suitable for microstrip transmission lines of the present invention comprises a valley topological insulator structure and a microstrip transmission line structure, wherein the microstrip transmission line structure is directly connected to the valley topological insulator structure; the valley topological insulator structure is composed of a large number of quasi-periodic units with rotational symmetry, and is used to propagate electromagnetic waves of topological edge states; the microstrip transmission line structure is used to impedance match and connect the valley topological insulator structure and the user end respectively. The electromagnetic waves of the topological edge states propagate along the junction of the two units. The invention can realize direct matching of the topological insulator waveguide with the traditional microwave transmission line system, avoiding the matching structure with a large area and complex design. The present invention provides a topological insulator waveguide directly suitable for microstrip transmission lines in view of the mismatch between the topological insulating waveguide and the traditional microwave transmission line system. The topological insulator waveguide directly suitable for microstrip transmission lines provided by the present invention greatly reduces the complexity of matching the topological insulator waveguide with the traditional microwave transmission line system. The present invention is oriented to the directional coupler application of the topological insulating waveguide, and provides a topological insulator coupler scheme that can flexibly adjust the direct pass and coupling coefficient between ports. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of a topological insulator waveguide suitable for a microstrip transmission line according to an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the structure of a valley topological insulator unit according to an embodiment of the present invention;

[0028] Figure 3 Schematic diagram of two mirror-symmetric valley topological insulator units A and B of the embodiment of the present invention;

[0029] Figure 4 is an S parameter curve of the topological insulator waveguide described in an embodiment of the present invention;

[0030] Figure 5 A schematic diagram of an application of a directional coupler of a topological insulator waveguide according to an embodiment of the present invention;

[0031] Figure 6 This is an S-parameter curve of the topological insulator directional coupler described in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0033] like Figure 1 As shown, the embodiment of the present invention discloses a topological insulator waveguide suitable for a microstrip transmission line, comprising: a valley topological insulator structure 101 and a microstrip transmission line structure 102; the microstrip transmission line structure 102 is connected to the valley topological insulator structure 101;

[0034] Specifically, the valley topological insulator structure 101 includes two topological units, each of which is composed of a plurality of quasi-periodic valley topological insulator unit arrays with rotational symmetry, the valley topological insulator units in the two topological units are in different directions, the valley topological insulator units in the topological units are interconnected, and the adjacent valley topological insulator units of the two topological units are interconnected, and the connecting boundary line is used to propagate electromagnetic waves of topological edge states;

[0035] A planar valley topological insulator structure 101 and a microstrip transmission line structure 102; the microstrip transmission line structure 102 is directly connected to the valley topological insulator structure 101;

[0036] The valley topological insulator structure 101 is composed of a large number of quasi-periodic units with rotational symmetry, and is used to propagate electromagnetic waves of topological edge states;

[0037] The microstrip transmission line structure 102 is used to perform impedance matching and connection on the valley topological insulator structure 101 and the user end respectively.

[0038] Specifically, Figure 2 As shown, the valley topological insulator unit includes: a regular hexagonal dielectric layer 201, a hexagonal metal patch 202 and six metal thin wires 203;

[0039] The hexagonal metal patch 202 is arranged on the top surface of the regular hexagonal dielectric layer 201;

[0040] Six metal thin wires 203 are led out from the hexagonal metal patch 202 and radiate to the edge of the unit structure.

[0041] The microstrip transmission line structure 102 is used to perform impedance matching and connection on the valley topological insulator structure 101 and the user end respectively.

[0042] Furthermore, the midpoint of the side length of the hexagonal metal patch 202 is arranged corresponding to the vertex of the regular hexagonal dielectric layer 201 , and the metal fine wire 203 connects the midpoint of the side length of the hexagonal metal patch 202 and the vertex of the regular hexagonal dielectric layer 201 .

[0043] When each topological unit consists of multiple parts, the topological units of the multiple parts are centrally symmetrically arranged.

[0044] Furthermore, Figure 3As shown, the topological insulator waveguide is composed of two mirror-symmetrical units, a first part A301 and a second part B302, and the electromagnetic wave of the topological edge state propagates along the junction of the two units.

[0045] The boundary line between the two units of the topological insulator waveguide is a straight line or a broken line bent at any angle;

[0046] All units of the topological insulator waveguide are complete or partially defective. Furthermore, the boundary line between the two units of the topological insulator waveguide can be a straight line or a broken line bent at any angle; all units of the topological insulator waveguide are complete or partially defective. The microstrip lines at both ends of the topological insulator waveguide still have a good transmission coefficient.

[0047] The topological insulator waveguide is made by a printed circuit board process, an additive manufacturing process or a laser etching process. In this embodiment, the topological insulator waveguide suitable for a microstrip transmission line is made by a printed circuit board process.

[0048] Furthermore, Figure 4 As shown, the microstrip lines at both ends of the topological insulator waveguide have good transmission coefficients.

[0049] The impedance characteristics and electric field modes of the microstrip transmission line structure and the topological insulator structure are close and easy to match; one end of the microstrip transmission line structure 102 is directly connected to the metal thin wire 203 of the valley topological insulator unit.

[0050] The size of the topological insulator waveguide can be scaled proportionally to work in different electromagnetic wave frequency ranges.

[0051] For example Figure 5 As shown, both topology units include two parts, the four parts are centrally symmetrical, and form four microstrip line ports.

[0052] like Figure 5 As shown, the present invention also provides a directional coupler application of a topological insulator waveguide, comprising:

[0053] A first microstrip line port 11, a second microstrip line port 12, a third microstrip line port 13, a fourth microstrip line port 14 and a topological insulator waveguide directly connected to the four microstrip lines.

[0054] The first microstrip line port 11 is an input port of the topological insulator directional coupler;

[0055] The second microstrip line port 12 is a through port of the topological insulator directional coupler;

[0056] The third microstrip line port 13 is a coupling port of the topological insulator directional coupler;

[0057] The fourth microstrip line port 14 is an isolation port of the topological insulator directional coupler.

[0058] Furthermore, Figure 6 As shown, the topological insulator waveguide directional coupler has good input port matching, good isolation port isolation, and equal power distribution between the through and coupled ports.

[0059] Furthermore, the geometric relationship and relative positions of the two units of the topological insulator waveguide A and B are adjusted to adjust the required direct-through and coupling coefficients between ports.

[0060] Figure 4 It is the S parameter curve of the topological insulator waveguide described in the embodiment of the present invention; in the frequency range of 13.5-14.5 GHz, the transmission coefficient between the input and output ports of the topological insulator waveguide is greater than -1.3 dB, and the reflection coefficient of the input port is less than -10 dB, indicating that the topological insulator waveguide described in the embodiment of the present invention has good performance.

[0061] Figure 6 The topological insulator directional coupler S parameter curve of the embodiment of the present invention. At the operating frequency of 14GHz of the embodiment of the present invention, the reflection coefficient of the input port 1 of the topological insulator directional coupler is less than -18dB, the output port 2 and port 3 have an equal power transmission coefficient of about -5dB respectively, and the transmission coefficient of the isolated port 4 is less than -21dB. The topological insulator directional coupler described in the embodiment of the present invention has good input matching, the two output ports have the same power transmission coefficient and the isolation port has high isolation.

[0062] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A topological insulator waveguide suitable for a microstrip transmission line, characterized in that: include: A valley topological insulator structure (101) and a microstrip transmission line structure (102); the microstrip transmission line structure (102) is connected to the valley topological insulator structure (101); The valley topological insulator structure (101) comprises two topological units, each of which is composed of a plurality of quasi-periodic valley topological insulator units arranged in an array with rotational symmetry, the valley topological insulator units in the two topological units are in different directions, the valley topological insulator units in the topological units are interconnected, and the adjacent valley topological insulator units of the two topological units are interconnected, and the connecting boundary line is used to propagate electromagnetic waves of topological edge states; The microstrip transmission line structure (102) is used to respectively perform impedance matching and connection on the valley topological insulator structure (101) and the user end; The valley topological insulator unit comprises: a regular hexagonal dielectric layer (201), a hexagonal metal patch (202) and a metal fine wire (203); The hexagonal metal patch (202) is arranged on the top surface of the regular hexagonal dielectric layer (201); Six metal thin wires (203) are led out from the hexagonal metal patch (202) and radiate to the edge of the regular hexagonal dielectric layer (201); The midpoint of the side length of the hexagonal metal patch (202) is arranged corresponding to the vertex of the regular hexagonal dielectric layer (201), and the metal fine wire (203) connects the midpoint of the side length of the hexagonal metal patch (202) and the vertex of the regular hexagonal dielectric layer (201); Both topological units consist of two parts, the four parts are centrosymmetrical and form four microstrip line ports, namely: The first microstrip line port (11) is an input port of the topological insulator directional coupler; The second microstrip line port (12) is a through port of the topological insulator directional coupler; The third microstrip line port (13) is a coupling port of the topological insulator directional coupler; The fourth microstrip line port (14) is an isolation port of the topological insulator directional coupler.

2. A topological insulator waveguide suitable for a microstrip transmission line according to claim 1, characterized in that: One end of the microstrip transmission line structure (102) is directly connected to the metal thin wire (203) of the valley topological insulator unit.

3. A topological insulator waveguide suitable for a microstrip transmission line according to claim 1, characterized in that: The boundary between two topological units is a straight line or a broken line bent at any angle.

4. A topological insulator waveguide suitable for a microstrip transmission line according to claim 1, characterized in that: The topological insulator waveguide is manufactured by using a printed circuit board process, an additive manufacturing process or a laser etching process.

5. A topological insulator waveguide suitable for a microstrip transmission line according to claim 1, characterized in that: When each topological unit consists of multiple parts, the topological units of the multiple parts are centrally symmetrically arranged.

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