CN108091967B - Graphene-based half-mode substrate integrated waveguide dynamically adjustable attenuator - Google Patents

Abstract

The application discloses a half-mode substrate integrated waveguide dynamic adjustable attenuator based on graphene, which belongs to the technical field of attenuators and comprises a graphene sandwich structure and a half-mode substrate integrated waveguide which are arranged in a contact manner, wherein the graphene sandwich structure is arranged on the surface of a dielectric plate in parallel; the graphene sandwich structure comprises two single-layer graphenes and diaphragm paper; the diaphragm paper is soaked in ionic liquid, and bias voltages are respectively connected to each single-layer graphene. The half-mode substrate integrated waveguide dynamic adjustable attenuator based on graphene has the advantages of dynamically adjustable attenuation, lower return loss and wider frequency band, and the attenuation and the dynamic regulation range of the attenuation of the attenuator can be adjusted by adjusting the conductivity and the length of graphene; meanwhile, the attenuator is simple in manufacturing process and easy to popularize and apply.

Description

Graphene-based half-mode substrate integrated waveguide dynamically adjustable attenuator

Technical field

The invention belongs to the technical field of attenuators, and specifically relates to a graphene-based half-mode substrate integrated waveguide dynamically adjustable attenuator.

Background technique

The attenuator is an important component that controls signal transmission energy without causing signal distortion and can enhance impedance matching.

In recent years, graphene has received widespread attention due to its outstanding mechanical, electronic and optical properties, and some components based on graphene in the microwave band have also been proposed in recent years. Since the conductivity of graphene is dynamically adjustable in the microwave band, some recent literature has proposed dynamically adjustable attenuators based on graphene.

The dynamically adjustable attenuators based on graphene that have been reported so far are all based on microstrip line structure, but these attenuators all have large return losses, so the performance of circuit components connected to this attenuator will be affected. has declined.

In order to reduce the return loss of the attenuator and make it easy to integrate with planar circuits, an attenuator composed of a graphene sandwich structure placed near or between the conductors of a planar transmission line is a better choice.

The currently reported adjustable attenuators based on substrate integrated waveguides use PIN diodes to provide adjustable resistance to change the attenuation of the attenuator.

Contents of the invention

Purpose of the invention: In order to solve the problems existing in the existing technology, the present invention provides a graphene-based half-mode substrate integrated waveguide dynamically adjustable attenuator, which has dynamically adjustable attenuation, lower return loss, and wider frequency band. .

Technical solution: In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solution:

The graphene-based half-mode substrate integrated waveguide dynamically adjustable attenuator includes a graphene sandwich structure and a half-mode substrate integrated waveguide arranged in contact, and the graphene sandwich structure is placed in parallel on the surface of the dielectric plate; the The graphene sandwich structure includes two single-layer graphene and separator paper; the separator paper is soaked in ionic liquid, and each single-layer graphene is connected to a bias voltage.

Metal layers are printed on the front and back sides of the dielectric plate to form the half-mode substrate integrated waveguide; the graphene sandwich structure is connected to the metal layer on the front side.

A row of metal vias is provided on the upper part of the half-mode substrate integrated waveguide.

The two ends of the half-mode substrate integrated waveguide are connected through a microstrip linear gradient line and a microstrip line.

The microstrip line is 50Ω.

Principle of the invention: This application proposes a graphene-based half-mode substrate integrated waveguide dynamically adjustable attenuator. This attenuator consists of a half-mode substrate integrated waveguide and a half-mode substrate integrated waveguide medium placed parallel to the medium surface. Graphene sandwich structure. Since graphene causes power loss on the half-mode substrate integrated waveguide, the attenuation of the attenuator can be controlled by changing the conductivity of graphene through an applied voltage.

Beneficial effects: Compared with the existing technology, the graphene-based half-mode substrate integrated waveguide dynamically adjustable attenuator of the present invention has dynamically adjustable attenuation, lower return loss, and a wider frequency band, and can By adjusting the conductivity of graphene and the length of graphene, the attenuation amount of the attenuator and the dynamic control range of the attenuation amount are adjusted; at the same time, the attenuator of the present application has a simple manufacturing process and is easy to promote and apply.

Description of the drawings

Figure 1 is a schematic cross-sectional structural diagram of a side view of a graphene-based half-mode substrate integrated waveguide dynamically adjustable attenuator;

Figure 2 is a front view of a graphene-based half-mode substrate integrated waveguide dynamically adjustable attenuator;

Figure 3 is a curve of graphene surface impedance changing with bias voltage;

Figure 4 is the attenuator S ₂₁ parameters of a specific embodiment;

Figure 5 is the attenuator S ₁₁ parameters of a specific embodiment.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific implementation examples.

The reference numbers are: graphene sandwich structure 1, half-mode substrate integrated waveguide 2, single-layer graphene 3, diaphragm paper 4, microstrip linear gradient line 5, microstrip line 6, metal via 7, metal layer 8 and Media board 9. Single layers of graphene 3 are all attached to PVC.

As shown in Figure 1-2, the graphene-based half-mode substrate integrated waveguide dynamically adjustable attenuator includes a contact-arranged graphene sandwich structure 1 and a half-mode substrate integrated waveguide 2. The graphene sandwich structure 1 is placed parallel to the medium On the surface of the plate 9, the graphene sandwich structure 1 is connected to the half-mode substrate integrated waveguide 2. A bias voltage is applied to each single layer of graphene 3 to adjust the conductivity of the graphene sandwich structure 1 .

The half-mode substrate integrated waveguide 2 is manufactured through the PCB process. The process is to print metal layers 8 on the front and back sides of a dielectric plate 9. The front side is shown in Figure 2. The graphene sandwich structure 1 is connected to the metal layer 8 on the front.

The graphene sandwich structure 1 consists of two single layers of graphene 3 and separator paper 4. To adjust the graphene conductivity, the separator paper 4 is soaked in ionic liquid, and each single layer of graphene 3 is connected to a bias voltage. In order to apply a bias voltage to the single-layer graphene 3 on both sides of the diaphragm paper 4, each single-layer graphene 3 is separated by PVC and contacted with the half-mode substrate integrated waveguide 2 to prevent the single-layer graphene 3 from directly contacting the half-mode substrate. Integrated waveguide2.

Figure 2 is a schematic front view of the attenuator, which has four parts: the graphene sandwich structure 1, the half-mode substrate integrated waveguide 2, the microstrip linear gradient line 5 and the microstrip line 6 from the half-mode substrate integrated waveguide 2 to the microstrip line 6.

A row of metal vias 7 is provided on the upper part of the half-mode substrate integrated waveguide 2 . The two ends of the half-mode substrate integrated waveguide 2 are connected through the microstrip linear gradient line 5 and the microstrip line 6 . Microstrip line 6 is 50Ω.

Figure 3 is a curve of the surface impedance of single-layer graphene 3 changing with bias voltage. The curves are obtained through experimental measurements. It can be seen from Figure 3 that the higher the bias voltage applied to the graphene sandwich structure 1, the smaller the surface impedance of the single layer graphene 3 is.

Figures 4-5 are attenuator performance parameters of specific embodiments. The curve is obtained through the electromagnetic simulation software CST.

Figure 4 shows the |S ₂₁ | parameters of the attenuator as a function of frequency. Figure 5 shows the variation of |S ₁₁ | parameters with frequency.

As can be seen from Figure 4, when the graphene surface impedance drops from 3000Ω/□ to 520Ω/□, the attenuation of the attenuator can increase from 3dB to 15dB in the 8GHz-19GHz frequency band.

As can be seen from Figure 5, the |S ₁₁ | parameter of the attenuator is always less than -15dB in the 8GHz-19GHz frequency band, which means that the return loss of the attenuator is always very small and will not affect the circuits at both ends of the attenuator.

In Figures 4 and 5, the parameters of the dielectric plate 9 are: the relative dielectric constant of the medium is 2.2 and the thickness is 1.575mm; the parameters of the graphene sandwich structure 1 are: the length is 55.0mm and the width is 10mm; the half-mold substrate is integrated The parameters of waveguide 2 are: the length is 105.0mm, the width is 8.74mm, the diameter of each metal via hole of the half-mode substrate integrated waveguide is 1.43mm, the interval between the centers of adjacent metal columns is 2.2mm; microstrip line The parameters of 6 are: width is 2.5mm; the parameters of microstrip linear gradient line 5 are: width is 4.3mm, length is 1.62mm.

Claims (3)

1. A half-mode substrate integrated waveguide dynamic adjustable attenuator based on graphene is characterized in that: the semiconductor device comprises a graphene sandwich structure (1) and a half-mode substrate integrated waveguide (2) which are arranged in a contact manner, wherein the graphene sandwich structure (1) is arranged on the surface of a dielectric plate (9) in parallel; the graphene sandwich structure (1) comprises two single-layer graphenes (3) and diaphragm paper (4); the diaphragm paper (4) is soaked in ionic liquid, and bias voltages are respectively connected to each single-layer graphene (3); metal layers (8) are respectively printed on the front side and the back side of the dielectric plate (9) to form the half-mode substrate integrated waveguide (2); the graphene sandwich structure (1) is connected with one side of the metal layer (8) on the front side; and a row of metal through holes (7) are arranged at the upper part of the half-module substrate integrated waveguide (2).

2. The graphene-based half-mode substrate integrated waveguide dynamic adjustable attenuator of claim 1, wherein the attenuator is characterized by: the two ends of the half-mode substrate integrated waveguide (2) are connected with the microstrip line (6) through the microstrip linear gradual change line (5).

3. The graphene-based half-mode substrate integrated waveguide dynamic adjustable attenuator as set forth in claim 2, wherein: the microstrip line (6) is 50Ω.