CN108091967B

CN108091967B - Half-mode substrate integrated waveguide dynamic adjustable attenuator based on graphene

Info

Publication number: CN108091967B
Application number: CN201810058376.6A
Authority: CN
Inventors: 陆卫兵; 张安琪; 刘震国
Original assignee: Southeast University
Current assignee: Southeast University
Priority date: 2018-01-22
Filing date: 2018-01-22
Publication date: 2023-10-13
Anticipated expiration: 2038-01-22
Also published as: CN108091967A

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

Half-mode substrate integrated waveguide dynamic adjustable attenuator based on graphene

Technical Field

The application belongs to the technical field of attenuators, and particularly relates to a half-mode substrate integrated waveguide dynamic adjustable attenuator based on graphene.

Background

An attenuator is an important element for controlling the energy of signal transmission without causing signal distortion and enhancing impedance matching.

Graphene has received attention in recent years due to its outstanding mechanical, electrical and optical properties, and some elements based on graphene in the microwave range have also been proposed in recent years. Since the conductivity of graphene is dynamically adjustable in the microwave range, there have been recently some documents proposing graphene-based dynamically adjustable attenuators.

The graphene-based dynamically adjustable attenuators reported at present are all based on microstrip line structures, but all have larger return loss, so that the performance of circuit elements connected with the attenuators is reduced.

In order to reduce the return loss of the attenuator and facilitate the integration of the attenuator with a planar circuit, the attenuator formed by placing the graphene sandwich structure near or between conductors of a planar transmission line is a good choice.

The currently reported tunable attenuator based on substrate integrated waveguide uses PIN diode to provide adjustable resistance so as to change the attenuation of the attenuator.

Disclosure of Invention

The application aims to: in order to solve the problems in the prior art, the application provides a half-mode substrate integrated waveguide dynamic adjustable attenuator based on graphene, which has the advantages of dynamically adjustable attenuation, lower return loss and wider frequency band.

The technical scheme is as follows: in order to achieve the above purpose, the present application adopts the following technical scheme:

the dynamic adjustable attenuator comprises a graphene sandwich structure and a half-mode substrate integrated waveguide, wherein the graphene sandwich structure and the half-mode substrate integrated waveguide are arranged in a contact mode, and 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 each single-layer graphene is respectively connected with bias voltage.

Respectively printing metal layers on the front side and the back side of the dielectric plate to form the half-mode substrate integrated waveguide; the graphene sandwich structure is connected with the metal layer on the front side.

And a row of metal through holes are arranged at the upper part of the half-module substrate integrated waveguide.

And two ends of the half-mode substrate integrated waveguide are connected with the microstrip line through the microstrip linear gradual change line.

The microstrip line is 50Ω.

The principle of the application: the application provides a half-mode substrate integrated waveguide dynamic adjustable attenuator based on graphene, which consists of a half-mode substrate integrated waveguide and a graphene sandwich structure which is parallel to the surface of a medium and is placed on the half-mode substrate integrated waveguide medium. Because the graphene can cause power loss on the half-mode substrate integrated waveguide, the attenuation amount of the attenuator can be controlled by changing the conductivity of the graphene through an applied voltage.

The beneficial effects are that: compared with the prior art, the graphene-based half-mode substrate integrated waveguide dynamic adjustable attenuator 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 of graphene and the length of graphene; meanwhile, the attenuator is simple in manufacturing process and easy to popularize and apply.

Drawings

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

FIG. 2 is a front view of a graphene-based half-mode substrate integrated waveguide dynamic tunable attenuator;

FIG. 3 is a graph of graphene surface impedance as a function of bias voltage;

FIG. 4 shows an attenuator S according to an embodiment ₂₁ Parameters;

FIG. 5 is an attenuator S of one embodiment ₁₁ Parameters.

Detailed Description

The application will be further described with reference to the accompanying drawings and examples of embodiments.

The reference numerals are: the graphene sandwich structure comprises a graphene sandwich structure 1, a half-mode substrate integrated waveguide 2, single-layer graphene 3, diaphragm paper 4, a microstrip linear gradual change line 5, a microstrip line 6, a metal via 7, a metal layer 8 and a dielectric plate 9. The single-layer graphene 3 is attached to the PVC.

As shown in fig. 1-2, the half-mode substrate integrated waveguide dynamic adjustable attenuator based on graphene comprises a graphene sandwich structure 1 and a half-mode substrate integrated waveguide 2 which are arranged in a contact mode, wherein the graphene sandwich structure 1 is arranged on the surface of a dielectric plate 9 in parallel, and the graphene sandwich structure 1 is connected with the half-mode substrate integrated waveguide 2. A bias voltage is applied to each single-layer graphene 3 to adjust the conductivity of the graphene sandwich structure 1.

The half-mode substrate integrated waveguide 2 is manufactured by a PCB process, wherein metal layers 8 are respectively printed on the front side and the back side of a dielectric plate 9, and the front side is shown in figure 2. The graphene sandwich structure 1 is connected with the metal layer 8 on the front surface.

The graphene sandwich structure 1 consists of two single-layer graphenes 3 and diaphragm paper 4. To adjust graphene conductivity, the separator paper 4 is saturated with ionic liquid, and each single layer of graphene 3 is connected to a bias voltage. In order to apply bias voltage to the single-layer graphenes 3 on both sides of the diaphragm paper 4, each single-layer grapheme 3 is in contact with the half-mode substrate integrated waveguide 2 at intervals of PVC so as to avoid the single-layer graphenes 3 from directly contacting the half-mode substrate integrated waveguide 2.

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

A row of metal vias 7 are disposed in the upper portion of the half-die substrate integrated waveguide 2. 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. The microstrip line 6 is 50Ω.

Fig. 3 is a graph of the surface impedance of single-layer graphene 3 as a function of bias voltage. The curve is obtained by experimental measurements. From fig. 3, it can be seen that the higher the bias voltage applied to the graphene sandwich structure 1, the smaller the surface impedance of the single-layer graphene 3.

Fig. 4-5 are attenuator performance parameters for particular embodiments. The curve is obtained by electromagnetic simulation software CST.

FIG. 4 is an illustration of an attenuator S ₂₁ Variation of the i parameter with frequency. FIG. 5 is |S ₁₁ Variation of the i parameter with frequency.

As can be seen from fig. 4, when the graphene surface impedance is reduced from 3000 Ω/∈s to 520 Ω/∈s s, the attenuation amount of the attenuator can be increased from 3dB to 15dB in the 8GHz-19GHz frequency band.

As can be seen from fig. 5, the S of the attenuator ₁₁ The I parameter is always smaller than-15 dB in the frequency range of 8GHz-19GHz, which means that the return loss of the attenuator is always small and the circuit at the two ends of the attenuator is not affected.

In fig. 4 and 5, 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 as follows: the length is 55.0mm, and the width is 10mm; the parameters of the half-mode substrate integrated waveguide 2 are as follows: the length is 105.0mm, the width is 8.74mm, the diameter of each metal via hole of the half-module substrate integrated waveguide is 1.43mm, and the interval between the circle centers of adjacent metal columns is 2.2mm; the parameters of the microstrip line 6 are: the width is 2.5mm; the parameters of the microstrip linear gradual change line 5 are: the width is 4.3mm and the length is 1.62mm.

Claims

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.