CN112928420B

CN112928420B - Metal concave-embedded terahertz medium guided wave structure

Info

Publication number: CN112928420B
Application number: CN202110268924.XA
Authority: CN
Inventors: 施金; 陈燕云; 张凌燕; 刘栩; 徐凯; 郁梅
Original assignee: Nantong University; Nantong Research Institute for Advanced Communication Technologies Co Ltd
Current assignee: Nantong University; Nantong Research Institute for Advanced Communication Technologies Co Ltd
Priority date: 2021-03-12
Filing date: 2021-03-12
Publication date: 2022-06-10
Anticipated expiration: 2041-03-12
Also published as: CN112928420A

Abstract

The invention discloses a metal concave embedded terahertz medium wave guide structure, which is characterized in that a small-size metal surface is concavely embedded in the edge of a low-dielectric-constant medium cylinder with a diameter of near wavelength, fluctuation of group delay of electromagnetic waves propagated in a medium is adjusted, and a low-dispersion terahertz medium wave guide system with small size, easiness in processing and feeding and simple structure is realized.

Description

Metal concave-embedded terahertz medium guided wave structure

Technical Field

The invention relates to the field of microwave and terahertz communication, in particular to a metal concave embedded low-dispersion terahertz medium guided wave system.

Background

Terahertz (sub THz) guided wave systems are receiving wide attention in the fields of radar, environmental monitoring, biomedicine, remote sensing, ultra-wideband communication and the like. In a communication system, the high dispersion guided wave system has great influence on the modulation and demodulation of the system, and the complexity and the cost of the system are improved, so that the low dispersion terahertz guided wave system is favorable for improving the performance of the terahertz system.

In the existing terahertz guided wave system, the dispersion of the metal circular waveguide is large, which is not favorable for the low dispersion use requirement of the terahertz frequency band. The parallel plate waveguide can obtain lower dispersion, but has the problems of large overall size, complex feeding, difficult bending and the like. The photonic crystal waveguide and the circular dielectric waveguide do not have a metal structure, and the dispersion is lower than that of a metal circular waveguide in the aspect of dispersion, but the photonic crystal has the problems of complex structure, large size, difficulty in processing and the like; the circular dielectric waveguide is not large in size and easy to process, but the dispersion characteristic of the circular dielectric waveguide needs to be further improved. Therefore, the terahertz dielectric waveguide system which is small in size, easy to process and low in dispersion is invented on the basis of the circular dielectric waveguide, and has important significance.

Disclosure of Invention

The purpose of the invention is as follows: aiming at the prior art, a metal concave embedded terahertz medium wave guide structure is provided, and the low dispersion characteristic is realized.

The technical scheme is as follows: a metal concave embedded terahertz medium wave guide structure comprises a medium cylinder with a low dielectric constant, the diameter of the medium cylinder is between 0.9 and 1.2 wavelengths, an air groove is formed in the surface of the medium cylinder along the axial direction, the depth and the width of the air groove are far smaller than the diameter of the medium cylinder, and a metal layer is arranged on the inner side wall of the air groove.

Further, the number of the air grooves is one.

Furthermore, the number of the air grooves is multiple, and the air grooves are evenly distributed along the peripheral side of the medium cylinder at intervals.

Further, the depth of the air groove is between 0.1 and 0.25 times the diameter of the medium cylinder, and the width of the air groove is between 0.05 and 0.1 times the diameter of the medium cylinder.

Has the advantages that: according to the invention, the edge of the low-dielectric-constant dielectric cylinder with a diameter close to the wavelength is concavely embedded into the small-size metal surface, so that the fluctuation of the time delay of the electromagnetic wave group propagated in the dielectric is adjusted, and the low-dispersion terahertz dielectric wave guide system with small size, easy processing, easy feeding and simple structure is realized.

Drawings

FIG. 1 is a radial cross-sectional view of the structure of example 1;

FIG. 2 is an axial sectional view of the structure of example 1;

FIG. 3 is a simulation diagram of group delay for the structure of embodiment 1;

FIG. 4 is a radial cross-sectional view of the structure of example 2;

fig. 5 is an axial sectional view of the structure of example 2.

Detailed Description

The invention is further explained below with reference to the drawings.

Example 1:

as shown in fig. 1 and fig. 2, the metal recessed terahertz medium wave guide structure includes a low-dielectric-constant dielectric cylinder 1, and the diameter of the dielectric cylinder 1 is between 0.9 and 1.2 wavelengths. An air groove 2 is axially arranged on the surface of the medium cylinder 1, the depth of the air groove 2 is between 0.1 and 0.25 times of the diameter of the medium cylinder, and the width of the air groove 2 is between 0.05 and 0.1 times of the diameter of the medium cylinder and is far smaller than the diameter of the medium cylinder. The inner side wall of the air groove 2 is provided with a metal layer 3. Among them, low dielectric constant, i.e., dielectric constant less than 3, such as polytetrafluoroethylene, polyethylene, etc. The invention can open a groove on the edge of the medium cylinder during processing, and spray metal on the inner side surface of the groove, thereby realizing the preparation of the air groove 2 and the metal layer 3.

The diameter of the metal concave embedded terahertz medium wave guide structure is close to one wavelength, the depth of the concave embedded metal is far less than the wavelength, and the working mode is not a standard HE any more₁₁Mode, but field distribution close to HE₁₁The pattern, which may be referred to as a quasi-HE₁₁Mode, TE passing through a metal circular waveguide₁₁The mode is excited, and a wider operating bandwidth can be obtained. The signal is transmitted along the axial direction in the transmission system, the longitudinal component of the electric field can be reduced by introducing the concave embedded metal, and the uniformly distributed electric field is gathered at the bottom of the metal and is distributed in bilateral symmetry, so that the group time delay in the frequency band is relatively flat, and the whole guided wave structure obtains the low dispersion working characteristic.

The diameter of the terahertz medium wave guide structure of the embodiment is 3mm, as shown in fig. 3, the working frequency band can cover 127.5-152.5 GHz, and the ratio of the maximum group delay fluctuation to the bandwidth in the whole working frequency band is 0.084 ps/GHz/m, which indicates that the dispersion of the wave guide system is low.

Example 2:

as shown in fig. 4 and 5, the difference from embodiment 1 is only in the structure that the number of the air slots 2 is plural and the air slots are uniformly distributed along the circumferential side of the medium cylinder 1. In this embodiment, the number of the air grooves 2 is four, and a metal layer is embedded in the inner wall of each air groove 2. The working mechanism of the terahertz medium wave guide device is the same as that of the single-metal concave-embedded terahertz medium wave guide mechanism in embodiment 1, and is still a quasi-HE₁₁The mode, but the difference is that the electric field is diagonally symmetrical along the cross section, and is substantially the same as example 1 in dispersion characteristics, but the tension is uniform when bent, and is not limited by bending in a specific direction.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The metal concave embedded terahertz medium wave guide structure is characterized by comprising a medium cylinder (1) with a low dielectric constant, wherein the diameter of the medium cylinder (1) is between 0.9 and 1.2 wavelengths, an air groove (2) is formed in the surface of the medium cylinder (1) along the axial direction, the depth of the air groove (2) is between 0.1 and 0.25 times of the diameter of the medium cylinder, the width of the air groove (2) is between 0.05 and 0.1 times of the diameter of the medium cylinder, and a metal layer (3) is arranged on the inner side wall of the air groove (2); the number of the air grooves (2) is one; the signal is transmitted along the axial direction, the longitudinal component of the electric field is reduced through the concave embedded metal, and the uniformly distributed electric field is gathered at the bottom of the metal and is distributed in a bilateral symmetry mode.