RU26688U1 - RIBE-DIELECTRIC WAVEGUIDE - Google Patents

Abstract

An edge-dielectric waveguide comprising a metal conductor located on a dielectric plate and a substrate, characterized in that, in order to reduce ohmic losses in the working frequency band, the metal conductor is made in the form of a wedge with an angle α at an apex lying on one face on the plate, and the substrate is made of a dielectric with a permeability ε <ε, where ε is the dielectric constant of the plate and the angle α> 0.

Description

Dielectric waveguide

The invention relates to transmission lines of microwave, microwave, ultrahigh-frequency (EHF) ranges and is intended for use in integrated circuits of these ranges up to optical frequencies. The aim of the invention is to expand the operating range in the region of EHF and optical frequencies, as well as reducing ohmic losses.

Known microstrip waveguide (see AS USSR No. 1626282 A1, N 01 RZ / 16, publ. 1991), containing a metal strip conductor located on a dielectric plate, and a substrate that is made of a dielectric with a relative dielectric constant f 2 where e is the dielectric constant of the plate,

and the plate thickness d satisfies the inequality, U (ei-fj) 2, where I am the wavelength in free space (see Fig. 1).

A disadvantage of the known device is the increased loss near the edges of the strip conductor, as well as the impossibility of placing it near the edge of the microcircuit due to the influence of this edge on the parameters of the waveguide, which determine its waveguide properties.

Closest to the proposed technical solution is a strip waveguide with a boundary wave (see article by S. V. Zaitsev Edge waves in strip structures. Izv. VUZ Radiofizika, No. 3.1987), containing a dielectric plate of thickness d with a permeability e ,, surrounded by a medium with permeability e, and a very wide strip conductor located on it, in the vicinity of the edge of which an edge wave propagates (see figure 2).

The disadvantage of the prototype device is the relatively high ohmic losses due to the strong feature of the electromagnetic field on the edge of the conductive strip conductor.

The technical effect to which the proposed transmission line is directed is to reduce ohmic losses in it and simplify its structural implementation.

This effect is achieved by the fact that in an edge-dielectric waveguide containing a dielectric plate, a dielectric substrate and a metal conductor, the latter is made in the form of a wedge with an angle a at the apex and is located on one face on the plate, the substrate being made of a dielectric with permeability s b, where e is the dielectric constant of the plate, and the angle a is greater than zero.

A cross-section of the proposed waveguide is shown in FIG. 3 (as mentioned above, in FIG. 1 and FIG. 2, configurations of known transmission lines — analog and prototype, respectively) are shown. The inventive edge-dielectric waveguide contains

a dielectric plate 1, a dielectric substrate 2, and a metal conductor 3 in the form of a wedge with an angle a at the apex, lying on one face on the dielectric plate.

An edge-dielectric waveguide holds a surface wave that propagates in a direction perpendicular to the plane of the pattern. The formation of such a wave occurs for two reasons. Firstly, at the interface between the two dielectric media of the plate and the substrate, there is a phenomenon of total internal reflection (provided that the dielectric constant of the plate is greater than the dielectric constant of the substrate) and, as a result, the electromagnetic field tends to concentrate in the plate. Secondly, a metal wedge creates a feature of the electromagnetic field near the edge, which leads to an increased concentration of field energy in its vicinity, and given that this edge is located on the boundary with the surface of the dielectric plate, this provides an additional deceleration of the surface wave (also called the edge wave) , and, therefore, its retention in the edge of the edge. By choosing the angle a at the apex of the wedge and choosing the thickness of the plate d, it is possible to control the concentration of electromagnetic energy transferred by the considered boundary wave through the cross section of the waveguide, and hence the amount of linear ohmic losses in it.

Advancing the working frequency range of the proposed waveguide to the optical frequency region is achieved by reducing the dielectric constant g, and e while maintaining the inequality.

Description of the experimental results.

An experiment was set up to verify the existence of a boundary wave and measure its wavelength. The resonator formed by two plane-parallel metal plates and the investigated section of the waveguide between them, consisting of a 1 mm thick polycore dielectric plate and a metal wedge with an angle of 90% was excited by a segment of a 50-ohm microstrip line deposited on the back of the dielectric plate open at the end.

Measurements carried out on a panoramic SWR and attenuation meter showed a sharp drop in SWR (to a value of 1.25) at two frequency points: 8.6 GHz and 11.47 GHz. At these points, the edge wavelength D was calculated and compared with the formula

resonance:

L, where L is the cavity length, which in our case is 28 mm, n is a positive integer corresponding to the resonance number. For

the first frequency point was D 28.2 mm, for the second - 27.7 mm.

This means that the second and third resonances were observed. The first half-wave resonance, which was supposed to take place at a frequency of ~ 5 GHz, was not detected, which is explained by the very weak concentration of the field of the edge wave at this frequency in the vicinity of the edge.

The proposed waveguide can be used as a broadband transmission line of microwave and EHF ranges, and also serve as the basis for the development of new functional devices of these ranges.

/ B.M. Temnov / /R.V. Budaragin / / A. A. Titarenko /

Claims (1)

An edge-dielectric waveguide comprising a metal conductor located on a dielectric plate and a substrate, characterized in that, in order to reduce ohmic losses in the working frequency band, the metal conductor is made in the form of a wedge with an angle α at an apex lying on one face on the plate, and the substrate is made of a dielectric with a permeability ε ₂ <ε ₁ , where ε ₁ is the dielectric constant of the plate, and the angle α> 0.