Особенности исследования характеристик ленточных высокочастотных проводов, использующих трехпроводную схему передачи сигналов

Abstract

The characteristics of tape conductors using the three-wire signal transmission arrangement are considered. The theoretical and experimental studies of tape conductor circuits are based on an analysis of multiwire planar communication lines. At the first stage of studies the cable article circuits modeling method is used. An example of the electromagnetic field model in the three-wire line of a tape conductor with insulation of limited thickness is given. It is pointed out that the electromagnetic field is concentrated not only in the tape conductor’s plane, but partly spreads into the surrounding space. The modeling is based on the analogy existing between the electrostatic field in the conductor insulation and the stationary electric field of the model. Its complexity is main difficulty in implementing the method. An electric field model developed using the oblique squares method is presented, the use of which makes it possible to determine the tape conductor capacitance and the extent to which the conductor circuits are immune to mutual influence. The electrodes in the model are arranged taking into account the relative permittivity of individual insulation layers. For theoretical calculations both the elegiac magnetic field structure in the insulation and the electric field structure in the three-wire line conductors have been studied. The current density profiles in the conductor cross sections determined taking the skin effect into account are presented. Formulas for calculating the attenuation ratio for the single three-wire circuit of a high-frequency tape conductor are given along with formulas for calculating the electrical resistance taking into account the skin effect and the proximity effect for round and rectangular cores of tape conductors, and for calculating electrical capacitance at certain ratio of tape conductor thicknesses. The frequency dependence of an attenuation ratio for a three-wire cable circuit is given. The obtained study results show that, all other factors being identical, tape conductors with rectangular-shaped cores have a lower attenuation ratio. This is attributed to the influence of the skin effect and proximity effect on losses in the cores, which is also confirmed from an analysis of the tape conductor circuit electromagnetic field patterns obtained by simulation.