Dynamic Soultions for Single and Coupled Microstrip Lines

摘要

The investigation presents theoretical and experimental results of single and coupled microstrip propagation on both a pure dielectric and a ferrite substrate. The theory enables one to obtain the frequency dependence of phase velocity and characteristic impedance and also to obtain the electromagnetic field quantitites around the microstrip line. It utilizes a Fourier transform method in which the hybrid mode solutions for a 'fictitious' surface current at the substrate-air interface are summed in such a way as to represent the fields caused by a current distribution that is finite only over the region occupied by the conducting strip and is assumed equal to that for the static case. The theory for the magnetized ferrite microstrip takes into account both the diagonal and off-diagonal components of the substrate's permeability tensor. Excellent agreement is obtained between experimental and theoretical results for single microstrip lines on both ceramic and demagnetized ferrite substrates. The coupled microstrip theory is applied to two commonly used microwave integrated circuit devices, the directional coupler and the meander- line phase shifter. (Author)