Comparison of the effectiveness of cross-coupling reduction methods in PCB transmission lines

Abstract: The paper presents the results of evaluation of the efficiency of methods for reduction of cross-couplings in transmission lines. For this purpose, using the example of a pair of coupled lines, the coupling coefficients (capacitive, inductive and electromag-netic) and the cross-talk level in a passive conductor are esti-mated with an increase in the distance between them, applica-tion of a dielectric coating and imposing of a grounded conduc-tor between the line signal conductors. It is established that for long-distance transmission lines, application of a dielectric coat-ing is the efficient method, but if the length of the line is short, efficiency shifts towards imposing of a grounded conductor into the line. Additionally, the calculated frequency dependences of the S-parameters of the line confirmed this conclusion.

Keywords: grounded conductor, protective varnish, pair of cou-pled lines, cross-talk, coupling coefficients, signal integrity