Composite Delay-Informed Rational Kernel for Modeling of Electrically Long Interconnects

Abstract

This work presents a novel composite Gaussian process (GP) model for representing the complex-valued scattering parameters (S-parameters) of electrically long microwave interconnects as a function of frequency. The proposed model integrates a rational Szegö kernel, which captures the holomorphic structure and Hermitian symmetry of S-parameters, with a delay-informed periodic kernel designed to capture oscillatory behavior induced by wave propagation, thus resulting in improved predictive accuracy.