Partial element equivalent circuit models in the solution of the electric field integral equation

3-D electromagnetic methods are fundamental design tools for complex high-speed systems. Among the integral equation-based techniques, the Partial Element Equivalent Circuit (PEEC) method has received a special attention in interconnect modeling, where mixed electromagnetic/circuit problems need to be solved. Retardation effects and the resulting delays must be taken into account and included in the modeling, when signal waveform rise times decrease and the corresponding frequency content increases or the geometric dimensions become electrically long. In this case, the enforcement of the Kirchhoff laws to PEEC delayed models leads to a set of delayed differential equations in a neutral form. The aim of this contribution is to present an overview of the PEEC method with special focus on the analysis of electrically long structures that require taking delays into account