Method of Moments Analysis of Arbitrary Structures in Shielded Layered Media

Abstract

Method of moments analysis of planar multilayer circuits typically assumes that conductors are infinitely thin and only surface currents need be modeled. Modern fabrication techniques, especially for high-frequency integrated circuits, can easily create structures that require modeling volume current. We present here a complete volume current-based method of moments analysis of arbitrary structures embedded in shielded multilayer media. The volume rooftop, uniform via, and tapered via basis functions that we present are key for such an analysis. The embedding layered media is not meshed as it is automatically included in the Green's function. The required integrations (in six dimensions) of the Green's function have been evaluated analytically with full results presented as a two-dimensional infinite summation that is rapidly evaluated to full precision using the FFT algorithm. Planar circuits using thick metal are typically analyzed to high accuracy one to three orders of magnitude faster due to reduced subsection count.