Analytical calculation of the impedance of lossy power/ground planes

Abstract

Power and ground planes are required to have low impedance over a wide range of frequencies. Parallel ground and power planes in multilayer printed-circuit boards exhibit multiple resonances, which increase the impedance. Dissipative loading the radial transmission line structure of the planes reducing the peaks of the resonances. The dissipative loads can be realized by resistors distributed on the surface or edges of plain pairs and lossy dielectric material can be applied for distributed loading. Calculations based on the analytical method and measurements results are presented for comparing to the calculated and simulated impedances.