Equivalent Circuit Representation of Silicon Substrate Coupling of Passive and Active RF Components

Abstract

Substrate coupling of radio frequency (RF) components is represented by equivalent circuits unifying a resistive mesh network with lumped capacitors in connection with the backside of device models. Two-port S-parameter test structures are used to characterize the strength of substrate coupling of resistors, capacitors, inductors, and MOSFETs in a 65nm CMOS technology with different geometries and dimensions. The consistency is finely demonstrated between simulation with the equivalent circuits and measurements of the test structures, with the deviation of typically less than 3dB for passive and 6dB for active components, in the transmission properties for the frequency range of interest up to 8GHz.