Analysis of the effects of coupling through substrate and the calculus of the Q factor

A comparison of Y-parameters and S-parameters methodologies for the calculus of the quality factor (Q) in integrated inductors, is analyzed in this paper. For this reason two inductors are compared, one with low (planar inductor) and another with high (cross inductor) electric field coupling effects, in order to determine its influence on the Q calculus. The experimental results shows that assumptions made in Y-parameters Q calculus methodology can overestimate it value. The analysis was done over a 0.35µm CMOS technology using S-parameter measurements up to 10 GHz.