The effects of a ground shield on spiral inductors fabricated in a silicon bipolar technology

The frequency dependence of the model parameters of patterned ground shield (PGS) inductors in large part is explained as a consequence of modeling a distributed system with a lumped model. Using an n/sup +/-buried/n-well PGS, the peak Q is improved by /spl sim/25% with small changes of L and C/sub p/. Having a PGS does not significantly improve isolation between inductors.