Novel Si integrated inductor and transformer structures for RF IC design

Planar and 3D Si passive inductive structures are presented, with respect to their application in RF ICs. The modeling of the structures is realized by the use of a custom CAD tool, SISP. It Is shown how, for the first time, fast answers to complex questions can be obtained before fabrication, such as: inductance boost of up to 600% in three-layer spiral inductors compared to planar ones, with no cost in quality factor; optimization of the insertion and return losses of integrated transformers under area reduction schemes; modeling of practical integrated baluns; effect of physical separation on the crosstalk between inductors. The accuracy of modeling results is established through measurements in an array of fabricated structures.