Enhancement of broadband performance for on-chip spiral inductors with inner-patterned-ground

Abstract

A set of on-chip spiral inductors with novel inner-patterned-ground (IPG) is presented in this article to enhance the broadband performance. By grounding the simple center metal cross, the IPG structure, an additional inner ground path is formed, the input impedance of the spiral inductor is reduced at the higher frequency range. When compared with conventional inductors, the quality factor (Q) of the IPG inductors increases by 15-30% over the frequency range of 15-35 GHz. The IPG inductors can be modeled based on a simple lumped equivalent circuit. The extracted inductance and quality factors are verified by on-wafer measurement up to 50 GHz. © 2008 Wiley Periodicals, Inc.