RF circuit design aspects of spiral inductors on silicon

Abstract

The design and optimization of spiral inductors on silicon substrates, the related layout issues in integrated circuits, and the effect of the inductor-Q on the performance of radiofrequency (RF) building blocks are discussed. Integrated spiral inductors with inductances of 0.5-100 nH and Q's up to 40 are shown to be feasible in very-large-scale-integration silicon technology. Circuit design aspects, such as a minimum inductor area, the cross talk between inductors, and the effect of a substrate contact on the inductor characteristics are addressed. Important RF building blocks, such as a bandpass filter, low-noise amplifier, and voltage-controlled oscillator are shown to benefit substantially from an improved inductor-Q.