I. Introduction
Unprecedented growth in wireless communications prompted the need for smaller and faster transistors. This sparks tremendous research effort in the development of better radio-frequency (RF) IC technologies [1]–[3]. In this costcompetitive industry, its often beneficial to integrate as many subsystems on silicon as possible. If technology and economics continue to improve, soon it is possible to integrate the entire RF system on a single chip [system-on-chip (SoC)] [4].