I. Introduction
Recently, great attention has been paid to low-noise frequency synthesizers' architectures employing integrated capacitive switched tuning LC oscillators. The applications for these circuits range from wireless to high-speed serial data communications. The main reason for the use of switched tuning is to enhance the limited frequency tuning range achievable with a standard LC architecture [1] without resorting to big varactors. Phase lock loop (PLL)-based frequency synthesizers using this approach have been presented in [2] [3] [4].