Implementation of high-coupling and broadband transformer in RFCMOS technology

Abstract

This paper proposes a structure for transformer with high-coupling, broadband, and small chip area characteristics using current silicon-based technology. The proposed device has tight coupling (kappa = 0.92), wide bandwidth (f(SR) = 30.8 GHz), and minimum chip area (OD = 140 mu m). Furthermore, the analytical formula for calculating mutual inductance is derived in this study; experimental results indicate that the analytical formula is feasible. The proposed transformer will be useful in designing high-performance RF integrated circuits for wireless applications.