1.5-V 1.8-GHz SOI low noise amplifiers for PCS receivers

Abstract

CMOS is competing with bipolar and GaAs in the radio-frequency integrated circuits (RFIC) arena for wireless communications. SOI technology earns more credit for the Si-based CMOS family due to its improved RF performance. SOI promises better device characteristics than bulk technology and reduces substrate noise coupling. In addition, the buried oxide improves the quality (Q) factor of the on-chip planar inductors. So far, only the results of single-transistor low-noise amplifiers (LNA) based on SOI/SOS technology have been reported (Johnson et al., 1998; Harada et al., 1998). This paper reports the first SOI LNA with a cascode topology which offers performance advantages over other circuit configurations. The LNA circuit, operating at 1.8 GHz, can be used as a front-end amplifier for personal communications services (PCS) systems, which are allocated within the 1.7 GHz and 1.9 GHz band.