A novel variable-gain amplifier based on an FGMOS transistor

Abstract

In radio-frequency receivers, variable-gain amplifiers (VGAs) are often used in order to compensate for the change of the signal level during the channel transmission and to relax the constraints on the succeeding analog-to-digital converter (ADC). In this paper, a novel VGA is introduced using a floating-gate MOS transistor (FGMOS). The voltage gain, the linearity, the valid region for proper operation, and the sensitivity are discussed and quantitative expressions are derived for them. The performance of this amplifier is verified by simulation adopting the 45 nm CMOS technology with Vdd = 1 V.