Low‐power amplitude modulator for wireless application using underlap double‐gate metal–oxide–semiconductor field‐effect transistor

Abstract

In this study, a design guideline for a modified low-power wideband on-chip amplitude modulator (AM) based on independently driven double-gate metal–oxide–semiconductor field-effect transistor (IDDGMOS) is proposed. The AM performance is then analysed for three different types of underlap engineered IDDGMOS devices. It is observed that the modulator designed with IDDGMOS presents a higher gain and bandwidth for lower power input signals. For analysing the gain–bandwidth performance of the modulator circuit, a small signal model for the devices is considered. The linearity and noise performance of the modulator circuit for different IDDGMOS structures is analysed by studying the 1 dB compression point and the signal-to-noise ratio. The analysis suggested that the most efficient AM circuit performance is achieved for the symmetric underlap IDDGMOS device. The symmetric underlap IDDGMOS AM circuit yields a gain of 11 dB, a bandwidth of 5.5 GHz and a 47.2% efficiency with a distortion less input signal power range of −60 to −33.5 dB. Moreover, the reduced power loss is about 0.047% of the power loss obtained for the conventional complementary metal–oxide–semiconductor device, whereas the bandwidth of the circuit almost triplicates.