Comparison of regular and floating bulk transistors in ultra-wideband CMOS T/R switches

This work presents the theoretical analysis, circuit realization and characterization of two types of CMOS T/R switches based on the conventional NMOS and floating bulk NMOS transistors. An improved biasing circuit for floating bulk has been proposed. Two DC to 30 GHz CMOS T/R switches have been fabricated and measured in a 130 nm CMOS process. The regular switch has an insertion loss of 3.6 dB and an isolation of 28 dB up to 30 GHz while the floating bulk switch has an insertion loss of 2.8 dB and an isolation of 19 dB up to 30 GHz. The chip sizes are only 0.01 mm². The obtained results compare the state-of-the-art realizations.