A fully-integrated linearized CMOS bidirectional distributed amplifier as UWB active circulator

The design of a fully-integrated linearized CMOS bidirectional distributed amplifier (DA) based active circulator with broadband distortion cancellation capability is presented. The S₂₁ differential power gain peaks at 7 dB and then rolls off to a unity gain bandwidth of 11.5 GHz. The simulated tunable isolation performance is better than -26 dB. The simulated linearized IIP3 show a 10 dB improvement. Simulation results show that the co-design of DA based active circulator with on-chip loop antenna has 6 dB S₂₁ power gain added improvement from DC up to 5.2 GHz compared to a matched stand alone on-chip loop antenna S₂₁ power performance. The linearized CMOS bidirectional DA based active circulator was fabricated using the 0.13 ¿m CMOS technology and has a total silicon chip area of 1.887×0.795 mm².