A 293/440 GHz Push-Push Double Feedback Oscillators with 5.0/−3.9 dBm Output Power and 2.9/0.6 % DC-to-RF Efficiency in 65 nm CMOS

This work proposes a push-push double feedback oscillator (DFBO) topology, which is able to reduce the parasitic capacitance of the transistor, and satisfy the condition for maximum power at fundamental (fo) and 2nd harmonic (2fo) frequencies simultaneously, thus maximizing the oscillator output power. Oscillators adopting the proposed topology are implemented in a 65-nm CMOS, and the measurements show the maximum output powers of 5.0 and −3.9 dBm with maximum DC-to-RF efficiencies of 2.94 and 0.58 % at operating frequencies of 293 and 440 GHz, respectively.