225 GHz triple-push RTD oscillator with 0.5 mW dc-power consumption

This study reports on a sub-mW triple-push oscillator using resonant tunnelling diodes (RTDs) operating at a frequency of 225 GHz. The triple-push RTD oscillator is designed based on a stability test using even/odd-mode equivalent circuit models and fabricated by using an indium phosphide monolithic microwave integrated circuit process. The fabricated IC exhibits an extremely low dc-power consumption (PDC) of 0.5 mW with a dc-to-radio-frequency efficiency of 1%. These results are attributed to both device characteristics of the RTDs with a low bias voltage of 0.4 V and a low peak current density of 0.74 mA/μm2 and an efficient triple-push topology exploiting the strong odd symmetry of the RTD I–V curve with a wide negative differential conductance voltage span of 0.46 V.