Negative-differential-conductance RTD amplifier MMIC with record foms of gain-to-dc power ratio and noise figure

An ultralow-dc-power negative-differential-conductance (NDC) microwave amplifier using resonant tunneling diodes (RTDs) is presented and its noise figure characteristic is for the first time reported. The fabricated amplifier exhibits an extremely low dc-power consumption of 155 μW along with good RF performances of an RF gain of 8.1 dB, a return loss of more than 11 dB, and a noise figure of 4.5 dB at 5.5 GHz. The gain-to-dc power ratio was estimated to be 52.2 dB/mW. The figures-of-merit (FOMs) of the achieved gain-to-dc power ratio and noise figure are record for sub-mW low-power monolithic amplifiers at the related frequency band.