Sampling phase detector using a resonant tunneling high electron mobility transistor for microwave phase-locked oscillators

A novel sampling phase detector (SPD) using a resonant-tunneling high electron mobility transistor (RTHEMT), which features strong nonlinear characteristics, is proposed and demonstrated as a means of achieving a simple, low-power-consumption SPD. We confirmed promising performance for an RTHEMT as a simple pulse generator in an SPD with low power consumption, even for a low reference-signal input level. An 11-GHz phase-locked oscillator is constructed along with the present SPD, and successfully phase-locked signals are obtained with it. These results clearly show the potential of constructing high-performance analog RF circuits based on RTHEMTs.