MMIC resonant tunneling diode oscillators for THz applications

This paper presents a monolithic microwave integrated circuit (MMIC) that combines two InGaAs/AlAs resonant tunneling diodes (RTDs) in parallel. By employing appropriate circuitry the oscillators generate an output power of about 1 mW (−0.1 dBm) at 39.6 GHz and (−0.2 dBm) at 75.2 GHz which are the highest power reported for RTD-based oscillators in the relative frequency range. This work demonstrates that circuit-based power combining technique can be used to solve the bottle-neck of RTD oscillators, i.e. low output power at millimeter-wave or even higher frequencies. The techniques show the potential to be implemented at terahertz (THz) frequencies.