Coupled-Line Push-Push Colpitts Oscillator Operating at 0.45 THz with High-Efficiency DC-to-RF 1.01% Based on Transferred-Substrate InP-HBT MMIC Process

Abstract Indium phosphide (InP) heterojunction bipolar transistor (HBT)-based THz oscillators are highly attractive for electronic THz systems used in radar and spectroscopy applications due to their high conversion efficiency and compact size. In this work, we demonstrate a push-push Colpitts oscillator. This oscillator is realized in a 0.5-µm single emitter finger width transferred-substrate (TS) HBT technology. The circuit design is modeled and implemented in the Advanced Design System (ADS). The core circuit layout is presented, with the circuit occupying an area without RF and DC pads of 0.09 mm 2 . Performance evaluations are conducted through harmonic balance (HB) simulation. The measured performance at 0.45 THz includes a phase noise of − 119.54 dBc/Hz at 100-MHz offset, an output power of − 6 dBm, and a DC-to-RF efficiency of 1.01%. The comparison between the results of simulations and measurements exhibits a very high degree of agreement. The development of this high-performance oscillator represents a significant advance in the field of ultrafast communications, including future wireless networks, as well as in advanced imaging and sensing technologies.