A Review of Tuning Techniques of On-Chip Terahertz VCO

This paper presents a comprehensive review of tuning techniques of on-chip Terahertz VCO. Case studies are introduced for the tuning techniques of bias tuning, varactor tuning with enhanced negative resistance, inductive tuning and indirect varactor tuning. Indirect varactor tuning can achieve wide tuning range of 8% while keep good phase noise of -80.3dBc/Hz at 1MHz offset for a 300GHz VCO. It is a good candidate for the application of wideband on-chip Terahertz VCOs.