This article describes a 0.3-THz reflection-based harmonic enhanced push-push VCO in 130-nm SiGe BiCMOS technology. The novel application of transmission lines and grounding capacitors in the design improves output power and efficiency. A broadband π-matching network contributes to enhanced output power (POUT) and optimizes phase noise. The VCO operates from 287–304 GHz, delivers a peak P_OUT of 3.61 dBm (2.3 mW), with dc-to-RF efficiency of 2.93%, phase noise of -112 dBc/Hz and a high figure of merit. Performance is competitive with implementations in other Si and InP-based technologies. The VCO finds application in THz sources for high speed wireless communications systems.