This paper presents a G-band triple-push voltage controlled oscillator (VCO) operating around 177GHz. The VCO, implemented in a commercial 0.13-µm RFCMOS technology, adopts a triple-push topology that is composed of 3 symmetrically coupled identical Colpitts sub-oscillators. Oscillation frequency can be tuned from 175.9GHz to 178.4GHz with varactor tuning voltage swept from 0 to 1.2V. The calibrated output power ranged from -19.7dBm to -16.6dBm depending on the oscillation frequency. The measured phase noise of the VCO is -80.2dBc/Hz at 1MHz offset. The results clearly demonstrate the possibility of applying triple-push topology for VCOs operating beyond 100GHz, enabling various high frequency applications that require tunable frequency sources.