A balanced frequency doubler has been demonstrated in 0.25-μm SOI SiGe BiCMOS technology operating from 22GHz to 29GHz with high fundamental frequency suppression and high conversion gain. A LC resonator circuit is designed to improve the suppression and conversion gain. The measured fundamental frequency suppression of greater than 45dBc is achieved at an input power of 9dBm in the 2229GHz. Moreover, measured maximum conversion gain of 12.6dB is obtained at an input power of 19dBm. The frequency doubler works on 3.3V and doubler core only consumes 7.9mW DC power.