A CMOS K-Band Quadrature Generator

This letter presents a K-band quadrature signal generator in a standard 0.13 mu m CMOS process. The quadrature generator operates from 18 to 21 GHz. A maximum output power of -3.7 dBm (per I or Q channel) is achieved, and the down converted signal suppression is >25 dB at the operating bandwidth. A measured sideband rejection ratio >30 dB is achieved from 19 to 21 GHz, with a peak of >40 dB at 19.5-20.5 GHz. The current consumption of the quadrature generator is 49-54 mA from a 2-2.5 V supply with an effective chip area of 0.51times 0.44 mm
²
. To the author's knowledge, this is the first demonstration of a K-band quadrature signal generator with high spectral purity and quadrature accuracy.