A 22 — 40 GHz Wideband Image Rejection Mixer in $0.18-\mu \mathrm{m}$ CMOS Process

A wideband image-rejection sub-harmonic in-phase/quadrature (IQ) mixer is designed and implemented on standard 0.18-μm CMOS technology. To maintain high image-rejection ratio over a wide bandwidth, a local oscillator (LO) broadband 45° power splitter combined with a doubly balanced sub-harmonic Gilbert-cell mixer has been selected. The image rejection ratio is better than -30 dB from 22 to 40 GHz. The measured conversion gain of the receiver lies within -25 to -8 dB.