Second-Harmonic Injection Linearization of Millimeter-Wave FET Resistive Mixers

This letter demonstrates the application of the second-harmonic injection linearization technique in a fieldeffect transistor (FET) resistive mixer operating at Ka-band. The single-ended mixer uses a 0.15-μm gallium arsenide (GaAs) pseudomorphic high electron-mobility transistor (pHEMT) at its core. Compared to the same mixer without the second-harmonic injection, the linearized mixer achieves an improvement of up to 8 dB in the third-order intermodulation (IM3) levels while leaving the fundamental output power and noise figure unaffected. To the best of authors' knowledge, this is the first demonstration of the technique with a mixer operating at millimeter-wave frequencies.