Design of W-band Sub-harmonic Balanced Mixer Using $0.1\mu \mathrm{m}$ GaAs pHEMT Process

This paper presents a W-band (90GHz-110GHz) sub-harmonic single balanced mixer using a commercial 1.1μm GaAs pHEMT process from WIN Semi. Corp. Marchand balun at the LO port and matched filter circuit at the RF port and IF port are used to achieve excellent local oscillator (LO) to radio frequency (RF) and LO to intermediate frequency (IF) isolation. The proposed mixer operates with LO drive power 10 dBm and the conversion loss reaches 10 dB with a RF bandwidth more than 10 GHz. The achieved LO-to-IF isolation is better than 80 dB and the LO-to-RF and RF-to-IF isolation are better than 47 dB and 20 dB, respectively.