A 35-to-83 GHz Multiconductor-Lines Signal Combiner for High Linear and Wideband Mixer

This letter proposes a broadband and low-loss multiconductor-lines signal combiner in 90 nm CMOS. The signal combiner consists of one broadside-coupled balun, two broadband in-phase power dividers, one edge-coupled balun, and four impedance-transformation lines. By using thin-film microstrip lines to avoid the loss from silicon substrate, the signal combiner has a simulated insertion loss of 8.1 dB and port-to-port isolations better than 42 dB from 35 to 83 GHz. The signal combiner is then integrated into a source-pumped mixer, and a $-1\pm 1.5 \mathchar"702D {\rm dB}$ conversion gain and a 13 dBm average input IP3 at a 6.5 mW total dc power are achieved in measurements.