An Ultra-Wideband Two-Port Cascode Self-Mixing Mixer in 130 nm SiGe for Use in Incoherent Radar

An active unbalanced two-port mixer in 130 nm SiGe BiCMOS technology is presented which features an ultra-wideband RF input and measured conversion gain of up to 6 dB from 68 to 86 GHz in the E-band with a low power consumption of 55 mW. The mixer is designed specifically for incoherent radar which allows stand-alone operation of radar receivers since synchronization to a transmitted signal is not required. This paper concentrates on the characterization of a two-port self-mixing mixer utilizing two-tone CW measurements in K- and E-band. The ultra-wideband RF bandwidth of the self-mixing mixer allows the use of large bandwidth FMCW chirps for a potentially high radar range resolution. The presented two-port cascode mixer employs a novel circuit topology that is comparable to additive mixers, dedicated to high conversion gain-bandwidth performance.