A W-band direct-conversion I-Q mixer in 0.13μm SiGe BiCMOS technology

This paper presents a W-band zero intermediate frequency (Zero-IF) fundamental down conversion mixer in 0.13 pm SiGe BiCMOS technology. Single balanced Gilbert cell is utilized as a core of mixer. RF signal is fed through an on-chip Lange coupler to realize I-Q channels. Measured results show that the conversion gain is greater than 7.5 dB from 83.5 GHz to 86 GHz when LO is fixed at 85 GHz with power lever of −3 dBm; and if IF is fixed at 300 MHz, the conversion gain is above 9.5 dB from 83 GHz to 86 GHz with LO@-3 dBm pumped, the I-Q channels are with differential IF outputs to facilitate differential-input baseband applications. The RF return loss is better than 20 dB over 70-to-100 GHz, and LO port return loss is better than 10 dB from 80 GHz to 90 GHz. The LO to RF isolation is more than 35 dB from 70 GHz to 110 GHz. The mixer consumes 57 mW DC power with 0.8×0.8 mm2 chip size.