An I/Q mixer with an integrated differential quadrature all-pass filter for on-chip quadrature LO signal generation

A down-conversion in-phase/quadrature （l/Q） mixer employing a folded-type topology, integrated with a passive differential quadrature all-pass filter （D-QAF）, in order to realize the final down-conversion stage of a 60 GHz receiver architecture is presented in this work. Instead of employing conventional quadrature generation techniques such as a polyphase filter or a frequency divider tbr the local oscillator （LO） of the mixer, a passive D-QAF structure is employed. Fabricated in a 65 nm CMOS process, the mixer exhibits a voltage gain of 7-8 dB in an intermediate frequency （IF） band ranging from 10 MHz-1.75 GHz. A fixed LO frequency of 12 GHz is used to down-convert a radio frequency （RF） band of 10.25-13.75 GHz. The mixer displays a third order input referred intercept point （IIP3） ranging from -8.75 to -7.37 dBm for a fixed IF frequency of 10 MHz and a minimum single-sideband noise figure （SSB-NF） of 11.3 dB. The mixer draws a current of 6 mA from a 1.2 V supply voltage dissipating a power of 7.2 mW.