A Broadband Mixer Up to 110 GHz With I–Q Outputs

An ultra-broadband mixer with I-Q outputs is proposed and analyzed in this paper. The mixer is composed of a distributed amplifier, a traveling wave power splitter and two active mixers where the input capacitors are absorbed in the artificial transmission lines. The orthogonal LO inputs are fed to the mixers via an on-chip Lange coupler. With the aid of loss compensation techniques, the proposed mixer can operate up to 110 GHz. An average conversion gain of 5.5 dB/14.5 dB is achieved with 1 dBm LO input power without/with the pre-distributed amplifier, respectively. 0.13- μm SiGe process is used to fabricate the proposed design. Including the testing pads, the total chip areas both without and with the pre-distributed amplifier are (1.2 ×1) mm
²
and (2 ×1) mm
²
, respectively.