A D-Band Wideband Single-Ended Neutralized Upconversion Mixer With Controlled LO Feedthrough in 65-nm CMOS

A D-band wideband passive single-ended upconversion mixer with controlled LO feedthrough in 65-nm CMOS process is presented in this letter. The LO feedthrough was controlled by the varactor and the neutralizing transmission line between the LO and RF ports of the mixer. In measurement, the proposed passive single-ended mixer had a conversion gain of −13.0±1.5 dB with an ultrawide 3-dB bandwidth from 110 to 160 GHz. The LO feedthrough suppression was from −38.9 to −24.4 dB at 135 GHz by changing the varactor bias. The measured OP1dB was −12.5 dBm at center frequency. The chip occupies 0.35 mm2, including pads.