A Low-Power 340-GHz Receiver in 40-nm CMOS for THz Imaging Applications

A low-power 340 GHz CMOS receiver composed of a single-balanced mixer, a Marchand balun for differential LO generation, and an IF amplifier for terahertz (THz) imaging applications is proposed in this paper. The load resistor and gate bias of the proposed mixer are optimized to have the highest conversion gain and lowest noise Figure (NF) by selecting the IF frequency higher than the flicker-noise corner while ensuring the IF bandwidth is wide enough to meet the imaging system requirement. Moreover, the required optimal LO power for the highest conversion gain can be as low as -7 dBm, which greatly eases the design of THz LO generation circuits. Realized in a 40-nm CMOS technology, the proposed receiver can give measured conversion gain and NF of 31.8 and 24.3 dB, respectively, at 320 GHz while only consuming 10 mW from a 0.9 V supply.