410-GHz CMOS imager using a 4<sup>th</sup> sub-harmonic mixer with effective NEP of 0.3 fW/Hz<sup>0.5</sup> at 1-kHz noise bandwidth

Abstract

A 410-GHz imager consisting of a 4 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> sub-harmonic mixer formed with an anti-parallel diode-connected NMOS transistor pair, and an on-chip antenna with 4.4-dB simulated gain is demonstrated in 65-nm CMOS. At −1.6-dBm power delivered to the LO input bond pad, the imager achieves 16.8-dB voltage conversion loss and 34.1-dB DSB noise figure. When the noise bandwidth is 1 kHz, sensitivity is −110 dBm, which is 30 dB better than the previously reported CMOS imagers operating near or above 300 GHz. The corresponding effective noise equivalent power is 0.3 fW/Hz <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sup> .