Terahertz detector for imaging in 180-nm standard CMOS process

Abstract

A CMOS terahertz (THz) detector implemented in a 180-nm standard CMOS process is proposed, and room-temperature detection of 0.94-THz radiation is demonstrated. The detector consists of an integrated on-chip patch antenna and a source-feeding NMOS transistor as the rectifying element. To improve the power transfer efficiency between the patch antenna and NMOS transistor, a novel short-stub matching network is proposed. An open quarter-wavelength microstrip transmission line connecting gate is proposed to eliminate the influence of the bonding wire and pad on the antenna-transistor impedance matching. Illuminated by a 0.94-THz BWO source, the measured voltage responsivity ($R_{\rm v}$) and noise equivalent power (NEP) of the detector are 31 V/W and 1.1 nW/Hz$^{1/2}$, respectively.