Sub-THz Sensor Array With Embedded Signal Processing in 90 nm CMOS Technology

The architecture and the operation of a sub-THz sensor array are presented, which have been implemented in standard 90 nm CMOS technology. The integrated sensor array is arranged around of 12 silicon field effect plasma wave detectors with integrated planar antennas. The received signals are further processed by pre-amplifiers, analog to digital converters, and a time shared digital domain lock-in amplifier. The system automatically locks to external modulation and provides standard digital streaming output. Instead of building a uniform array, seven different antenna types with various polarization properties (horizontal and vertical linear; left and right handed circular polarization) and spectral responsivity have been integrated. The sensors altogether provide broadband response from 0.25 to 0.75 THz. The peak amplified responsivity of the sensors is 185 kV/W at 365 GHz and at the detectivity maximum, the noise equivalent power (NEP) is near to 40 pW/√Hz. Under nonzero drain current, the peak sensitivity rises above 1.2 MV/W with a moderate NEP ~ 200 pW/ Hz at 50 nA source-drain current. Application example is provided as a multi-wavelength transmission imaging case study.