A fully-integrated 860-GHz CMOS terahertz sensor

This paper proposes a fully-integrated 860-GHz terahertz wave sensor. The sensor integrates a terahertz detector and readout circuit in 180-nm standard CMOS process. The readout circuit consists of a low-noise instrumentation amplifier and a high-resolution AZ-ADC. Transmissive imaging without source modulation (no lock-in technique required) is realized using the sensor. The detector consists of a novel on-chip grounded patch antenna, a source-feeding NMOS field effect transistor and matching networks. A quarter-wavelength microstrip transmission line is designed to connect the gate of the NMOS transistor to eliminate the influence of bonding wire and pad. The measured maximum voltage responsivity (Rv) and minimum noise equivalent power (NEP) of the detector at 860 GHz are 3.3 kV/W and 106 pW/Hz1/2, respectively. The measured readout circuit noise is 2. 03 μVrms.