Modeling of an Uncooled CMOS THz Thermal Detector With Frequency-Selective Dipole Antenna and PTAT Temperature Sensor

Abstract

A thermal THz detector based on commercial CMOS technology working in room temperature is proposed. The THz electromagnetic wave is first selectively absorbed by an on-chip λ/4 dipole antenna realized in the metallization layer. The absorbed wave energy is then converted to Joule heat energy via a polysilicon resistor. The heat-generated temperature rise is finally detected by a proportional to absolute temperature sensor. The theoretical analysis and physical modeling of the detector including the mechanism of the electromagnetic energy absorption, the thermal conversion, and the electrical circuit response, are presented. The detectors at three typical THz frequencies of 1, 2.9, and 28.3 THz are designed in standard 0.18-μm CMOS technology and post-simulated to illustrate the detector's frequency-selective capability in the whole THz range. The simulated detector's voltage responsivity is 18.0 V/W at 1 THz, 18.9 V/W at 2.9 THz, and 18.6 V/W at 28.3 THz, respectively. The noise equivalent power is 1.7 μW/√Hz at the three frequencies.