Analysis of the Effects of Differential Integrated Antennas on Voltage Responsivity of Sub- terahertz CMOS Detectors

Abstract

Characteristics of an integrated antenna are analyzed in terms of the voltage responsivity of a CMOS plasmon detector operating at sub-terahertz frequencies. The voltage responsivity, which is the main factor determining the detector’s performance, shows the ratio between the output voltage level of the detector and the incident signal power. Nevertheless, the responsivity measurement results in previous studies cannot be easily accepted because the incident power on the detector with the integrated antenna cannot be accurately obtained using the measurement setup. In those studies, simulated characteristics of the differential integrated antenna in the detector were considered for responsivity calculations owing to the difficulty in measuring the performance of the antenna operating at sub-terahertz frequencies. The proposed analysis is based on the previous studies in which the simulation results using the BSIM4 model were identical to the measurement results of the detector without the antenna. The 0.2 THz detector fabricated using TSMC 0.25 μm mixed-signal CMOS technology consists of differential detector cores, pre-amplifiers, main amplifier, bias circuitry, and integrated patch antenna, and is simulated using Cadence Spectre 18. The analysis results show that the compensation of the gain and the return loss of the integrated antenna can represent the calculation of the voltage responsivity as 3.68 times its simulated value.