RCS Calibration with Cylinder for Terahertz Radar in the Low SNR

A new calibration method for radar cross section (RCS) measurement in the low signal-to-noise ratio (SNR) condition is described. The RCS measurement system is a solid-state terahertz radar system. The microwave source of the radar system is generated from a phasor network analyzer (PNA). Both the transmitting and receiving chains are driving with four frequency doublers. The carrier frequency of the system arrives 220 GHz after 16 times frequency multiplied. However, each of these doublers introduce a power attenuation into our system, which results in a low SNR. We therefore developed a new calibration technology for RCS measurement, which can improve the calibration performance compared to the conventional method with a sphere. We measured the RCS data of both smooth surface cylinder and rough surface cylinder. Consequently, we calibrated the terahertz system with the RCS data of the smooth one. Then, the calibrated data of the both cylinder are obtained. The calibrated data are compared with calculated results, which shows that this novel method is feasible.