Design of FMCW-Based Nonlinear Radar System and Its Performance Test

In this study, we designed and fabricated an FMCW-based nonlinear radar system and presented test results for nonlinear targets. The operating band of the transmitter of the proposed system is 3~3.2 GHz, and the operating band of the receiver was 6~6.4 GHz, which corresponded to the second harmonic of the transmission band. The transmit/receiver array antenna gain was 19 dBi, whereas the maximum output of the power amplifier and the maximum gain of the low-noise amplifier were 37 dBm and 16.4 dB, respectively. The performance of the proposed system was verified in free space and concealed conditions, and the signal processing technique used to prevent false alarms is the cell-averaged constant false alarm rate (CA-CFAR). Target detection tests were performed with six nonlinear targets, and it was confirmed that the targets were successfully detected in all tested environments.