A Broadband and Compact Millimeter-Wave Imaging System based on Synthetic Aperture Radar

In this paper, the design, realization, and demonstration of a broadband millimeter-wave imaging system based on the synthetic aperture radar technique (SAR) are discussed. The proposed system, operating within the frequency range of 25.3-30.8 GHz, consists of a tapered slot antenna as the transmitter and two half-circle antennas as the receivers. The size of the antenna is 19.5 * 8 mm with a maximum gain of 8.5 dB. The transmitter and the receiver antennas are printed on the same board. This feature leads to a highly compact and flexible configuration, enabling the applicability of the proposed imaging system in the handheld devices. Furthermore, it significantly reduces the fabrication cost of the system. The proposed broadband imaging system, being capable of performing 3D real-time imaging with high resolutions, can be easily calibrated for each frequency within the desired range. By performing 3D imaging from metallic objects with different shapes, we experimentally demonstrate the high performance of the proposed system, which offers great potentialities for a broad range of applications such as security, medical diagnostic, concealed object detection, to name a few.