Single-Shot Frequency-Diverse Near-Field Imaging Using High-Scanning-Rate Leaky-Wave Antenna

A frequency-diverse imaging system is proposed based on high-scanning-rate leaky-wave antennas (LWAs) that can provide image reconstruction across narrow bandwidths. Analytical, simulation, and experimental results are provided to characterize and demonstrate the performance of the system. The core of the approach relies on a high-scanning-rate LWA, and in this work, we propose a prototype design that can scan 70° within 500 MHz (corresponding to a scanning rate of 140°/GHz from 10 to 10.5 GHz), providing more independent measurements for the system than conventional approaches. In addition, compressive sensing with a wavelet transform is utilized to reduce the required frequency measurements across the frequency band to only 21. It is demonstrated that the proposed system can reconstruct scatterer’s width and thickness within an error of 3 mm (about 1/10 wavelength at 10 GHz) using only 21 measurements across a 500-MHz bandwidth within 10–10.5 GHz. It is also able to estimate the distance between two objects when their edge-to-edge separation is greater than 5 mm.