A Through-Dielectric Ultrawideband (UWB) Switched-Antenna-Array Radar Imaging System

A through-dielectric switched-antenna-array radar imaging system is shown that produces near real-time imagery of targets on the opposite side of a lossy dielectric slab. This system operates at S-band, provides a frame rate of 0.5 Hz, and operates at a stand-off range of 6 m or greater. The antenna array synthesizes 44 effective phase centers in a linear array providing $\lambda /2$ element-to-element spacing by time division multiplexing the radar\´s transmit and receive ports between 8 receive elements and 13 transmit elements, producing 2D (range vs. cross-range) imagery of what is behind a slab. Laboratory measurements agree with simulations, the air-slab interface is range gated out of the image, and target scenes consisting of cylinders and soda cans are imaged through the slab. A 2D model of a slab, a cylinder, and phase centers shows that blurring due to the slab and bistatic phase centers on the array is negligible when the radar sensor is located at stand-off ranges of 6 m or greater.