An ultra-wideband Vivaldi and linear hybrid taper antenna for use in a near-field real-time phased array radar system

A novel ultra-wideband (UWB) antenna element is developed for use in a near-field phased array radar system. This antenna uses a Vivaldi-style tapered slot implemented on a printed circuit board (PCB). It consists of feed, taper, and rolled-edge sections that produce a gradual transition for electromagnetic energy providing better than 2:1 VSWR over a 30:1 bandwidth from 800 MHz to 25 GHz. The radiation characteristics are optimized for high gain (10-15 dBi) from 2 to 4 GHz, exceeding the directivity of most Vivaldi tapered designs. This element is designed for operation in a near-field phased array radar imaging system that produces realtime radar imagery at the frame-rate of 10.8 Hz for use in through-wall or any other real-time imaging applications.