Vivaldi Antennas: Wideband radar antennas simulation and reality

Multiple applications sharing a single multiple-aperture array is a driver for research into wideband antenna design. Vivaldi antennas are inherently wideband and are known to have good RF characteristics, are inexpensive and easy to manufacture, and have a flat profile enabling construction of compact arrays. This paper investigates a wideband antipodal Vivaldi antenna over a 20:1 frequency range, with a focus on the key parameters needed to achieve ultra-wideband performance. We discuss tradeoffs and interdependencies of different parameters including the antenna shape, the dielectric material and the substrate thickness. We compare simulated results of Vivaldi antennas (using CST Microwave Studio) with measurements of prototypes.