Sensor and Simulation Notes Note 498 April 2005 A Solid Dielectric Lens Impulse Radiating Antenna with High Dielectric Constant Surrounded by a Cylindrical Shroud

We continue here our investigation of Solid Dielectric Lens Impulse Radiating Antennas (SDL IRAs), which are intended for Ultra-Wideband, high-voltage radiation from the front end of an electrically conducting cylindrical shroud. This device is intended to radiate the highest possible field from the smallest possible aperture using the highest possible source voltage. Furthermore, this antenna is intended to be capable of sustaining high g-forces. The antenna consists of a TEM horn embedded into a solid dielectric, with a lens in the aperture at the airdielectric interface. The antenna is surrounded by an electrically conducting cylindrical shroud that is open at the ends. We extend our earlier work by replacing the polyethylene dielectric material with Kynar® PVDF (PolyVinyliDene Fluoride), which has a dielectric constant of 8.5. Our goal is to improve the low-frequency response of the antenna by making it appear electrically larger. Our investigation includes both numerical modeling of the antenna and experimental measurements. We found the higher dielectric material improved the performance only at very low frequencies, where our measurement technique is approximate. At other frequencies, the performance was either the same or worse than that of an earlier version.