Miniature UWB Conformal Aperture with Volumetric Inductive Loading

This paper introduces a new concept for a conformal aperture antenna that operates from 3000 MHz down to VHF frequencies. The intended size is less than 15 in. diameter, corresponding to lambda/22 at 30 MHz, and having a gain better than -15 dBi at the lowest operational frequency with a nominal gain of greater than 0 dB at the higher frequencies. A key aspect of this paper is the use of inductive loading within the entire substrate/superstrate volume rather than modifying the metallization only on the surface of the substrate. The proposed antenna is based on a spiral configuration which has been miniaturized using a combination of dielectric and inductive loading. A significant effort is also made to maintain a thin cavity-backed configuration. This is done by using a ferro-metallic ground plane that is optimally designed and integrated with the dielectric substrate along with volumetric coiling for best performance. Overall, it is shown that a 6 in. aperture can operate down to 130 MHz (lambda/15 aperture) using a combination of dielectric and volumetric inductive loading