Antenna Gain Enhancement Using a Photonic Band Gap Reflector

摘要

Scientists have long known that periodic structures can filter electromagnetic (EM) waves. In the last decade, extension of one- and two- dimensionally periodic structures into a third periodic dimension has produced photonic band gap (PBG) structures. A PBG structure is characterized by its omnidirectional stop band at a set of frequencies determined by the structure's periodicity and permittivity. In the present research, we investigate such a structure as an antenna reflector. We aim to develop a modeling approach that provides accurate computations of PBG behavior without relying on massively parallel processing. We also construct and measure the bulk reflection and transmission properties of a PBG structure, then use it as a planar reflector for a two-arm spiral antenna. We measure the same antenna's radiation properties when mounted above an absorber loaded cavity and a conducting ground plane to determine whether the PBG reflector provides gain enhancement. This comparison of a PBG reflector's performance against standard mounts for a practically useful broadband antenna is unique in PBG research.