Slow Wave Structures for Miniature Antennas

Abstract

Engineered materials, such as new composites, electromagnetic bandgap, and periodic structures have attracted considerable interest in recent years due to their remarkable and unique electromagnetic properties. Among this class of media are the magnetic photonic (MPC) and degenerate band edge (DBE) crystals. These periodic media have the concurrent characteristics of wave slow down and impedance matching at their dielectric interface. The first allows for miniaturization, and the latter is equivalent to radiation efficiency. Overall these properties are a consequence of the anisotropic nature of the periodic media, allowing for internal phase shifting that leads to ray collimation for best aperture utilization. To a degree, they emulate zero index materials, and thus (planar) layers of the material serve the same purpose as a reflector dish. This important property of the MPC and DBE structures will be discussed at the meeting. The main focus of this work is two-fold: 1. The realization (in terms of material availability and fabrication) of the proposed periodic media, and their theoretical and measured performance for antenna applications. Specifically, we will pursue feed arrangements, impedance matching and metallizations/printings for maximum aperture efficiency. 2. Introduction of a concept that allows for emulation of the anisotropic properties of MPC/DBE media using a novel coupled line printed approach. This concept allows for the realization of the wave slow-down and impedance matching within a printed microwave structure, leading to new design methodologies for microwave components, including couplers, filters and printed antenna devices.