Low-SAR ferrite handset antenna design

The purpose of this project was the study of electrically small material coated antennas. In particular the use of a hybrid dielectric–ferrite material was examined, compared to dielectric alone, and ways it can improve antenna performance. The benefits resulting from the inclusion of ferrite were examined using both analytical and experimental methods. Initially a spherical analytical mathematical model was developed, to examine antenna efficiency, bandwidth and Specific Absorption Rate (SAR) in terms of different mixtures of relative permittivity εr and permeability μr. The theoretical model was then validated through a numerical transmission line matrix (TLM) simulation tool, applied to spherical and rectangular resonator geometries. It was observed that a material with equal values of relative permittivity and permeability in combination with specific positioning of the antenna in relation to the head, can give rise to the definitive small-size, high-efficiency, high-bandwidth, low-SAR antenna. [Continues.]