Bandwidth Considerations in Miniaturized Rectangular Dielectric Resonator Antennas

Abstract

In this thesis, an issue of bandwidth is considered in a rectangular dielectric resonator antenna (RDRA). Two techniques (merging of modes and stacking) of bandwidth improvement are introduced with miniaturized resonator. Single narrowband in RDRA is also introduced and investigated. Dual narrowband is proposed in a L-shaped DRA. It is compact structure as compared to a conventional DRA structure. newline newlineTheoretical analysis of a rectangular DRA is discussed. Resonant modes in the RDRA are presented with and#64257;eld distribution. Dielectric waveguide model (DWM)-mixed magnetic model (MMW) is discussed to predict resonant frequency, impedance bandwidth, and radiation Q-factor of the RDRA for TEz mode. Variation of resonant frequency with length, height and depth are studied as a function of relative permittivity of material. Effect of aspect ratios (length/height and depth/height) on resonant frequency is discussed. Expression of impedance bandwidth and radiation Q-factor are discussed as a function of physical parameters of the RDRA. Predicated maximum and minimum impedance bandwidth are discussed for different values of the aspect ratios. newline newlineLiterature survey on dielectric resonator antenna is carried out for bandwidth improvement as well as single-and dual narrowband. For bandwidth improvement, survey of various methods such as merging of modes, stacking/embedding DRA elements, modiand#64257;ed shapes of the DRA, and hybrid DRAs is presented. In the merging of modes of DRA, simple rectangular and cylindrical DRA designs are described. In the stacking/embedding method, two disk DRAs, triangle DRAs and embedded ring-disks DRA designs are presented with their structure and reported performance. Modiand#64257;ed shaped of DRAs namely, notched RDRA, truncated tetrahedron DRA, semi trapezoid DRA, and#64258;ipped staired pyramid DRA, and L-shaped DRA are discussed for bandwidth improvement. Hybrid DRAs, the DRA is attached with other kind of antenna, are discussed for ultra wideband operation. Two different methods of a narrowband DRA designs are...