The dielectric resonator antennas (DRAs) have several advantages like high efficiency, compact size and ease of integration which makes them more popular as an antenna. In this thesis, the aperture-coupled regular and irregular pentagon shaped dielectric resonator antennas (DRAs) are presented providing wideband and multiband performances. The regular and irregular pentagon shape DRAs show wideband impedance matching (S11 = - 10dB) bandwidth of 42% (from 2.55 GHz to 3.9GHz) and 45.8% (from 2.57 GHz to 4.1GHz), respectively. Further, the irregular pentagon shape DRA also shows triple bands: 2.42GHz-2.61GHz (Band1), 3.15GHz-4.05GHz (Band2) and 5GHz-5.65GHz (Band3) with a percentage matching bandwidths of 7.55%, 23.77% and 12.2%, respectively. These DRAs offer acceptable directional radiation patterns for both wideband and multiband performances. Prototype of the regular pentagon shape DRA has been fabricated and experimentally verified for both the matching bandwidth and radiation performance. The simulated and measured results are in very good agreement. These DRAs can find applications in wireless communications devices such as base stations. The 1x2 and 1x4 linear array configurations of the wideband pentagon DRA was also investigated. The 1x2 array was studied for determining the inter-element spacing and mutual coupling between the elements. Next, 1x4 linear array was investigated for the phased array applications showing beam scan in the range of ±60° while maintaining the wideband matching response. Finally, this study was extended to achieve a fixed broadside beam by implementing corporate feed network.