Evolution of gain enhancement techniques in dielectric resonator antenna: applications and challenges

Abstract

AbstractDielectric resonator antennas (DRA) are advantageous due to their small size, high radiation efficiency, ease of excitation, and minimal metallic losses. Enhancing the gain of DRA will make them suitable for a variety of applications such as wireless communication technology. High-gain antennas are required for wireless communication to overcome the difficulties of high path loss. The researchers have presented numerous techniques, including stacked DRA, DRA array, and higher-order mode excitation for enhancing the gain. This article provides a comprehensive summary of the state of art techniques and geometries including stacking, frequency-selective surfaces superstrate, electromagnetic band gap structures, hybrid techniques, arrays, etc., for increasing DRA gain. Techniques to improve other parameters like bandwidth and radiation efficiency along with gain are also discussed. The challenges in each technique and the possible applications are presented. Based on the studies, it is observed that the DRA array technique is suitable for obtaining gains up to 19 dBi for radar-based applications. For low-profile DRA requirements, hybrid DRAs prove prolific in enhancing gain up to 16 dBi.