Four Element Multilayer Cylindrical Dielectric Resonator Antenna Excited by a Coaxial Probe for Wideband Applications. Raghvendra Kumar Chaudhary 1 , Kumar Vaibhav Srivastava 2 , Animesh Biswas 3 Department of Electrical Engineering Indian Institute of Technology Kanpur, INDIA. 1 raghav@iitk.ac.in, 2 kvs@iitk.ac.in, 3 abiswas@iitk.ac.in Abstract— The main objective of the present study is to improve the bandwidth of the dielectric resonator antenna (DRA). A new four-element multilayer cylindrical dielectric resonator antenna (MCDRA) array above the ground plane is proposed here. MCDRA is easy to design and excited with HE 11δ mode excited in each MCDRA by centrally placed dielectric resonator in which TM 01δ mode excited. The effect of design parameters such as permittivity of materials, probe height and arrangement of dielectric layers are investigated and the excited modes (i.e. TM 01δ and HE 11δ ) are also been confirmed by simulations. The simulation is performed on Ansoft’s HFSS package. The proposed multilayer cylindrical dielectric resonator antenna (MCDRA) can offer an impedance bandwidth of ~47% for the return loss below ─10dB where frequency range is from 4.06 to 6.07 GHz and resonance frequency is 4.3 GHz with monopole like radiation pattern and it is stable in the passband with 4.73 dB gain. Keywords- Dielectric resonator (DR), dielectric resonator antenna (DRA), multilayer cylindrical dielectric resonator antenna (MCDRA), monopole-type antenna, probe coupling. I. INTRODUCTION The dielectric resonator (DR) was used as an energy storage device rather than a radiator in microwave circuits for many years [1] but open dielectric resonators (DRs) offer attractive features as antenna elements. These include their small size, mechanical simplicity, high radiation efficiency due to no inherent conductor loss, relatively large bandwidth, and simple coupling schemes to nearly all commonly used transmission lines, and the advantage of obtaining different radiation characteristics using different modes of the resonator [2]. The experimental investigation of the resonant cylindrical dielectric cavity antenna capable of providing efficient radiation done by Long et al. [3]. The radiation Q factor of a DR antenna depends on its excitation modes as well as the dielectric constant of the ceramic material. The Q-factor increases and hence the bandwidth decreases with increasing dielectric constant and vice-versa. For this reason, DR's of relatively low dielectric constant are almost always used in antenna applications [4]. The bandwidth enhancement in DRA is most interesting area for researchers, there are several techniques was developed by many researcher e.g. using coupling mechanism like probe, slot & microstrip feed etc., stacking of DR with different permittivity materials, its aspect ratios, and DRA with air gap etc. (a) (b) Figure 1. Four-element and three layer cylindrical DRA with layered central dielectric cylinder fed by central coaxial probe. (a) Top view, (b) cross-section view at XX’ plane. 978-1-61284-091-8/11/$26.00 ©2011 IEEE