A Novel Half Hemispherical Dielectric Resonator Antenna With Array of Slots for Wideband Applications

Abstract

Abstract-A novel half Hemispherical Dielectric Resonator Antenna (HDRA) with an array of slots has been designed. The dielectric material used is Rogers TMM10, which is a ceramic thermoset polymer composite material having a dielectric constant of ε r = 9.2. Periodic holes lower down the Q factor of the antenna and hence enhance the impedance bandwidth. The measured value of the 10 dB bandwidth is close to 1 GHz (∼17.74%). The mode investigated is a TM 101 like mode. Further, the effect of increasing the probe length on the resonance and the radiation pattern is also studied. As the probe length is increased, a shift in the resonant frequency is observed and the Dielectric Resonator Antenna (DRA) behaves as a monopole antenna loaded with the DRA. The experimental results confirm that a wide bandwidth of 1.3 GHz (∼29%) with a high gain of 7.2 dBi can be obtained. The radiation pattern of such an antenna is directive in nature.

Design and its state‐of‐the‐art of different shaped dielectric resonator antennas at millimeter‐wave frequency band

“…Luk et al have described an analysis of hemispherical DRA with a coaxial probe using green's function. Similarly, Mukherjee et al presented a half hemispherical DRA with an array of slots for wideband applications with an impedance bandwidth of 1.3 GHz and realized gain of around 7.2 dBi at 4.55 GHz. Mcallister et al presented a numerical validation of hemispherical DRA, as shown in Equation : where, f r is the resonant frequency, a is the radius of DRA, and ε r is the permittivity of DRA.…”

“…This is mainly attributed to the fact that DRAs do not suffer from conduction losses and characterize by high radiation efficiency, when the feed is excited properly. For bringing a new horizon, an overview of basic shapes DRAs and a complete state‐of‐the‐art for mm‐wave DRAs are presented, as a comparative focus. Then, a working methodology in the form of design, simulation, and analysis of basic shaped DRAs at 60 GHz mm‐wave frequency band are reported.…”

Recent developments in bandwidth improvement of dielectric resonator antennas

“…Broadly, these approaches can be divided into four categories; firstly, according to the antenna geometry (DR shape/fractal/EBG/metamaterial), secondly, the coupling mechanism (feeding type/aperture shape), thirdly, the DR permittivity, and lastly, according to the excitation of specific mode. From ease of readers' point of view, these techniques are discussed separately for single‐band, dual‐band, and multi‐band,, respectively. Moreover, some other characteristics say radiation/notch…”

A Compact Wideband Rectangular Dielectric Resonator Antenna using Perforations and Edge Grounding

“…The bandwidth of the RDRA can be improved by lowering down the quality factor [2]. In [15], [16] symmetrical array of slots (perforations) is drilled all over DRA which improved bandwidth significantly. The judicious selection of size of slots and distance between two consecutive slots may preserve the fundamental mode of the DRA.…”

“…Various other methods where either feed or DR shape is modified such as creating a slot in the bevel shape feed for notch [13] and dual feed for covering two different bands [14] do not address the problem of compactness of a DRA. Interestingly perforations on DRA [15], [16] tend to improve bandwidth with antenna weight reduction but no compactness could be achieved. Therefore there is a tradeoff between size of the DRA and bandwidth offered.…”