1 | Page Comparison of Rectangular Dielectric Resonator Antenna Modes using Microstrip Line Feeding at 26GHz Nida Nasir 1 , Mohd Haizal Jamaluddin 2 , and Nor Hidayu Shahadan 3 1,2 Wireless Communication Center (WCC), Faculty of Electrical Engineering,Universiti Teknologi Malaysia 3 Electrical Engineering Department, Politeknik Ibrahim Sultan. Pasir Gudang, Johor. nida@graduate.utm.my, haizal@utm.my, norhidayu@pis.edu.my Abstract — In this paper, a study on the Microstrip line feeding technique is done for fundamental mode and higher order mode for single element rectangular dielectric resonator antenna(RDRA) at 26 GHz for 5G and millimetre-wave applications. The dielectric resonator has a dielectric constant of 10 with a loss tangent of 0.002 and is etched on Rogers RT/Duroid 5880 substrate having a thickness of 0.254mm and relative permittivity of 2.2 with a loss tangent of 0.0009. The proposed structures are optimized and simulated using the Ansys HFSS (high-frequency structure simulator) software. The effect of feeding on the bandwidth, S11, gain, and radiation pattern are also examined and analyzed. The simulated results show that the microstrip line provides good performance in terms of high gain in higher order mode while wide bandwidth in fundamental mode and is found suitable for 5G applications. Index Terms —Rectangular Dielectric resonator antenna (RDRA), fundamental mode, higher order mode, microstrip line (ML). I. INTRODUCTION With recent advancements in mobile applications and users, the 5G band serves as a good option for mobile and satellite communication with high speeds and low latencies[1]. The millimetre-wave technology 5G (Fifth Generation) has been considered a promising network for high data rate, large bandwidth and high gain so more devices can be connected. 5G Band N258 [2] is a frequency band for millimeter-wave communication in 5G-NR New Radio networks with operating frequency bands 24.25 to 27.5 GHz (K-band). It is intended for short-range transmission at high data rates due to the availability of spectrum allowing several hundred megahertz to be dedicated to 5G services. In addition, this bands offer better propagation and reduced device complexity. Since 5G (mmWave) range use higher frequencies and requires placing base stations every few hundred meters while the signals cannot penetrate objects like cars, trees, and walls, because of the nature of electromagnetic waves. They can be used in smart buildings and cities, vehicles, and transportation services. For better coverage, and to obtain high directivity and gain, antenna arrays, MIMO and beam-steerable antennas are needed for the 5G mobile communication.  =    [ 1 +      ( )(   )] (1) The expression of the channel capacity[3] shows that higher data rates is only possible when operating bandwidth (B) is increased and the antenna gain at the transmitter or receiver (Gtx, Grx) is enhanced and by improving the signal- to-noise ratio (Pt/No). So, to improve the channel capacity in 5G, requirement is high-gain antenna to compensate for the propagation losses at the desired frequencies and wide bandwidth. To achieve better gain, large bandwidth, and high efficiency, DRA is suitable to use [4][5]. Since the bandwidth of a DRA depends on its aspect ratios, a rectangular-shaped DRA provides more flexibility in terms of bandwidth control. RDRA offers freedom of choice to select from its aspect ratios (length/height and width/height) [6], however, there are different shapes of DRA like cylindrical and hemispherical, but they do not offer design options. In addition, DRA has a 3D shape while microstrip antennas are 2D and monopoles are 1D. Additionally, microstrip antennas are metal devices and have losses like conductor loss and surface loss at high frequencies, consequently, it provides less gain and bandwidth instead they have advantages like low cost and lightweight. Comparatively, DRA offers advantages such as no conductor loss and surface wave losses due to the use of dielectric material [7]. Furthermore, it is low cost, lightweight, with ease of excitation, wide band, moderate gain(6dB) in fundamental mode, and high radiation efficiency [8][9][10]. The reason for the wide bandwidth in DRA is it radiates through the whole surface except the ground while Microstrip Patch antenna radiates through two narrow radiation sides [7]. Due to the absence of conducting material, the DRAs are characterized by high radiation efficiency when a low-loss dielectric material is chosen. The size of the DRA is proportional to o/√ with o =/o being the free-space wavelength at the resonant frequency o and  denotes the relative permittivity of the material forming the radiating structure. The resonant frequency of the DRA [11] is determined using the dielectric waveguide model (DWM) by using equations 2,3 and 4. ky tan(ky w/2) = )(ϵr − 1)ko  − ky  (2) kx  + ky  + kz  = ϵr ko  (3) kx = 0 1 kz= 2 3 ko = 4 5 (4) Where fo is the resonant frequency in (GHz), ko is the free space wave number, c is the velocity of light (2.998x10 +11 mm/sec) and kx, ky, and kz represents the wave number along the x, y and z directions, respectively. 6, 7 are half-wave field variation along x and 8 direction. The dimensions, w, d, and h in a single DRA based on a rectangular shape are illustrated in Figure 1. 978-1-6654-8977-5/22/$31.00 ©2022 IEEE 2022 IEEE International RF and Microwave Conference (RFM) 2022 IEEE International RF and Microwave Conference (RFM) | 978-1-6654-8977-5/22/$31.00 ©2022 IEEE | DOI: 10.1109/RFM56185.2022.10065189 Authorized licensed use limited to: UNIVERSITY TEKNOLOGI MALAYSIA. Downloaded on November 13,2023 at 13:27:43 UTC from IEEE Xplore. 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