Tae-Wan Kim

Bio: Tae-Wan Kim is an academic researcher. The author has contributed to research in topics: Dielectric resonator antenna & Microstrip antenna. The author has an hindex of 1, co-authored 1 publications receiving 3 citations.

Enhanced gain and miniaturisation method of stacked dielectric resonator antenna using metallic cap

Abstract: The authors introduce a miniature and gain enhancement method of dielectric resonator antenna (DRA) using a metallic cap. The structure of the proposed antenna consists of a stacked cylindrical dielectric resonator, a metallic cap that is located on the resonator, and a ground plane. By adjusting the size of the metallic cap while retaining the size of the antenna, the proposed antenna operates in the lower frequency band and shows improved realised gain. As the radius of metallic cap increases, wavelength at z -axis increases and the resonance frequency gets lower. In addition, tangential field at side wall surface increases, which leads to the enhancement of realised gain at resonance frequency. The authors have fabricated a prototype of the antenna for the experimental verification. The simulation results are in a close agreement with the experimental finding.

Wideband circularly polarized low profile dielectric resonator antenna with meta superstrate for high gain

Abstract: A low profile circularly polarized high directive Dielectric Resonator Antenna (DRA) is presented for X - band wireless applications. DRA is excited by microstrip aperture slot coupling which is employed on the bottom side of the substrate. Two asymmetric rectangular split rings are created adjacent to the feed line on the substrate to enhance the 3-dB axial ratio bandwidth and impedance bandwidth. Corrugated circular ring shaped single layer double sided meta superstrate is loaded on the DRA to enhance the peak gain to 11.9 dBi. The extracted lumped element model of the Superstrate unit is found to be in concurrence with Electromagnetic (EM) simulations. The proposed geometry offers a 1.1 GHz axial ratio bandwidth with 2.6 GHz impedance bandwidth. A prototype is fabricated and experimentally verified.

Filtering Quasi-Yagi Strip-Loaded DRR Antenna With Enhanced Gain and Selectivity by Metamaterial

Abstract: This paper presents a design approach of broadband filtering quasi-Yagi DRR Antenna using a strip-loaded dielectric ring resonator (DRR) and near-zero-index (NZI) metamaterial (NZIM). The ring strip is loaded to the inside wall of the DRR so that the TE $_{01 \delta }$ and TE $_{21\delta }$ modes of the DRR can be close. Meanwhile, they function as a dual-mode magnetic dipole (M-dipole) driver and can be differentially excited at the same time for designing a wideband quasi-Yagi antenna. Benefiting from the dual-mode operation of the strip-loaded DRR, the end-fire gain across the operating band of the antenna is stable with preliminary bandpass filtering characteristics. To improve the in-band gain and enhance the filtering capability, a new coplanar NZIM with wideband NZI characteristic and dual transmission notches in the lower and upper stopbands of the preliminary gain passband, is introduced and put in the front of the DRR driver. To verify the proposed design concept, an X-band filtering quasi-Yagi antenna with the NZIM is fabricated and measured. Good agreement between the simulated and measured results can be observed. The wideband antenna has a measured −10 dB impedance bandwidth of about 16% (8.5 – 10 GHz). Within it, the peak gain of antenna reaches 8.3 dBi and 1-dB gain fractional bandwidth is about 10.8%. Meanwhile, it exhibits good gain bandpass response due to the transmission notches of the NZIM.

Dual-Fed C-DRA Loaded by Modified Circular Patch Antenna

Abstract: This paper presents a cylindrical-dielectric resonator antenna (C-DRA) loaded by a circular patch for emerging wide-band wireless communications. To generate a polarization diversity pattern, the proposed antenna is fed by two orthogonal aperture-coupled feeding slots. The slots' shape and position were chosen to achieve the best operating bandwidth and isolation between the two feeds. A circular patch with crossed dumbbell-shaped slots was etched to achieve high polarization purity. Ansys EDT full wave simulator was used to design and optimize the proposed antenna. Simulation results demonstrate that the proposed antenna achieves a 2 GHz impedance bandwidth (26.64 GHz – 28.69 GHz) centered at 27.6 GHz, with isolation between the two feeding ports better than 25 dB over the operational bandwidth, implying that the antenna can achieve pure diverse polarization (Axial Ratio (AR) less than 0.1 dB) with total gain more than 6 dB over the operating frequency bandwidth. The proposed antenna is a good building component for the next 5G wireless communications technology as well as Ka-band satellite communications.

A Miniaturized Wide Beamwidth Dielectric Resonator Antenna

Abstract: A miniaturized wide beamwidth dielectric resonator antenna is presented. The wedge-shaped concave structure is introduced to enhance the phase delay between the different positions on the same aperture. Some metal patches are attached on the side walls of concave structure and the top of dielectric resonator antenna to miniaturize the antenna. The resonant frequency of the proposed antenna can be reduced by 26.2%, with excellent half-power beamwidth performance of 165.4° and 179.8° in the E- and H-planes at 24 GHz, respectively.

Synthesizing Radiation Properties of Dual-band Dual-mode High Gain Dielectric Resonator Antenna for Wireless Applications

Abstract: |In this article, the radiation properties of a slot-loaded cylindrical dielectric resonator antenna (CDRA) have been analyzed strategically to realize a dual-band operation with a higher gain. A microstrip line based aperture coupled feed is adopted to excite dual modes at 4.8 GHz and 8.28 GHz with an impedance bandwidth of 5.84% (280 MHz) and 10.62% (880 MHz), respectively. A superstrate layer is placed at a suitable gap above the antenna structure to enhance the antenna gain by utilizing the principle of multiple re(cid:13)ections. For the further improvement of gain, a plus-shaped slot is incorporated on the superstrate that helps to concentrate the radiated (cid:12)eld at the center of the superstrate, thereby the directivity of the CDRA has been enhanced on a large scale. The proposed structure is fabricated and measured for experimental veri(cid:12)cation that demonstrate 3 dB augmentations in antenna peak gain in comparison to the conventional CDRA. The experimental result shows a good agreement with the simulated ones. Higher measured peak gains of 7.87 dBi and 7.91 dBi at two operating bands ensure the applicability of the proposed simple structure for high gain wireless applications.