Sungwoo Lee

Hybrid Robust Optimization for the Design of a Smartphone Metal Frame Antenna

Hybrid robust optimization that combines a genetical swarm optimization (GSO) scheme with an orthogonal array (OA) is proposed to design an antenna robust to the tolerances arising during the fabrication process of the antenna in this paper. An inverted-F antenna with a metal frame serves as an example to explain the procedure of the proposed method. GSO is adapted to determine the design variables of the antenna, which operates on the GSM850 band (824–894 MHz). The robustness of the antenna is evaluated through a noise test using the OA. The robustness of the optimized antenna is improved by approximately 61.3% relative to that of a conventional antenna. Conventional and optimized antennas are fabricated and measured to validate the experimental results.

A Compact, Low-Profile Log-Periodic Meandered Dipole Array Antenna with an Artificial Magnetic Conductor

A compact and low-profile log-periodic meandered dipole array (LPMDA) antenna with an artificial magnetic conductor (AMC) is proposed. For compactness, a meander line configuration is implemented with dipole elements and optimized using a genetic algorithm (GA) to realize the LPMDA antenna. As a result, a size reduction of approximately 30 is achieved as compared to a conventional log-periodic dipole array antenna. To enhance the gain characteristics, the AMC ground plane configuration is realized with 9 × 9 unit cells for the LPMDA antenna. Two prototypes of the proposed LPMDA antennas with and without an AMC are fabricated and measured to verify its performance. The measured −10 dB reflection ratio bandwidths are 2.56 : 1 (0.85–2.18 GHz) and 2.34 : 1 (0.92–2.16 GHz) for the proposed LPMDA antennas with and without the AMC, respectively. The gain at the main beam direction within the operating frequency bandwidth is significantly improved from 3.94–7.17 dBi to 7.86–10.01 dBi by applying the AMC.

A novel robust design method for a mobile antenna with a metal frame

This paper presents a novel robust design method for a mobile antenna with a metal frame. In order to improve the robustness of the antenna against the tolerance occurred in the fabrication process, the proposed robust design method combines genetical swarm optimization with an orthogonal array. The robustness of the optimum model is better than that of the conventional model by 21%.

Circularly polarized CHANEL-logo antenna for GNSS applications

Abstract In this study, a wearable CHANEL-logo antenna with circular polarization for global navigation satellite system (GNSS) applications is proposed. A leather substrate and EM-271S silver paste are used to fabricate the proposed antenna. In order to produce circular polarization while maintaining the configuration of the CHANEL-logo, a circular slot is embedded on a ground plane and a coplanar waveguide feed scheme is used. As a result, the proposed antenna produces right-hand circular polarization. A prototype of the proposed antenna is fabricated and measured to assess its performance. The measured dB reflection and 3 dB axial ratio bandwidths of the proposed antenna are approximately 4.4% (1.555–1.625 GHz) and 3.14% (1.565–1.615 GHz), respectively. The measured peak gain of the fabricated antenna is dBic.