Performance Evaluation of a Compact Electrically Small Antenna with Ka < 1 for UHF RFID Systems

Abstract

This research paper presents a comprehensive analysis of low-profile electrically small antennas designed specifically for Radio Frequency Identification (RFID) applications with a size parameter Ks less than unity. The study investigates the fundamental limitations, design methodologies, and performance characteristics of miniaturized antennas operating in the Ultra High Frequency (UHF) RFID band. Through theoretical analysis and simulation studies, this work examines the trade-offs between antenna size, efficiency, and bandwidth while maintaining acceptable radiation characteristics. The research focuses on overcoming the inherent challenges of electrically small antennas, including narrow bandwidth, low radiation efficiency, and impedance matching difficulties. Novel design approaches incorporating metamaterial structures and fractal geometries are evaluated to enhance antenna performance within the stringent size constraints. The findings demonstrate that carefully designed low-profile antennas can achieve reasonable performance for RFID applications despite the fundamental limitations imposed by the Wheeler-Chu limit. This work contributes to the advancement of compact antenna technology for modern wireless communication systems and provides insights into the optimization of electrically small antennas for practical RFID implementations.