Maximization of the Operating Volume using HF RFID Loop Antennas

This article describes how a passive radio frequency identification (RFID) system is optimized. Our attention focuses on the operating volume of a circular loop antenna. Hereby the design of loop antennas is given a new approach to establish a maximum operating volume. Therefore, the off-axis magnetic field is investigated. This is done for a circular loop in free space and in the vicinity of a metal plane. A numerical approach is given towards the maximization of the operating volume. The goal is to provide new insights into the design of a loop antenna and enhance the reliability of the RFID system.