Inductively Coupled Compact RFID Tag Antenna at 910 MHz With Near-Isotropic Radar Cross-Section (RCS) Patterns

Abstract

This letter presents a compact (0.12 x 0.14lambda) RFID tag antenna which has near-isotropic radar cross-section (RCS) patterns and easy conjugate impedance matching property by virtue of an inductively coupled feeding. Its measured maximum and minimum RCS' are -17.3 dBm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and -20.4 dBm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , respectively, with a difference of only 3.1 dB in all incident angles. The measured RCS' have been found to be in good agreement with simulation.