Miniaturized RFID Tag Antenna Operating at 915 MHz

A novel miniaturized radio frequency identification (RFID) tag antenna is introduced in this letter. The antenna is designed to operate at 915 MHz. Its electrical size is (λ
₀
/30)×(λ
₀
/30), which makes it among the smallest antennas presented in literature. The new antenna has a “Vivaldi-like” aperture fed with a slot line coupled electromagnetically to a microstrip line. The aperture is loaded with a meander line. The new antenna is thoroughly investigated both theoretically and experimentally. It enjoys a number of appealing characteristics, such as compact size, low profile, flexible impedance tuning, good impedance bandwidth, omnidirectional radiation patterns, low cross-polarization level, and reasonable gain.