Compact folded patch antenna for UHF RFID

摘要

A miniature folded patch antenna, which has a dimension of 30 mm × 30 mm × 1.6 mm (0.092λ × 0.092λ × 0.0047λ), is proposed for designing a passive ultra-high frequency (UHF) tag. Tag miniaturization can be easily achieved by stub-shorting two triangular patches to the ground and by inserting two narrow notches on both sides of the patches. Maximum realized gain of -9.97 dB is obtainable at the resonant frequency of 920 MHz. When placed on a dielectric object with permittivity value in the range of 1-12.4, the tag has very little fluctuation in the resonant frequency.