Dual Band UHF and Microwave RFID Antenna

This paper presents a new topology for RFID antenna matched on all UHF and one of the microwave RFID´s band. The antenna can be implemented on different standards of tag´s sizes as credit card, 85 times 54 mm, or other common sizes 50 times 50 mm. The most criticals parameters of the antenna are studied in order to predict design rules for implemented different kind of dies on the antenna. Radiation pattern on UHF band is complementary to the radiation pattern on microwave band. The substrate is FR4, 0.8 mm, with epsiv_r = 4.4. Some purposes are made on future studied of a tri-band antenna on 13.56 MHz, all UHF and 2.45 GHz RFID´s band.