Matching Techniques for Miniaturized UHF RFID Loop Antennas

Two types of matching techniques are proposed for the UHF RFID antennas in Korea. One is to create dual-resonance mode inside loop antenna, and the other is to use folded dipole loop antenna with capacitive loading. The measured maximum gains are -2.9 and 1.8 dBi, respectively. In both cases, the measured bandwidths are 6 and 8 MHz. The proposed antenna has achieved 80% size reduction compared with a one-wavelength long loop antenna.