Double Whorl Loaded UHF RFID Tag Antenna

To achieve a small size, a novel ultra-high frequency radio frequency identification (UHF RFID) tag antenna with a double-whorl structure is proposed. The antenna consists of ox horn shaped radiation elements, two symmetrical irregular whorl radiation elements, and two symmetrical metal strips with a thin dielectric substrate. These features bring the antenna quasi omnidirectional radiation characteristics. The double-whorl loaded tag antenna has the advantages of simple structure, small size (36 × 18 mm
²
) with a gain of 1.66 dBi, low cost, flexible substrate and easy mass production.