Octafilar helical antenna for handheld UHF RFID reader

Octafilar helical antenna (OFHA) is proposed for handheld ultra-high-frequency (UHF) radio frequency identification (RFID) reader. The investigated antenna configuration consists of OFHA placed on reader device in the presence of human hand model. The antenna is designed at UHF band centred at 915 MHz. The antenna return loss, axial ratio, gain, co-polarized and cross-polarized field components are calculated using the finite element method (FEM) and compared with that calculated by finite integration technique (FIT) for verification of the simulated results. A comparison between the performance of the quadrifilar helical antenna (QFHA) and the octafiliar helical antenna (OFHA) designed at 915 MHz in the presence of the reader device and human hand model is investigated. The OFHA introduces high gain, high front to back ratio, good axial ratio and omnidirectional coverage.