Novel circular polarization antenna for a UHF bandwidth RFID reader

This study designed a new circular polarization wave that separates original signals into two signals with phase difference of 90deg using hybrid coupler with 0.16 dB insert loss and phase difference of 90deg and provides them for two strip lines with a length of lambda/2 to realize circular polarization wave reader proposed in this study. This study designed a radiation plate with cross section of 13.4 cm times 13.4 cm having two feed points using phase difference of 90deg to improve power efficiency.