Eccentric annular slot patch antenna with frequency agility for UHF RFID reader applications |
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| Authors: | Lei Ge Chow‐Yen‐Desmond Sim Chuan‐Wei Lin Ting‐An Chen |
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| Affiliation: | 1. College of Electronic Science and Technology, Shenzhen University, Shenzhen, People's Republic of China;2. Department of Electrical Engineering, Feng Chia University, Taichung, Taiwan |
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| Abstract: | The design of a simple ultrahigh frequency RFID (radio frequency identification) reader antenna that can operate within the North America RFID band (902–928 MHz) is studied. To generate circular polarization (CP) radiation in this band, a novel method of loading two narrow open‐ended slots (slits) into an eccentric annular slot patch is proposed. To allow optimum impedance matching with enhanced CP bandwidth, the radiating patch is loaded to an L‐shaped ground plane. From the experimental results, the proposed antenna can yield an impedance bandwidth (10‐dB return loss) between 650 MHz to 1125 MHz, while good CP bandwidth (3‐dB axial ratio, AR) from 901 MHz to 930 MHz is also attained. Furthermore, gain level and efficiency of more than 7.8 dBic and 90%, respectively, were also measured. By simply removing one of the slits, this proposed antenna can also be modified to operate within the China (840–846 MHz) and European (865–868 MHz) RFID band. |
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| Keywords: | axial ratio circular polarization patch antenna RFID antenna |
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