A UHF RFID reader antenna with near field inductive wireless power transfer feature

An RFID reader antenna with truncated segmented coupling elliptical loop is proposed to operate at UHF band. The segmented coupling rings are used to achieve inductive wireless power transfer (WPT) while communication. The proposed UHF reader antenna has an input impedance matching bandwidth (S11 <; -10 dB) of 60 MHz (890-950 MHz) with the highest gain reaching 3.8 dB at 915 MHz. The WPT feature during communication makes the proposed antenna desirable for some special RFID applications such as implantable medical device without battery.