Compact and Circular Polarized RFID Antenna for Portable Terminal Applications

<table>Comparison of S11 and AR of the antenna with different <svg height="15.4" id="M27" style="vertical-align:-3.3907pt" version="1.1" viewbox="0 0 21.75 15.4" width="21.75" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
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<g transform="matrix(.012,-0,0,-.012,9.763,15.187)"><path d="M452 333q0 -82 -46 -164t-116 -128q-81 -53 -158 -53q-26 0 -51 13t-37 32q-26 41 -6 134l91 431q7 40 2.5 47t-34.5 7h-33l2 25q36 4 72.5 13t58.5 15.5t28 6.5q10 0 4 -29l-91 -391h2q65 77 130 116.5t105 39.5q36 0 56.5 -32t20.5 -83zM365 316q0 76 -35 76
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</svg>. (a) S11. (b) Axial ratio. </table>

International Journal of Antennas and Propagation

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Figure 7

Figure 7: Compact and Circular Polarized RFID Antenna for Portable Terminal Applications 