RFID tag antenna mountable on metallic surfaces and matching method by parasitic patches

A low cost novel antenna for radiofrequency identification (RFID) tags mountable on metallic surfaces has been proposed and implemented. The proposed antenna indicates not only an easy impedance matching method with various microchip impedances but also the ability to be mounted on metallic surfaces. In this paper, the folded dipole type tag antenna with two parasitism-patches is proposed. This allows control of both the real and imaginary parts of the antenna impedance to achieve conjugate matching with the various values of the microchip impedance.