Radiation mechanism of H-shaped antenna using parallel resonance mode

It is required to work in various surrounding environments in order that the small antennas used for mobile terminal and RFID tag are located in the vicinity of various objects including the human body and the metal. H-shaped antenna has been proposed to obtain the characteristics not to be changed by circumference environment. The H-shaped antenna has been designed by adjusting offset position and the ratio between the lengths of parallel elements. As a result of examination about the antenna height (h), the shift of input impedance near the metal was the smallest when h = 0.04¿.