Capacitively loaded loop antenna fed by wideband metamaterial balun

A capacitively loaded loop antenna fed by a wideband balun has been designed for a possible use as a near field RFID UHF reader. The balun bandwidth is about 88 % based on phase balance and the loop antenna bandwidth is approximately 6.5 %. The simulated current distribution on the capacitively loaded loop antenna is quite uniform to ensure high magnetic field intensity at the loop center.