—Based on the current distribution on the parallel microstrip lines and emission cancellation characteristic of close equal and opposite currents

a novel balun structure for dipole antenna is proposed. In this paper

the principle of the balun structure is elaborated and verified. Then a dipole antenna with resonance at 2.45GHz constructed with the balun is fabricated and measured. The simulated and measured reaction coefficient(S11) of the antenna are in good agreement over 2~3GH. The relative bandwidth with S11 of below -10dB is more than 25%. The antenna also shows a good radiation pattern at 2.45GHz. The structure can provide a new balun design method for dipole antennas.