An Asymmetrical Feed Arrangement for Improved Impedance Bandwidth of Planar Monopole Antennas

The use of an asymmetrical feed probe is shown to significantly increase the impedance bandwidth of a square planar monopole antenna. The feed probe is offset from the center of the planar element. The optimum location of the feed probe is shown to increase the impedance bandwidth by a factor of 3.4. The effect of the asymmetry on radiation patterns is also shown.