Compact wide band monopolar patch antenna

A compact wideband monopolar patch antenna, which is resonated by a multioperating structure, is presented. The multioperating structured antenna is constructed by a crossshape copper plate folded as an upward cap, excited by a square disc coupling feed. Without the folded upward wall, the antenna exhibits about 30% impedance bandwidth (SWR < 2). The upward wall provides an extra impedance bandwidth in the lower band. By choosing the certain height of the upward wall, the bandwidth can be enhanced appreciably up to 76% (SWR < 2) from 1. 74 to 3.87 GHz. The antenna exhibits a stable gain around 4 dBi and radiation patterns in the whole operating frequency. The resonance length reduction is 63% when compared with the conventional TM01 mode (one wave length) patch antenna. Experimental results show a good agreement with the simulation results obtained by IE3D. (C) 2007 Wiley Periodicals, Inc.