A novel frequency/pattern-reconfigurable microstrip antenna for WLAN applications

The design of a frequency and pattern reconfigurable monopole-type printed antenna is presented in this paper. The antenna features a circular patch fed using a microstrip line, a shape-optimized partial ground plane, and two PIN diodes mounted over two slots in the ground plane. Three switching cases are considered. The first results in a single-band operation at 5.2 GHz, whereas the other two cases offer a dual-band operation, at 2.4 GHz and 5.2 GHz. In all three cases, an omnidirectional radiation pattern is obtained in the 5.2 GHz band. However, in the two cases where operation at 2.4 GHz is possible, an equal-gain E-plane pattern and 180°-switchable H-plane patterns are offered depending on the switching condition.