Wideband and reduced size microstrip slot antennas for wireless applications

In present wireless communication applications, mobile units, e.g. mobile handsets, PC cards and other hand held devices, require miniaturized antennas, but with good functionality. Microstrip antennas can be made smaller by means of conventional miniaturization techniques. However, they offer only a few percent impedance bandwidths, whereas the growing demand is for wideband antennas to transmit large volume of information. Microstrip slot antennas, have the potential to provide wide bandwidths. Moreover, they do not add weight and size to the system. Two new designs of microstrip slot antennas, an L-slot antenna and an inverted T-slot antenna, are presented, aiming to attain wider bandwidths with shorter vertical lengths. These geometries exhibit bandwidth in excess of 80% with nearly omnidirectional radiation patterns. Their small size provides a large portion of the small ground plane for electronics to be incorporated on the same substrate. Good agreement is demonstrated between the simulated and measured results.