Small-size wide-bandwidth microstrip patch antennas

In many applications in wireless communications, it is desirable to use microstrip patch antennas which are small in size but have bandwidths in excess of 10%. There are three common methods of reducing the patch size: (1) the use of microwave substrates with large permittivities; (2) the use of shorting walls; and (3) the use of shorting pins. When applied to the regular patch, the resulting small-size antenna usually has only a few percent bandwidth, not enough to meet the requirement of many applications. In this paper, we apply the three size reduction techniques to two wideband patch antennas - the U-slot patch and the L-probe patch. Simulation results using ENSEMBLE 6.0 are presented first, followed by some measured results.