Ultrabroadband printed (UBP) antenna

An ultra broadband printed (UBP) antenna is presented which consists of a diplexer and two aperture stacked patch antennas. S-parameter theory is used to investigate the input impedance behavior of the UBP antenna. This antenna can produce a 10-dB return loss bandwidth of almost 120% with constant gain of 6.5 dB. A relatively uniform radiation pattern over the entire band was also achieved.