The basic geometry of the U-slot patch antenna is shown in Fig. 1. This antenna was introduced in 1995 by Huynh and Lee [1] as a single-layer, single-patch patch linearly polarized antenna with an impedance bandwidth exceeding 30% for an air substrate of about 0.08λo thickness. Since then, this design has been extensively studied [2]-[7], not only for wide band applications but also for dual-band and triple-band applications, as well as for circular polarization operations [8]-[9]. The purpose of this paper is to present results showing the versatility of the U-slot patch antenna, although only simulation results are given in this paper for brevity.