A dielectric loaded microstrip patch antenna is provided for delivering relatively wide operational bandwidth dual-band, with relatively good isolation and flexibility for circular polarization, while having a compact design and lightweight to suit mobile and wireless applications. The microstrip patch antenna has a conducting ground plane and a patch radiator. The patch radiator is spaced from the ground plane by a substantial distance having a first dielectric material therein. A slot feed in the grou nd plane provides the patch radiator with radio signal energy across the space having the firs t dielectric material therein. A piece of a second dielectric material is disposed adjace nt the slot feed between the patch radiator and the ground plane. The second dielectric material has a dielectric constant that is higher than the dielectric constant of the first dielectric material. The piece of the second dielectric material acts to load the feed in order t o improve coupling between the slot and the patch. The piece has a dimension along one of the x and y axes smaller than a dimension of the patch along a same axis. Since th e piece is situated between the ground plane and the patch it determines operational characteristics of the microstrip patch antenna.
