Patent ID: 7002519

Claim:
A method of independently modifying the ¼ and/or the ¾ wavelength resonant frequency in an open-ended slotted PIFA antenna, an open-ended slotted PIFA antenna comprising an antenna ground associated with the antenna short-circuit end, and an open-ended slot having an open-end associated with the antenna open-circuit end, and wherein the antenna ground and the slot are mutually arranged to provide operational variations in the current density between the open and short circuit ends of the antenna and around the perimeter of the slot, and to provide an operational mean current path length between the open and short circuit ends of the antenna and around the perimeter of the open-ended slot, the mean current path length determining the ¼ and ¾ wavelength resonant frequencies for the open-ended slotted PIFA antenna, the method comprising determining operational variations in current density around the perimeter of a pre-modified open-ended slotted PIFA antenna and modifying the mean current path length around the perimeter of the pre-modified open-ended slot in regions of comparatively high current density.