Integrated antennas for hand-held telephones with low absorption

Antennas for hand-held telephones must have high efficiency due to the limited power available, and recent demands call for integrated antennas in hand-held telephones. A full short circuit planar inverted-F antenna (FS-PIFA) is investigated, which concentrates the current near the antenna, and has a relatively higher gain directed away from the user´s head thereby reducing the losses in the human body, which is important from the point of view of efficiency and possible health hazards. For design and analysis of the antenna including parts of the human body the finite difference time domain (FDTD) method is employed, and measurements of average received power and spatial peak specific absorption rate, SAR, values were performed, to verify simulation results. Measurements of the antenna gain in realistic environments with a person showed a gain about 2 dB less than a half wavelength whip on the same telephone, while the local SAR was typically 0.1-0.2 mW/cm³, a factor of ten smaller than present standards and handportables