THE EFFECTS OF A NEARBY BIOLOGICAL BODY ON THE PARAMETERS OF A SMALL HAND-HELD TRANSMITTER OPERATING IN THE HF BAND (3-MHZ-30-MHZ)

The effects of a nearby biological body on the efficiency and radiatio n patterns of a small hand-held radio operating in the H.F. band are d etermined by computer modeling. The close proximity of the radio opera tor's body results in the scattered field from the body reradiating an d perturbing the known free-space current distribution on the antenna to some extent. However, due to the extremely small electrical size of the radiating system, this body-to-radio coupling is assumed to be mi nimal and hence forth neglected. Thus, a direct moment method is used to solve a volumetric electric field integral equation with the near f ield of the radio used as the excitation field Once the equivalent vol umetric currents are determined, the efficiency and radiation patterns are found using these currents and the unperturbed free space current of the radio antenna.