Near-field measurement of transmit antenna factor of small dipole antenna in saline solution

To determine E-field at a tip of probe for evaluating SAR (specific absorption rate) values of DUTs in saline solution, use of near-field transmit antenna factor (NF-TAF) of small dipole antenna is proposed. NF-TAF can be expressed in closed form by assuming hyperbolic sinusoidal current distribution. Also, it can be evaluated by measuring S parameters between two identical dipole antennas and dielectric property of the saline solution. Calculated and measured NF-TAF are compared with each other, and limited range of antenna distance should be used for accurate calibration of E-field probe in the saline solution at 6.78MHz.