Differential Method for Determining the Specific Absorption Rate of Electromagnetic Energy of a Liquid Phantom

The wide use of small-sized wearable electronic devices in various practical human activities makes it relevant to measure the proportion of electromagnetic energy absorbed by the human body. One of the most important parameters that determines it is the specific absorption rate. In this article the authors propose a method for determining this coefficient for a liquid phantom with the use of computer simulation and experimental measurement of the microstrip patch antenna parameters. The antenna is located on an elliptical cylinder and operates in the wireless medical body area network. The method is based on measuring the rise in temperature of the liquid phantom exposed to electromagnetic waves generated by a microstrip patch antenna over a certain time. Homogeneous liquid phantom was created by changing the percentage of salt and sugar in 250 g of water, the skin phantom — by changing the percentage of water in 200 g of glycerol. The proposed specific absorption rate measurement method eliminates the need to purchase an expensive set of dielectric probes, which demonstrates its cost-effectiveness. The results of experimental measurements are in good agreement with the results of the performed computer simulation.