On the Penetration of UHF Energy Through the Head

Abstract

We present here our calculations on energy level shifts through the various layers of tissue in a forehead model using as initial data the rf hearing data. If the rf hearing phenomena requires the conversion of rf energy into some other form of energy (possibly electrical energy in the video modulation spectrum, or energy of mechanical vibration), and if the conversion efficiency is assumed to be constant at any rf carrier frequency from 100 MHz to 10,000 MHz; then it would be possible to calculate the depth, within the head, at which the rf conversion mechanism lies. That is, the existing literature contains experimental data taken for a number of different carrier frequencies, giving the measured rf power re-quired to experience the rf hearing effect at its minimal, or threshold level. Under the assumption of constant conversion efficiency, there is one mechanism to explain why one radio frequency requires more power than a second radio frequency to achieve threshold conditions---the kind describing radio propagation losses.