Interaction of Electromagnetic Transient Radiation with Biological Materials

The transmission characteristics of transient electromagnetic pulses in biological material are studied using a plane wave pulse incident normally on a semi-infinite layer model. With the dispersion properties of complex tissue dielectric constants taken into account, the steady state transfer function was examined as a function of frequency. Integral solutions for the transmitted field of a Gaussian pulse were obtained through Fourier transformation. The transmitted waveforms inside muscle were determined numerically for various depths pertinent to biological situations. The results suggest that incident pulse experiences severe reflection at the airtissue interface and, shorter pulses are transmitted more readily than longer ones. For an incident pulse of 50 kV/m and 1 us in pulsewidth, the transmitted amplitude is 221 V/m.