Dependence of electromagnetic energy distribution inside a typical multilayer fruit model on direction of arrival and polarization of incident field

Abstract

Global electromagnetic regulatory organizations have prescribed guidelines to protect humans from short duration immediate health effects of electromagnetic exposure. In this connection, maximum permissible limits for Specific Absorption Rate and power density have been prescribed respectively in near field and far field regions. However, prescribing reference power density level for far field exposure is insufficient because direction of arrival and polarization of incident field crucially impact electromagnetic energy absorption in biological bodies. On the other hand, plant and fruit tissues also possess reasonably high permittivity and electrical conductivity; but unfortunately, no standardizing organization has shown interest in limiting electromagnetic energy deposition in vegetation by implementing regulatory guidelines. Combining both of these issues together, this article aims at investigating electromagnetic energy absorption rate inside a typical multilayer fruit model and its dependence on direction of arrival as well as polarization of incident electromagnetic wave. Specific Absorption Rates have been evaluated as per one of the international standards at 947.5 MHz and 1842.5 MHz. Wide discrepancies among observed Specific Absorption Rates due to varied direction of arrival and polarization suggests direct adoption of Specific Absorption Rate limit instead of power density reference limits in far field region.