It is possible to explain influence of electromagnetic waves on biological objects their resonant properties. The big practical value has a question of influence of electromagnetic waves on grains. In this case it is useful to know own frequencies of electromagnetic oscillations of grain. It is possible to present grain in the form of the open dielectric three-layer resonator representing ellipsoid of rotations.
For simplification of calculations at a finding of own frequencies it is necessary to solve the equations of Maksvell in spheroidal coordinates – in this case boundary conditions will depend only on one coordinate. It is more convenient to use the extended spheroidal coordinates – they turn out by rotation of an ellipse round an axis passing through its focuses. Variables in the Maksvell equations can be divided, using potentials of Abragam. The decision are the extended spheroidal functions. From a condition of a continuity of fields on border of section of environments it is possible to receive a transcendental parity for calculation of wave numbers and own frequencies. The received numerical values of spheroidal functions were compared to tabular values, deviations have made less than 1 %.
For calculations were set cross-section (diameter – 1 – 3 mm) and longitudinal (length – 3 – 8 mm) the sizes of grain. Relative di-electric permeability of grain lies in a range 3 – 10. Own frequencies depending on the sizes of grain and dielectric permeability have appeared lying in a range 15 – 60 GHz. At increase in dielectric permeability distinction between frequencies of electric and magnetic oscillations decreases.