DIELECTRIC AND GEOMETRIC DEPENDENCE OF ELECTRIC-FIELD AND POWER DISTRIBUTION IN A WAVE-GUIDE HETEROGENEOUSLY FILLED WITH LOSSY DIELECTRICS

In microwave processing of dielectric materials which completely fill a waveguide, the distribution of the electric field within the materia l needs to be known, This paper presents the theoretical conditions fo r the microwave cure of large pieces, the size of which is more than t he wavelength, The mathematical description of heterogeneously multila yer-filled waveguides presents certain difficulties because of the inv olved transcendental equations. A computer treatment to determine the electric-held spatial distribution is developed, The influence of the dielectric constants and the thickness of the dielectric materials on the spatial distribution of the electric field and power how in each l ayer is studied, In particular, the field strength is enhanced in the dielectric with the highest permittivity. A numerical resolution of th e transcendental equations defining the cutoff frequencies of propagat ion modes allows one to enumerate the modes, which can successively ap pear in a dielectric-loaded waveguide as functions of dielectric and g eometric parameters, The attenuation constant and the microwave power dissipated in each material are determined, A balance sheet of energy is established.