Narrow waveguide-slot radiator filled with layered dielectric

Narrow slots in waveguide walls are widely used in super high frequency technique as coupling elements or antenna radiators. Their physical properties are well studied theoretically and experimentally and described in scientific literature. But the techniques development requires broadening of slot performing possibilities, for example control of its resonance frequency. For this purpose the slot can be completely or partially filled with dielectric. The way of scattering problem solving for fully filled slot does not differ from one in the case of empty slot. When the slot is partly filled with dielectric some difficulties of their study appear. This problem was solved in [1] for such slot coupling two half-infinite rectangular waveguides over their common end wall. In [2] the similar problem was solved when the transverse slot with dielectric slab couples two infinite rectangular waveguides over their common broad wall. Of great interest are the scattering and directional properties of above mentioned slot radiating into free half-space. The following report deals with this question.