Admittance characteristics of narrow radiating slots in nonradiating dielectric waveguide

A study of an inclined slot cut in the metal wall of nonradiative dielectric (NRD) waveguide is presented. The modal expansion method is applied to the development of an equivalent network of a slot discontinuity in NRD waveguide, using the reciprocity and Poynting theorems. The effect of the metal wall thickness is taken into consideration by applying microwave network analysis. Numerical data for the normalised slot admittance is obtained and compared with experimental results. Good agreement is observed. Numerical data for the slot admittance for various dielectric materials is also presented and the radiation patterns of a single slot are included