Effect of finite metallization thickness on radiation characteristics of a dielectric waveguide loaded with periodic strips

The spectral domain approach is extended to analyzing the radiation of millimeter waves from a dielectric waveguide periodically loaded with thick metallic strips. The formulation views the electric current sheets on the upper and lower surfaces, and inside the strips as the source quantities to be determined so that the original problem is modelled as a multilevel-thin-strips-loaded dielectric waveguide, which, in turn, may be analyzed by the spectral domain approach. The radiation characteristics are demonstrated as a function of the strip thickness. It is shown that there is a significant difference in the leakage constants of TE and TM mode excitations.