Linear propagation characteristics of periodically segmented waveguides.

Periodically segmented planar waveguides are modeled by using the rigorous modal method of diffraction gratings. The radiation loss, effective index, and electric-field strength distribution are analyzed for different segment duty cycles. It is shown that except for the low radiation loss and possible presence of stop bands, a segmented waveguide behaves much like a uniform waveguide. The theoretical calculation confirms the low radiation loss observed experimentally.