Investigation of behaviour of the electromagnetic waves in a parallel plate waveguide with grid type surfaces

In this study, the behavior of the electromagnetic waves inside and outside of a strip grating parallel plate waveguide is investigated by using ray tracing method. First of all, reflection and transmission at a grid type interface are examined between two simple media. The reflection and transmission coefficients for this interface are obtained by using approximate boundary conditions. With the usage of these coefficients, the effects of waves that are excited outside for TE and TM modes are inspected in both mediums and compared with the results of the field expressions by Floquet mode. Afterwards, the reason of preference of strip grating parallel plate waveguides instead of the conventional parallel plate waveguides is mentioned such that while strip's width increases, dissipated loss also increases. However, smaller selection of the strip's width increases the amount of the expelled wave. Thus, it is shown that the optimization of strip's width is necessary.