Transmission line approximation for periodic structures of dielectric bodies and its application to absorber design

The field quantities associated with a periodic structure can be written as a plane wave modulated by periodic vector functions. The combination of a formulation in terms of the averaged periodic functions and an effective material concept leads to a transmission line approximation (TLA). This method greatly simplifies the solution for scattering from periodic structures such as a microwave absorber and is useful for design purposes. The accuracy and limitations of TLA will be examined by comparison with the periodic moment method (PMM) for various design examples.