Dispersive characteristics of a waveguide with periodic impedance of walls

The present article is devoted to some problems of implementation of concept of a periodic impedance of walls in the process of studying wave propagation in waveguides. It enables to approach the calculation of different waveguide devices from the unified position. The implementation of such approach is shown on an example of absorbing filter of harmonics representing a sequently located round holes in a narrow or wide wall. It is shown that such tasks can be solved as Helmholtz equation with impedance boundary conditions for tangent components of electric and magnetic fields on the wall's surface.