Microwave seminar | 26 September 2024

The paper considers surfaces with nonlocal impedance boundary conditions (NIBCs) typical for nontransparent surfaces with spatial dispersion of impedance (nonlocal surfaces). A contradiction arises when NIBCs are used, namely, violation of the orthogonality of eigenwaves in waveguides with NIBCs. Using the concept of far and local fields of a surface with NIBCs and the active power theorem, as well as the Lorentz lemma, expressions are obtained for the active power and the Lorentz form of the local field. Considering the quadratic forms of the local field is shown to eliminate the above contradiction and provide the orthogonality of eigenwaves in waveguides with NIBCs. The possibility of heuristic correction of the field in structures with quadratic NIBCs is discussed.