Local wave Green's functions of parallel plate metamaterial-based gap waveguides with one hard wall

The purpose of the presented paper is to give the derivation of the Green's functions of oversized waveguides with one hard wall. Two different realizations of the hard wall were considered: idealized PEC/PMC model and the corrugated hard surface. The applied analysis method avoids the complexity of the Floquet mode approach by using appropriate asymptotic boundary conditions for the observed periodic structure. This is possible because the period of the used periodic structures is very small compared to the wavelength. The developed Green's functions have poles corresponding to surface wave modes and waveguide modes, and their properties are determined by considering the pole distribution. We have also developed a program that calculates the electromagnetic field distribution inside the considered waveguides. The computed results are compared with the results obtained with the general electromagnetic solver, and the agreement is very good.