Numerical analysis of a metamaterial-based ridge gap waveguide with a bed of nails as parallel-plate mode killer

This paper presents a numerical analysis of a ridge gap waveguide. Ridge gap waveguides belongs to a new metamaterial-based waveguide technology for millimeter and submillimeter waves which emerged recently. The magnetic boundary condition or high-impedance surface (ideally a PMC) has been realized by means of a bed of nails as parallel-plate mode killer. Field plots of the ideal PEC-over-PMC ridge gap waveguide are presented, as well as when the PMC is realized by the bed of nails. The quasi-TEM mode shows an octave useable bandwidth for the bed of nails case.