Metal Strip Grating on Grounded Dielectric Slab and PEC/PMC Shielded Interconnect: Modal Relationships.

This paper employs the spectral domain approach for full wave analysis of metal strip grating on grounded dielectric slab and microstrips shielded with either Perfect Electric Conductor (PEC) or Perfect Magnetic Conductor (PMC) walls. The modal relations between these structures are revealed by exploring their symmetries. It is derived analytically and validated numerically that all the even and odd modes of the latter two (when they are mirror symmetric) find their correspondence in the modes of metal strip grating on grounded dielectric slab when the phase shift between adjacent two unit cells is 0 or n. Extension to non-symmetric case is also made. Several factors, including frequency, grating period, slab thickness and strip width, are further investigated for their impacts on the effective permittivity of the dominant mode of PEC/PMC shielded microstrips. It is found that the PMC shielded microstrip generally has a larger wave number than the PEC shielded microstrip. [ABSTRACT FROM AUTHOR]