Parasitic High Q-Factor Open-Box Modes With 3-D Printed Dielectric-Filled Metal Waveguides

High Q-factor open-box mode resonances have been found in the microwave measurements of several 3-D printed dielectric-filled metal-pipe rectangular waveguides (MPRWGs). These parasitic Fabry-Perot eigenmodes are confined by conductive walls transverse plane MPRWG and partially air-dielectric dielectric-air boundaries longitudinal direction. The excitation modes was previously speculated to be due inhomogeneous and/or anisotropic nature dielectric-fillers. This has now confirmed, representing woodpile-like dielectric structure (physical realm), with an constant tensor (simulation realm). Analytical numerical eigenmode solvers, used authors MPRWGs, applied here parallel-plate (PPWGs) circular (CWGs); identifying all individual modes. With former, its TM11 exhibits ultra-high approximately 2,300 at X-band, which is considerably higher than those other waveguide structures. Finally, a full-wave frequency-domain simulator that employs introduced this paper. new modeling technique independently confirms excited MPRWG, PPWG CWG paper provides foundations for accurately associated inhomogeneities anisotropy components; not just metal-walled structures considered here, but methodology could also extended generic substrate-based transmission lines.