Design and simulation of 94 GHz metal PBG waveguide

The design and simulation of 94 GHz metal PBG cylindrical waveguide with a wraparound co-axial coupler has been presented. A WR-8 rectangular waveguide drives a combined wraparound co-axial / MPBG cylindrical waveguide system. The wraparound co-axial input coupler converts a dominant TE₁₀ rectangular waveguide mode into a TE₄₁₁ resonator mode and which is then coupled into the MPBG waveguide for the desired TE₀₁ circular mode. The designed structure has been cold analyzed with the 3-D electromagnetic CST Microwave studio code. The Eigen mode analysis ensures that how the RF magnetic field couples the co-axial waveguide through four azimuthally spaced apertures. Further, this analysis shows the confinement of the desired TE₀₁-like mode only in the defect portion of the PBG triangular lattice structure and all other competing spurious modes have been suppressed. The transient analysis confirms good propagation and mode selectivity of PBG waveguide through the calculation of insertion loss. The coupler offers a return loss and insertion loss of -20 dB and -0.5 dB respectively with a wide bandwidth about ~6%.