Simulation and optimization of post-wall waveguide based compact circuits for micro and millimeter waves

Functional post-wall waveguide (PWW) based passive circuits are formed by introducing specific arrangements of additional posts into the PWW structure. Each arrangement represents a circuit element and consists of a circular array of cylindrical posts periodically distributed on the circumference of the corresponding ring. The circular arrays (i.e. the circuit elements) provide enough degrees of freedom to tailor the spectral response in the framework of an ultra-compact planar filter topology. The PWW circuit is analyzed using image theory in combination with the lattice sums technique yielding a highly-efficient semi-analytical computational scheme that is perfectly suitable for the numerical structural optimization of mm-wave band-pass filters. Along an exemplary study we demonstrate the feasibility of steep skirt selectivity within a device footprint of around 0.75A
²
.