Substrate integrated waveguide (SIW) filter: design methodology and performance study

A high-performance substrate integrated waveguide (SIW) filter formed by top and bottom metal layers which embed a dielectric slab and two sidewalls of metallic vias is presented. Two different configurations (named as in-line and off-line) are proposed and two different design techniques are discussed: direct method and indirect method. In both cases modeled/simulated results are validated by means of measurements and good agreement is observed over the whole frequency range 0-110GHz. The indirect method allows the prediction of the stop bands with very small computational effort; therefore it is a very promising technique for design of SIW structures.