Comparison of surface mounted high quality filters for combination of substrate integrated and waveguide technology

A comparison of substrate integrated waveguide (SIW) and substrate mounted waveguide (SMW) filters with focus on the quality factor Q is presented. Two differently coupled K-band SMW filters are compared to stand-alone SIW and waveguide filters, all comprised of five resonators. The SIW and waveguide filters are directly coupled through H-plane discontinuities. The first SMW filter is coupled using an iris while the second one is coupled via a microstrip stub. They are simulated using numerical field solvers and compared to simulated and measured responses of a SIW prototype filter. This comparison shows a Q factor improvement of a factor 3.7 for the SMW filters over the SIW filters.