Accurate consideration of metal losses in planar waveguide junctions using an efficient integral equation technique

Metal losses in passive waveguide devices are more pronounced and hazardous at higher frequencies. In this paper, we propose a very efficient integral equation technique for the accurate consideration of losses in the metal walls of any planar waveguide junction. For verification purposes, the results provided by the novel theory are successfully compared with those obtained with a lower efficiency commercial software. Combining this novel technique with a perturbation method that includes propagation losses, we have been able to predict all the losses effects in a 4-pole coupled cavities filter.