Design of air-filled rectangular waveguide bandpass filters by DBFILTER code for terahertz applications

In this paper we describe the CAD of conventional air-filled rectangular waveguide E-plane filter structures for terahertz applications. The software package DBFILTER has been developed with the specific goal of eliminating all experimental characterizations and manual adjustments required in the final filters. The software package DBFILTER was used for filter synthesis and design and the one actual filter implementation is presented. The same code can be used for multilayer dielectric or air-filled metal-pipe on wafer rectangular waveguide bandpass filter structures on a GaAs or silicon substrates with minor modifications.