Tuning properties of irregular posts in waveguide junctions - tunable filter application

In this paper the authors´ hybrid method of electromagnetic wave scattering is applied to investigate the tuning properties of rectangular posts in waveguide junctions. As an example a basic waveguide filters employing several conducting cylindrical posts with rectangular cross section are considered. The size and location of the posts in a waveguide junction are optimized to obtain the required frequency response characteristic of the structures. Since, the posts are inhomogeneous, they can be used as tuning elements. In this work it is shown, that a simple rotation of rectangular posts allows one to correct any inaccuracies created during fabrication of the filter structure. A good agreement is obtained between the results of this method and own measurements of the fabricated structure.