On the Analysis and Design of Spurline Bandstop Filters

The parameters of general two-coupled lines and symmetric three-coupled lines in an inhomogeneous medium for the lossless case are obtained. The impedance and chain matrices of spurline bandstop filters are derived. One-section spurline bandstop filters with their stopbands centered near 33 GHz have been designed and tested. There is excellent agreement between the experimental results and those predicted theoretically.