Abstract :
A new type of sharp, high-rejection wideband microstrip filter based on signal-interference techniques is reported. The proposed topology uses, for the first time, rat-race couplers operating as transversal filtering sections (TFSs). Design equations and guidelines for this TFS are provided. Furthermore, to prove its experimental usefulness, a 6.5 GHz ultra-wideband prototype has been synthesised, constructed and measured
