Lumped-Element Coplanar-Waveguide Diplexer

Novel reduced-size lumped-element coplanar-waveguide (CPW) diplexer is proposed, using planar lumped-elements to realize the 3rd order low-pass and band-pass filters in the diplexer structure. Simple equivalent-circuit model is also established, from which the passband behavior of the lumped-element diplexer structure may be characterized. Specifically, a CPW diplexer that is target for mixer applications to separate the IF/LO signals is established and carefully examined.