Novel lumped-element coplanar waveguide-to-slotline transitions

Novel reduced-size lumped-element coplanar waveguide-to-slotline transitions are proposed, using planar parallel LC circuits to replace the /spl lambda//4 transformer structure. A simple equivalent-circuit model is also established, from which various lumped-element transition structures are carefully examined. Specifically, a "ring-type L" lumped element transition with a 1.8:1 bandwidth and 1/12 the size of conventional ones is achieved.