A coplanar waveguide (CPW) apparatus comprises a substrate having a first surface and an opposing second surface. The substrate comprises a metal layer proximate to the first surface. The metal layer comprises a conductive trace comprising a signal line coupled to a launcher element at a first end of the signal line, and a ground plane co-planar with the conductive trace. The ground plane defines a substantially rectangular first region surrounding the launcher element and defining a second region surrounding the signal line, the first and second regions substantially devoid of conductive material. The launcher element has a substantially rectangular shape with a width greater than a width of the signal line at the first end.