This disclosure provides systems, methods and apparatus for a compact 3-D coplanar transmission line (CTL). In one aspect, the CTL has a proximal end and a distal end separated, in a first plane, by a distance D, the first plane being parallel to a layout area of a substrate. The plane is defined by mutually orthogonal axes x and z The CTL provides a conductive path having pathlength L. D is substantially aligned along axis z, L is at least 1.5×D, and the CPW is configured such that at least one third of the pathlength L is disposed along one or more directions having a substantial component orthogonal to the first plane. Less than one third of the pathlength L is disposed in a direction having a substantial component parallel to axis x.