Coplanar waveguide

Coplanar waveguide is a type of electrical planar transmission line which can be fabricated using printed circuit board technology, and is used to convey microwave-frequency signals.

On a smaller scale, coplanar waveguide transmission lines are also built into monolithic microwave integrated circuits.

Coplanar waveguide was invented in 1969 by Cheng P. Wen, primarily as a means by which non-reciprocal components such as gyrators and isolators could be incorporated in planar transmission line circuits.

In consequence CPW will not support a true TEM wave; at non-zero frequencies, both the E and H fields will have longitudinal components (a hybrid mode).

[4] Coplanar waveguides play an important role in the field of solid state quantum computing, e.g. for the coupling of microwave photons to a superconducting qubit.

[13] Coplanar waveguide resonators have also been employed to characterize the material properties of (high-Tc) superconducting thin films.