Power transmission behaviour of coplanar superconducting waveguides

The authors describe the complex behavior of superconducting coplanar waveguides of varying geometries under the influence of temperature and transmitted power. For this reason high power levels up to 35 dBm have been applied to characterize the saturation behavior of the waveguides at 18 GHz. At low temperatures the transmitted power is shown to drop drastically (about 30 dB) when the waveguide leaves the superconducting state. At higher temperatures a kind of saturation state can be observed. The transmitted power coefficient first remains high and then drops slowly with increasing incident power. The superconducting waveguide recovered reversibly from the state of saturation during the entire measurement. It is shown that it is possible to calculate the current-carrying capacity by using the ratio of the area of the current flow to the complete cross section.<>