Rectangular Microwaveguide with High-Tc Superconducting Wall

The peculiarities of electrodynamic properties of metal waveguide of extremely small height (microwaveguide) have found in experiments. They show dependence of phase velocity or wavelength in waveguide on attenuation in waveguide caused by both finite surface impedance of walls and a height of waveguide. These effects are displayed even at small values of surface impedance Z
_s
. Extremely-small-height waveguides are of interest for microwave technique, because their properties depend on impedance properties of wall material. Such a suitable material is high-Tc superconductors, impedance properties of which can be controlled by external factors, e.g. temperature, dc magnetic field or current, microwave or laser irradiation.