高温酸化物超電導薄膜スイッチを用いたミリ波パルス源の検討

抄録

The characteristics of switching of millimeter wave energy are theoretically considered using a simple model of a YBa₂Cu₃O_7-x superconducting film. In the superconducting state, the transmission of electromagnetic wave through a superconducting film is determined by the London penetration depth. While, in the normal conducting state, it is determined by the classical skin depth, which is larger than the London penetration depth. Thus, the superconducting films may be applicable to microwave or millimeter wave switching. If the transition from superconducting to normal conducting state of the film, which is installed in a millimeter wave cavity, is performed at high speed, the energy stored in the cavity may be released to the output circuit as a pulse. The transmission coefficients of the YBa₂Cu₃O_7-x film are calculated and the output powers from a millimeter wave cavity are numerically analyzed. The peak output powers depend on the film thickness as well as on the unloaded quality factor of the cavity.