| 摘要 |
PROBLEM TO BE SOLVED: To obtain a desired filter by automatically switching from a superconducting filter that uses a superconducting thin film to a normal conducting filter that uses a normal conducting filter, when an operating temperature rises. SOLUTION: Circuit patterns 30 are formed between a pair of dielectric diaphragms 10 and 20 which are arranged oppositely, and a superconducting filter of a strip line structure is formed by forming ground planes 40 on outer planes of the diaphragms 10 and 20. The circuit pattern 30 consists of an inside that comprises a normal conducting thin film 32, and a peripheral part that comprises a superconducting thin film 31. Because current converges on the film 31 of the peripheral part and flows, when it is operated at a very low temperature, it functions as a superconducting filter. Since current converges on the film 32 in the inside and flows when an operation temperature rises, it automatically changes from the superconducting filter to a normal conducting filter and operates. |
