| 摘要 |
PROBLEM TO BE SOLVED: To prevent a balun (a balanced to unbalanced transformer) from heat generation by electric current transmissions from high-frequency magnetic fields. SOLUTION: A coaxial cable 65 transmits the MR signals that are radiated from a subject as an electromagnetic signal and converted into an electric signal by an element coil. A balun 67 is installed on the coaxial cable 65. The balun 67 includes an inner cylinder 67a through which the coaxial cable 65 is inserted, an outer cylinder 67b arranged outside the inner cylinder 67a in the state that they are electrically insulated from each other, a trap tuning condenser 67e with its both ends connected with the inner and outer cylinders 67a and 67b respectively, and cross diodes (diodes 67f, 67g) connected in parallel with the trap tuning condenser 67e for invalidating the trap tuning condenser 67e when high-frequency signals are transmitted. COPYRIGHT: (C)2010,JPO&INPIT |
