The RF coil or the RF probe for the switching circuit for the RF circuit and the high frequency signal sending and receiving electronic switch and the magnetic resonance imaging device for the magnetic resonance imaging device, in the switching circuit for

摘要

PPROBLEM TO BE SOLVED: To provide a switching circuit for an RF circuit of an MRI apparatus capable of blocking large high frequency current passing when conducting a diode and improving isolation when not conducting it. PSOLUTION: A transmission circuit 5 is connected through a diode D2 and a capacitor C4 to a transmission/reception coil 7, and a reception circuit 9 and a protective circuit 8 are connected to the transmission/reception coil 7. D0 and D1 are serially connected at polarities opposite to each other between a transmission line and the ground and C0 is inserted between the diodes D0 and D1. A bias power source 6 for controlling the switching of the D2 is connected holding the D2 there between and a bias power source 1 is connected holding the D0 and C0 there between. A low-pass filter circuit 2 is connected holding the C0 and D1 there between. Control is performed so as to conduct the bias current of the D2 and not to conduct the bias current of the D0 and D1 for the time of transmission, and so as not to conduct the bias current of the D2 and to conduct the bias current of the D0 and D1 for the time of reception. PCOPYRIGHT: (C)2008,JPO&INPIT