MRI DEVICE HIGH FREQUENCY PULSE GENERATING CIRCUIT AND HIGH FREQUENCY PULSE GENERATING METHOD USED THEREWITH

摘要

PURPOSE:To obtain a good picture image with a bad influence reduced due to a drift by an amplifier by providing an AC amplifier, which amplifies a variable pulse, and a DC impeding coupling capacitor connected to an after stage of the AC amplifier. CONSTITUTION:This high frequency pulse generator circuit 21 has AC amplifiers 27, 28 and DC blocking coupling capacitors 12, 13 connected between these amplifiers 27, 28 and a before described arithmetic part 6. A pulse P22 is oscillated by the second oscillator 3 by a frequency, in which an offset frequency omega' is added and deviated to a variable frequency omega1 of low frequency region including zero, and distributed by the second distributor 5 to obtain pulses P25, P26 with a phase pi/2 different. The pulses P25, P26 are amplified by the AC amplifiers 27, 28 and input to the arimetic part 6 by removing a gradually changing output drift component of the AC amplifiers 27, 28 by the DC blocking coupling capacitors 12, 13. Thus by educing a bad influence of a drift due to the amplifier, a good picture image can be obtained.