Radio frequency amplifying device and magnetic resonance imaging apparatus

A magnetic resonance imaging apparatus comprising a radio frequency amplifying device and a Radio Frequency (RF) coil, wherein

• the radio frequency amplifying device includes:
• load impedance calculating circuitry configured to calculate a load impedance on a basis of information about a voltage standing wave rate and a phase on an output side of radio frequency amplifying circuitry;
• and
• controlling circuitry configured to adjust a gain and a phase of a signal to be input to the radio frequency amplifying circuitry, in accordance with the load impedance calculated by the load impedance calculating circuitry, and
• the RF coil generates a radio frequency magnetic field on a basis of an output signal output from the radio frequency amplifying device.