A wireless RF coil unit according to the embodiment includes at least one receiver, a converter, a mixer and a filter. The at least one receiver receive a first analog signal having a first frequency synchronized with a first clock of a device different from the coil unit, and a second analog signal having a second frequency different from the first frequency. The converter converts the first analog signal into a first digital signal, and the second analog signal into a second digital signal, in accordance with a second clock of the coil unit. The mixer generates a multiplication signal of the first digital signal and the second digital signal. The filter passes a predetermined frequency component in the multiplication signal and outputs an intermediated frequency signal.