Patent ID: 7615999

Claim:
Circuit arrangement for operating a multi-channel transmit/receive antenna device or RF coil arrangement, with a number n of RF coils and/or coil segments, for use in a magnetic resonance imaging system, comprising directional couplers, characterized in: a number n of RF amplifiers or a multi-channel RF amplifier having n channels, for amplifying transmit signals to be fed to the number n of channels of the multi-channel transmit/receive antenna device or of RF coils and/or coil segments of the RF coil arrangement, respectively; a number n of circulators which are each connected with their first and second terminal into the RF path of each channel between the output of the RF amplifier and one of the channels of the multi-channel transmit/receive antenna device or RF coil arrangement, respectively; a number n of RF loads which arc each connected with the third terminal of the circulator of each channel and which are provided for dissipating RF power which is reflected into the second terminal of the related circulator; a number n of first directional couplers which are each connected between the output of the RF amplifier and the first terminal of the circulator and wherein the first directional couplers provide a first forward power signal and a first reflected power signal to an internal power monitoring unit of the RF amplifier and/or to a central power monitoring unit of the circuit arrangement.