Circuit and method for amplification of an electrical input signal

A method for amplifying an input signal comprising the steps of:

• dividing an input signal into a first partial signal and a second partial signal;
• amplifying said first partial signal and a first amplification stage and amplifying said second partial signal in a second amplification stage;
• recombining the amplified first partial signal and the amplified second partial signal;
• regulating amplification of the first amplification stage dependent on a current difference between a supply current requirement of the second amplification stage and a supply current requirement of the first amplification stage;
• and
• regulating amplification of the second amplification stage dependent on a current difference between the supply current requirement of the first amplification stage and the supply current requirement of the second amplification stage.

A magnetic resonance system comprising:

• a magnetic resonance scanner comprising a basic field magnet, a gradient coil system and a radio-frequency antenna system;
• a sequence controller connected to said magnetic resonance scanner that supplies a pulse sequence to said gradient coil system and to said radio-frequency antenna system to operate said magnetic resonance scanner to acquire magnetic resonance data from a subject therein;
• a source of radio-frequency signals;
• and
• an amplification circuit connected between said source of radio-frequency signals and said radio-frequency antenna system, said amplification circuit comprising a signal splitter supplied with an input signal that divides said input signal into a first partial signal and a second partial signal, a first signal path supplied with said first partial signal from said signal splitter, said first signal path comprising a first amplification stage that amplifies said first partial signal, a second signal path supplied with said second partial signal from said signal splitter, said second signal path comprising a second amplification stage that amplifies said second partial signal, a current supply that supplies current to each of said first and second signal amplification stages, a signal combiner connected downstream from said first and second amplification stages that re-combines the first and second partial signals, respectively amplified by said first and second amplification stages, to form an output signal, and a regulation device connected to each of said first amplification stage and said second amplification stage that regulates amplification of said first partial signal dependent on a current difference between a supply current requirement of the second amplification stage and a supply current requirement of the first amplification stage, and that regulates amplification of the second partial signal dependent on a difference between the supply current requirement of the first amplification stage and the supplied current requirement of the second amplification stage.