Feedforward amplifier

A feedforward amplifier for use with an input signal comprising:

• a first feedforward circuit and a second feedforward circuit;
• a) said first feedforward circuit comprising
• a first distortion detection circuit and a first distortion cancellation circuit operating at a first frequency, said first distortion detection circuit having a first input port and detecting distortion in the output of a main amplifier, said first distortion cancellation circuit canceling the detected distortion by amplifying the detected distortion by a first auxiliary amplifier and inserting the amplified detected distortion into the output of said main amplifier;
• b) said second feedforward circuit comprising
• a second distortion detection circuit and a second distortion cancellation circuit operating at a second frequency,
• a power combiner included commonly with said second distortion detection circuit and said second distortion cancellation circuit,
• said second distortion detection circuit comprising
• second input port,
• said first feedforward circuit having an output coupled to an input of said power combiner, said second distortion detection circuit detecting distortion in the output of said first feedforward circuit, said second distortion cancellation circuit canceling the detected distortion by amplifying the detected distortion by a second auxiliary amplifier and inserting the amplified detected distortion into the output of said first feedforward circuit,
• wherein said input signal is input to said second input port,
• an output of said second distortion detection circuit coupled to said first input port of said first distortion detection circuit and providing a portion of said input signal to said first distortion detection circuit, and
• said first frequency and said second frequency are different from each other.