Patent ID: 6424215
Filing Date: 2002-07-23
Classification: H03F

Abstract:
A feedforward (FF) RF amplifier comprising:a RF signal input and a RF signal output; a first amplification path including a first RF amplifier and a second amplification path including a second RF amplifier; the first and second RF amplifiers being substantially identical; the first and second amplification path each disposed between the RF signal input and the RF signal output and each amplification path adding directly to the RF signal output; an intermodulation distortion (IMD) adjusting path disposed between an input to the first RF amplifier and an input to the second RF amplifier; including first and second IMD adjusting circuitry; a signal coupling path coupling an output of the first RF amplifier to a node of the IMD adjusting path located intermediate the first and second IMD adjusting circuitry; the signal coupling path providing the IMD for processing by the second IMD adjusting circuitry; the combined effect of the IMD adjusting path and signal coupling path providing inverted distortion terms at an input to the second RF amplifier; and circuit delays for adjusting the signals in the first and second amplification paths and the IMD adjusting path so that the multi-tones are maintained in alignment at an input to the first RF amplifier and at an input to the second RF amplifier and at the RF signal output and input nodes for applying spreading codes to outputs of the first and second RF amplifiers; and despreading circuitry connected to the RF signal output for minimizing a despread tone output.