Patent ID: 7251293

Claim:
A method for reducing spurious emissions in an amplified signal by applying pre-distortion, whose magnitude is frequency-dependent, to an input signal to generate a pre-distorted signal, such that, when the pre-distorted signal is applied to an amplifier to generate the amplified signal, the pre-distortion reduces the spurious emissions in the amplified signal, wherein the pre-distorted signal is generated by: (a) generating a first frequency-dependent pre-distortion signal corresponding to a first set of frequency components for the input signal; (b) generating a second frequency-dependent pre-distortion signal corresponding to a second set of frequency components for the input signal, wherein the first set of frequency components is different from the second set of frequency components; and (c) combining the first and second frequency-dependent pre-distortion signals to generate the pre-distorted signal, wherein: the first set of frequency components corresponds to positive-frequency components of the input signal, wherein the positive-frequency components correspond to frequencies that are greater than a center frequency of the input signal; and the second set of frequency components corresponds to negative-frequency components of the input signal, wherein the negative-frequency components correspond to frequencies that are smaller than the center frequency of the input signal.