Digitally controllable nonlinear pre-equalizer

A digitally controllable nonlinear pre-equalizer circuit receiving an input signal and generating an output signal, the circuit comprising:

• a splitter for dividing the input signal into a first signal path and a second signal path;
• an attenuator and a time delay element in the first signal path, the attenuator and the time delay element operable to generate a linear signal;
• a mixer and a vector modulator in the second signal path, the mixer being responsive to a signal from a digital to analog converter coupled to a processor chip providing a digital signal to the digital to analog converter, the processor chip being operable to store a plurality of power amplifier parameters corresponding to a plurality of power amplifiers, each power amplifier parameter being provideable as the digital signal, the mixer and vector modulator operable to generate a nonlinear signal;
• and
• a summer for summing the linear signal and the nonlinear signal to generate the output signal.

An amplifier system receiving an input signal and generating an output signal comprising:

• a power amplifier;
• a splitter for dividing the input signal into a first signal path and a second signal path;
• an attenuator and a time delay element in the first signal path, the attenuator and the time delay element operable to generate a linear signal;
• a mixer and a vector modulator in the second signal path, the mixer being responsive to a signal from a digital to analog converter coupled to a processor chip providing a digital signal to the digital to analog converter, the mixer and vector modulator operable to generate a nonlinear signal;
• and
• a summer for summing the linear signal and the nonlinear signal to generate a gain expansion signal, the gain expansion signal being input to the power amplifier, the power amplifier providing the output signal.

A satellite system receiving an input signal and generating an output signal comprising:

• a satellite;
• a power amplifier disposed on said satellite;
• a nonlinear pre-equalizer circuit coupled to said power amplifier, said nonlinear pre-equalizer circuit including,
• a splitter for dividing the input signal into a first signal path and a second signal path;
• an attenuator and a time delay element in the first signal path, the attenuator and the time delay element operable to generate a linear signal;
• a mixer and a vector modulator in the second signal path, the mixer being responsive to a signal from a digital to analog converter coupled to a processor chip providing a digital signal to the digital to analog converter,
• a summer for summing the linear signal and the nonlinear signal to generate a gain expansion signal, the gain expansion signal being input to the power amplifier, the power amplifier providing the output signal.

A method of digitally controlling a nonlinear pre-equalizer circuit receiving an input signal and generating an output signal, the method comprising:

• dividing the input signal into a first signal path and a second signal path;
• generating a linear signal by attenuating and time delaying the divided input signal in the first signal path;
• generating a nonlinear signal by mixing and phase shifting the divided input signal in the second signal path, the mixing being responsive to a signal provided by a digital to analog converter coupled to a processor chip;
• and
• summing the linear signal and the nonlinear signal to generate the output signal.