Abstract: Predistorting an input signal prior to amplification in an RF power amplifier (206) includes isolating a plurality sub-band signals, each representing a portion of the input signal s(t). The method includes independently modifying an amplitude and a phase of each of the plurality of sub-band signals. The modification of the amplitude and/or phase is performed using a set of signal weighting parameters (weights) w and W, controlling linear and nonlinear modifications respectively, which are determined in an adaptive process by an adaptive controller (224). After modification, each of the sub-bands are summed together to obtain a predistorted input signal for an RF power amplifier (206).

Abstract: Method (500) and system (402) for actively detecting and determining a range of a remotely located radio receiver (100). The invention also provides a method and system to determine whether a remote receiver (100) is receiving a transmitted signal (418) and the minimum necessary transmitter power required to establish a communication link to the receiver (100). Finally, the invention also provides a method and system to resolve directional ambiguities due to multipath.

Abstract: RF amplifier system (200) incorporating feedforward linearization. The system includes a digital waveform source (202) generating digital data s(t) representative of at least one analog signal. The system also includes a feedforward linearization circuit for reducing a distortion of an RF power amplifier (212). The feedforward linearization circuit includes a differential amplifier (230) arranged for generating an error signal. The error signal is determined based on a difference between the distorted RF output signal and an analog RF reference signal (229) generated from the digital data.

Abstract: RF amplifier system (200) incorporating feedforward linearization. The system includes a digital waveform source (202) generating digital data s(t) representative of at least one analog signal. The system also includes a feedforward linearization circuit for reducing a distortion of an RF power amplifier (212). The feedforward linearization circuit includes a differential amplifier (230) arranged for generating an error signal. The error signal is determined based on a difference between the distorted RF output signal and an analog RF reference signal (229) generated from the digital data.

Abstract: Predistorting an input signal prior to amplification in an RF power amplifier (206) includes isolating a plurality sub-band signals, each representing a portion of the input signal s(t). The method includes independently modifying an amplitude and a phase of each of the plurality of sub-band signals. The modification of the amplitude and/or phase is performed using a set of signal weighting parameters (weights) w and W, controlling linear and nonlinear modifications respectively, which are determined in an adaptive process by an adaptive controller (224). After modification, each of the sub-bands are summed together to obtain a predistorted input signal for an RF power amplifier (206).

Abstract: Method (500) and system (402) for actively detecting and determining a range of a remotely located radio receiver (100). The invention also provides a method and system to determine whether a remote receiver (100) is receiving a transmitted signal (418) and the minimum necessary transmitter power required to establish a communication link to the receiver (100). Finally, the invention also provides a method and system to resolve directional ambiguities due to multipath.