Abstract: Systems and methods are provided for providing a hybrid signal having a reduced crest factor. A digital signal is generated that assumes one of a plurality of vector states at discrete sampling times, with each of the plurality of vector states having an associated phase. An analog signal is monitored to determine when a phase of the analog signal is aligned with the phase of a vector state assumed by the digital signal. A crest factor reduction is applied to the digital signal if the digital signal assumes a vector state having an associated phase aligned with the phase of the analog signal to provide a compressed digital signal. The compressed digital signal and the analog signal are combined to provide the hybrid signal. The analog signal is not altered prior to being combined with the compressed digital signal.

Abstract: Systems and methods are provided for generating dual outputs in a digital exciter system. A first signal path produces one of a frequency modulated audio signal, a digital information signal, and a signal comprising both frequency modulated audio and digital information. A second signal path produces one of a frequency modulated audio signal, a digital information signal, and a signal comprising both frequency modulated audio and digital information. A main exciter output provides one of the signal produced at the first signal path and the signal produced at the second signal path to an associated first signal destination. An auxiliary exciter output provides one of the signal produced at the first signal path and the signal produced at the auxiliary signal path to an associated second signal destination.

Abstract: Systems and methods are provided for providing a hybrid signal having a reduced crest factor. A digital signal is generated that assumes one of a plurality of vector states at discrete sampling times, with each of the plurality of vector states having an associated phase. An analog signal is monitored to determine when a phase of the analog signal is aligned with the phase of a vector state assumed by the digital signal. A crest factor reduction is applied to the digital signal if the digital signal assumes a vector state having an associated phase aligned with the phase of the analog signal to provide a compressed digital signal. The compressed digital signal and the analog signal are combined to provide the hybrid signal. The analog signal is not altered prior to being combined with the compressed digital signal.

Abstract: Systems and methods are provided for amplifying a composite input signal, comprising a drive signal and an envelope signal, at a power amplifier. A secondary modulation, representing a portion of the composite input signal falling outside of a frequency band associated with the envelope signal, is produced for the drive signal. The secondary modulation is applied to the drive signal. The drive signal is amplified at the power amplifier to produce an amplified signal. At least a portion of the envelope signal is employed to drive a supply terminal of the power amplifier.

Abstract: Systems and methods are provided for efficient amplification of a signal utilizing a modified Doherty amplifier system. A modified Doherty amplifier system includes a nonlinear main amplifier and a nonlinear auxiliary amplifier. An impedance-inverting network separates the main amplifier from an associated load. A second quarter wave transmission line separates the auxiliary amplifier from an associated signal source. The signal source has an associated minimum signal power, such that the signal power never drops below a predetermined percentage of a peak signal power.