Abstract: An amplification system includes a differential output circuit that provides an amplified output to drive a load. A main amplifier is coupled to a terminal of the differential output circuit via a main path, corresponding to a transmission line. A peak amplifier is coupled to another terminal of the differential output circuit via a peak path, corresponding to a transmission line. In a single-ended mode while the peak amplifier is deactivated for amplification purposes, the peak path performs an impedance inversion to effectively ground the other terminal of the differential output circuit. In a differential mode, each of the peak amplifier and the main amplifier operates to conduct current to respective terminals of the differential output circuit and each of the main path and the peak path provides a predetermined output impedance to the differential output circuit.

Abstract: An amplification system includes a differential output circuit that provides an amplified output to drive a load. A main amplifier is coupled to a terminal of the differential output circuit via a main path, corresponding to a transmission line. A peak amplifier is coupled to another terminal of the differential output circuit via a peak path, corresponding to a transmission line. In a single-ended mode while the peak amplifier is deactivated for amplification purposes, the peak path performs an impedance inversion to effectively ground the other terminal of the differential output circuit. In a differential mode, each of the peak amplifier and the main amplifier operates to conduct current to respective terminals of the differential output circuit and each of the main path and the peak path provides a predetermined output impedance to the differential output circuit.

Abstract: A broadband high efficiency (RF) radio frequency amplifier architecture is disclosed. Systems and methods are provided for generating an amplified radio frequency (RF) signal representing a baseband input signal. First, second, and third signal paths are configured to amplify first, second, and third intermediate signals to provide respective amplified signals. A signal combiner assembly is configured to combine the amplified signals to produce the compound amplified RF signal. The signals are combined such that a first amplified signal modulates a load impedance at respective outputs of an active device associated with the plurality of amplifiers in the second signal path, and one of the first amplified signal, the second amplified signal, and a sum of the first and second amplified signals modulates a load impedance of an active device associated with the plurality of amplifiers in the third signal path.

Abstract: A broadband high efficiency (RF) radio frequency amplifier architecture is disclosed. Systems and methods are provided for generating an amplified radio frequency (RF) signal representing a baseband input signal. First, second, and third signal paths are configured to amplify first, second, and third intermediate signals to provide respective amplified signals. A signal combiner assembly is configured to combine the amplified signals to produce the compound amplified RF signal. The signals are combined such that a first amplified signal modulates a load impedance at respective outputs of an active device associated with the plurality of amplifiers in the second signal path, and one of the first amplified signal, the second amplified signal, and a sum of the first and second amplified signals modulates a load impedance of an active device associated with the plurality of amplifiers in the third signal path.

Abstract: Systems and methods are provided for generating a modulated radio frequency (RF) output signal representing a baseband input signal. A digitizer is configured to sample the baseband input signal and produce an N-bit binary digital signal representing a scaled linear function of the signal amplitude. An RF signal source configured to produce an RF carrier signal. N amplifier paths each include at least one amplifier configured to receive the RF carrier signal as an input and provide a corresponding output RF signal. The amplifiers associated with each of the N amplifier paths are active only when a corresponding bit of the digital signal assumes a first value. A power combiner assembly is configured to combine the outputs of the plurality of amplifier paths to deliver the modulated RF output signal.

Abstract: Systems and methods are provided for generating a modulated radio frequency (RF) output signal representing a baseband input signal. A digitizer is configured to sample the baseband input signal and produce an N-bit binary digital signal representing a scaled linear function of the signal amplitude. An RF signal source configured to produce an RF carrier signal. N amplifier paths each include at least one amplifier configured to receive the RF carrier signal as an input and provide a corresponding output RF signal. The amplifiers associated with each of the N amplifier paths are active only when a corresponding bit of the digital signal assumes a first value. A power combiner assembly is configured to combine the outputs of the plurality of amplifier paths to deliver the modulated RF output signal.

Abstract: Systems and methods are provided for producing an amplified radio frequency (RF) signal representing a baseband input signal. A first amplifier amplifies a first intermediate signal to provide a first amplified signal. Second and third amplifiers amplify a second intermediate signal to provide second and third amplified signals. A signal combiner combines the first, second, and third amplified signals to produce the amplified RF signal. An RF modulator modulates an RF carrier signal with a baseband input signal to provide the first and second intermediate signals. The RF modulator provides the first and second intermediate signals such that the first amplified signal is out-of-phase with each of the second and third amplified signals at an output of an active device within the second amplifier when the amplitude of the baseband input signal exceeds a threshold voltage and in phase when the baseband input signal is below a threshold voltage.

Abstract: A circuit for amplifying an input signal can comprise a plurality of couplers. A splitting coupler of the plurality of couplers can receive the input signal and a combining coupler of the plurality of couplers can provides an output signal. N number of amplifiers can be included in the circuit to amplify the input signal, wherein N is a non-binary integer greater than one. At least one of the plurality of couplers can comprise a hybrid coupler that has two ports terminated into substantially equal reactances.

Abstract: Systems and methods are provided for modulating a radio frequency (RF) carrier signal with a baseband input signal and amplifying the modulated RF carrier signal to provide an amplified RF signal. A quadrature combiner is configured to provide the amplified RF signal at an associated output port. A main amplifier is configured to receive a first modulated RF signal and provide a main output to one of a through port and a coupled port of the quadrature combiner. An auxiliary amplifier is configured to receive a second modulated RF signal and provide an auxiliary output to an isolation port of the quadrature combiner.

Abstract: An amplification system is provided that comprises a push-pull amplifier system having a first power transistor series coupled with a second power transistor that alternately switch between a push-pull amplifier mode of operation and a single-ended amplifier mode of operation. In the push-pull amplifier mode, both the first power transistor and the second power transistor alternately conduct to provide an amplified output signal to an output load in response to an input signal having an amplitude that is greater than or equal to a threshold level. In the single-ended amplifier mode of operation, the first power transistor conducts and the second power transistor is disabled for amplification purposes in response to the input signal having an amplitude that is less than the threshold level.

Abstract: An amplification system is provided that comprises a push-pull amplifier system having a first power transistor series coupled with a second power transistor that alternately switch between a push-pull amplifier mode of operation and a single-ended amplifier mode of operation. In the push-pull amplifier mode, both the first power transistor and the second power transistor alternately conduct to provide an amplified output signal to an output load in response to an input signal having an amplitude that is greater than or equal to a threshold level. In the single-ended amplifier mode of operation, the first power transistor conducts and the second power transistor is disabled for amplification purposes in response to the input signal having an amplitude that is less than the threshold level.

Abstract: A system for amplifying an input signal can comprise a main amplifier to amplify a delayed version of the input signal. The system can also comprise a peak amplifier to amplify the input signal upon the input signal reaching a threshold level and disable amplification upon the input signal falling below the threshold level. The system can further comprise a voltage combiner to electromagnetically couple the output of the main amplifier and the peak amplifier, such that an output impedance at an output node of the voltage combiner is a high impedance if the input signal is below the threshold level.

Abstract: Systems and methods are provided for producing an amplified radio frequency (RF) signal representing a baseband input signal. A first amplifier amplifies a first intermediate signal to provide a first amplified signal. Second and third amplifiers amplify a second intermediate signal to provide second and third amplified signals. A signal combiner combines the first, second, and third amplified signals to produce the amplified RF signal. An RF modulator modulates an RF carrier signal with a baseband input signal to provide the first and second intermediate signals. The RF modulator provides the first and second intermediate signals such that the first amplified signal is out-of-phase with each of the second and third amplified signals at an output of an active device within the second amplifier when the amplitude of the baseband input signal exceeds a threshold voltage and in phase when the baseband input signal is below a threshold voltage.

Abstract: Systems and methods are provided for modulating a radio frequency (RF) carrier signal with a baseband input signal and amplifying the modulated RF carrier signal to provide an amplified RF signal. A quadrature combiner is configured to provide the amplified RF signal at an associated output port. A main amplifier is configured to receive a first modulated RF signal and provide a main output to one of a through port and a coupled port of the quadrature combiner. An auxiliary amplifier is configured to receive a second modulated RF signal and provide an auxiliary output to an isolation port of the quadrature combiner.

Abstract: A circuit for amplifying an input signal can comprise a plurality of couplers. A splitting coupler of the plurality of couplers can receive the input signal and a combining coupler of the plurality of couplers can provides an output signal. N number of amplifiers can be included in the circuit to amplify the input signal, wherein N is a non-binary integer greater than one. At least one of the plurality of couplers can comprise a hybrid coupler that has two ports terminated into substantially equal reactances.

Abstract: A system for amplifying an input signal can comprise a main amplifier to amplify a delayed version of the input signal. The system can also comprise a peak amplifier to amplify the input signal upon the input signal reaching a threshold level and disable amplification upon the input signal falling below the threshold level. The system can further comprise a voltage combiner to electromagnetically couple the output of the main amplifier and the peak amplifier, such that an output impedance at an output node of the voltage combiner is a high impedance if the input signal is below the threshold level.

Abstract: A tunable impedance inverter is presented for a Doherty amplifier circuit having first and second amplifiers connected in parallel between an input circuit for receiving an input signal and an output circuit for supplying an output signal to a load. An impedance inverter is coupled between the first amplifier and the output circuit. The inverter has an input and an output and a tunable mechanical strip line of variable electrical length interposed between the input and the output. An adjuster adjusts the electrical length of the strip line. The adjuster adjustably varies the electrical length of said pathway to thereby adjust the center frequency of said output 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: Apparatus and method are presented for broadcasting an RF signal comprised of analog FM and digital signals. An analog FM source provides an analog FM signal. A digital source provides a digital signal. A splitter splits the FM signal into a fractional portion and remainder portion. A summer combines the fractional portion with the digital signal to provide a first combined signal. A main FM transmitter amplifies the remainder portion to provide an amplified FM signal. A digital transmitter amplifies the first combined signal to provide an amplified combined signal. A combiner combines the amplified FM signal and the amplified combined signal to provide a composite RF signal to be broadcasted.

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.