Abstract: In an embodiment, a method of generating a pulse-width modulated signal from an input signal includes calculating a finite number of basis functions of a first pulse-width modulated signal based on the input signal, and forming an electronic output based on the calculated finite number of basis functions.

Abstract: In accordance with an embodiment, a system includes a first amplifier and a first bandpass filter having an input coupled in series with an output of the first amplifier, and an output configured to be coupled to a load. The bandpass filter has a lower input impedance at an in-band center frequency than at out-of-band frequencies, and the first amplifier is configured to receive a pulse width modulated waveform filtered according to a first transfer function that attenuates sidebands of the pulse width modulated waveform.

Abstract: In one embodiment, a circuit comprises an adaptive predistorter and a nonlinear element coupled to an output of the predistorter. The predistorter is operative to predistort an input signal according to predistortion control parameters at a given sampling rate. The circuit further comprises an identification unit and a translation unit. The identification unit identifies nonlinearity parameters representing the nonlinearity of the nonlinear element by sampling the output of the nonlinear element at an identification sampling rate lower than twice a bandwidth at the output of the nonlinear element. The translation unit translates the identified nonlinearity parameters into the predistortion control parameters. Other systems and methods are disclosed.

Abstract: In accordance with an embodiment, a system includes a first transistor and a second transistor. The first transistor has a first input node coupled to a first signal input, a first output node coupled to a first common node, and a first reference node coupled to a first reference voltage, and the second transistor has a second input node coupled to second signal input, a second output node coupled to an output of the system, and a second reference node coupled to the first common node. The system further includes a first switch switchably coupling the first common node to a second reference voltage.

Abstract: This disclosure relates systems and methods for a high bandwidth modulation and transmission of communication signals.

Abstract: A pulse-width modulator (PWM) includes a plurality of comparators for comparing an input signal with a plurality of reference signals and for providing a plurality of corresponding comparison signals. The pulse-width modulator also includes a combinational logic for receiving the plurality of comparison signals and for generating a plurality of binary pulse-width modulation signals on the basis of the plurality of comparison signals. At most only a currently selected binary pulse-width modulation signal of the binary pulse-width modulation signals is at a first signal level at a time. The currently selected binary pulse-width modulation signal is associated to a specific reference signal of the plurality of reference signals which is currently closest to the input signal among the plurality of reference signals in terms of a given amplitude relation between the plurality of reference signals and the input signal.

Abstract: In an embodiment, a method of producing a multi-level RF signal includes producing plurality of pulse-width modulated signals based on an input signal. The method further includes driving a corresponding plurality of parallel amplifiers with the plurality of pulse-width modulated signals by setting a parallel amplifier to have a first output impedance when a corresponding pulse-width modulated signal is in an active state and setting the parallel amplifier to have a second output impedance when the corresponding pulse-width is in an inactive state. The method also includes phase shifting the outputs of the plurality of parallel amplifiers, wherein phase shifting transforms the second output impedance into a third impedance that is higher than the second output impedance, and combining the phase shifted outputs.

Abstract: An apparatus and methods for a baseband modulator configured to code amplitude signals into pulse width modulated time signals comprising at least two amplitude levels is disclosed. A pulse width modulator can receive a component signal of a baseband complex signal and generate a discrete-time pulse width modulated signal. This signal can be converted to a continuous time signal, such as a pulse-width modulated time signal and can be shifted to a carrier signal corresponding respectively to the component signal by a switch. Bursts sequences are generated to an input of a switched amplifier for driving operation of the amplifier therein.

Abstract: This disclosure relates systems and methods for a high bandwidth modulation and transmission of communication signals.

Abstract: In an embodiment, a method of generating a pulse-width modulated signal from an input signal includes calculating a finite number of basis functions of a first pulse-width modulated signal based on the input signal, and forming an electronic output based on the calculated finite number of basis functions.

Abstract: This disclosure relates systems and methods for a high bandwidth modulation and transmission of communication signals.

Abstract: A power amplifier includes a baseband modulator configured to receive a baseband amplitude component and generate a baseband modulated pulse string, an oscillator configured to receive a baseband phase component and generate phase modulated complex carrier signals, a complex up-converter configured to receive and mix the baseband modulated pulse string with the phase modulated complex carrier signals into mixed product signals, and two or more switched mode power amplifiers coupled to the complex up-converter, configured to amplify and switch the mixed product signals at the carrier frequency. The power amplifier further comprises complex filters individually coupled to one of the switch mode power amplifiers, configured to suppress image components in the amplified and switched mixed product signals, and a power combiner coupled to the two or more complex filters, configured to combine the real component of the complex filtered and amplified mixed product signals to generate an RF transmission signal.

Abstract: A signal is modulated by generating a pulse-width modulation signal and applying the pulse-width modulation signal to an input of a switched-mode amplifier. An output of the amplifier is coupled to a filter operable to impart either differential mode oscillations or common mode oscillations at the amplifier output based on the duty cycle of the pulse-width modulation signal. The duty cycle of the pulse-width modulation signal is varied to impart amplitude modulations at the amplifier output.

Abstract: One embodiment of the present invention is a method for producing a system for describing an electrical network. An output signal of the electrical network is sampled at a frequency that corresponds to the Nyquist criterion for the input signal to the electrical network. A model with a memory is developed for the output signal, which is sampled at a low sampling rate, with this model approximating the output signal. The model is then transformed by suitable interpolation to an interpolated model with a memory. The interpolation results in the model created in this way providing a good approximation to an output signal which is sampled at a high frequency. The resultant system can be used for predistortion.

Abstract: This disclosure relates systems and methods for a high bandwidth modulation and transmission of communication signals.

Abstract: An apparatus and methods for a baseband modulator configured to code amplitude signals into pulse width modulated time signals comprising at least two amplitude levels is disclosed. A pulse width modulator can receive a component signal of a baseband complex signal and generate a discrete-time pulse width modulated signal. This signal can be converted to a continuous time signal, such as a pulse-width modulated time signal and can be shifted to a carrier signal corresponding respectively to the component signal by a switch. Bursts sequences are generated to an input of a switched amplifier for driving operation of the amplifier therein.

Abstract: An electrical network having a nonlinear transfer response is approximated with a system with memory. The system with memory being approximated in the frequency domain and subsequently being expanded in the time domain. A transfer response of the system being approximated to a transfer response of the electrical network in a range of a system bandwidth corresponding to an input signal bandwidth. The resulting model has adjustable parameters and can readily be implemented in the form of a dynamically linear filter and a static nonlinearity (B2) connected thereto.

Abstract: In one embodiment, a circuit comprises an adaptive predistorter and a nonlinear element coupled to an output of the predistorter. The predistorter is operative to predistort an input signal according to predistortion control parameters at a given sampling rate. The circuit further comprises an identification unit and a translation unit. The identification unit identifies nonlinearity parameters representing the nonlinearity of the nonlinear element by sampling the output of the nonlinear element at an identification sampling rate lower than twice a bandwidth at the output of the nonlinear element. The translation unit translates the identified nonlinearity parameters into the predistortion control parameters. Other systems and methods are disclosed.

Abstract: A power amplifier includes a baseband modulator configured to receive a baseband amplitude component and generate a baseband modulated pulse string, an oscillator configured to receive a baseband phase component and generate phase modulated complex carrier signals, a complex up-converter configured to receive and mix the baseband modulated pulse string with the phase modulated complex carrier signals into mixed product signals, and two or more switched mode power amplifiers coupled to the complex up-converter, configured to amplify and switch the mixed product signals at the carrier frequency. The power amplifier further comprises complex filters individually coupled to one of the switch mode power amplifiers, configured to suppress image components in the amplified and switched mixed product signals, and a power combiner coupled to the two or more complex filters, configured to combine the real component of the complex filtered and amplified mixed product signals to generate an RF transmission signal.

Abstract: In one embodiment, a circuit comprises an adaptive predistorter and a nonlinear element coupled to an output of the predistorter. The predistorter is operative to predistort an input signal according to predistortion control parameters at a given sampling rate. The circuit further comprises an identification unit and a translation unit. The identification unit identifies nonlinearity parameters representing the nonlinearity of the nonlinear element by sampling the output of the nonlinear element at an identification sampling rate lower than twice a bandwidth at the output of the nonlinear element. The translation unit translates the identified nonlinearity parameters into the predistortion control parameters. Other systems and methods are disclosed.