Methods and systems for modulating an amplifier power supply to efficiently attain amplified RF output power with much lower power dissipation than existing amplifiers. In a cable television (CATV) network, a processor receives a signal to be amplified by an amplifier at a location remote from the processor. A bias point of the amplifier may be variably modulated based on peaks of an input signal to reduce amplifier dissipation.

There is provided a filter for receiving a rectangular or stepped source voltage to be filtered and for providing an output voltage, the filter including means arranged to determine the output voltage in dependence on the frequency components of the source voltage within the filter passband, and independent of output current drawn.

Aspects of the present disclosure are generally directed to a power supply for generating an output supply voltage. The power supply generally includes a variable voltage supply configured to generate an intermediate supply voltage based on a reference signal, a correction circuit configured to generate an error signal based on the output supply voltage or the intermediate supply voltage, and a combiner configured to combine the intermediate supply voltage and the error signal to provide the output supply voltage.

A novel and useful radio frequency (RF) front end module (FEM) circuit that provides high linearity and power efficiency and meets the requirements of modern wireless communication standards such as 802.11 WLAN, 3G and 4G cellular standards, Bluetooth, ZigBee, etc. The configuration of the FEM circuit permits the use of common, relatively low cost semiconductor fabrication techniques such as standard CMOS processes. The FEM circuit includes a power amplifier made up of one or more sub-amplifiers having high and low power circuits and whose outputs are combined to yield the total desired power gain. An integrated multi-tap transformer having primary and secondary windings arranged in a novel configuration provide efficient power combining and transfer to the antenna of the power generated by the individual sub-amplifiers.

A power supply for a radio frequency (RF) power amplifier that amplifies an RF input signal into an RF output signal and a method of operation in the power supply. The power supply comprises a first power converter to convert an input voltage to the power supply into a first supply voltage of the RF power amplifier. The power supply comprises a second power converter to receive the input voltage and the first supply voltage and to selectively convert either the input voltage or the first supply voltage into at least a portion of a second supply voltage of the RF power amplifier.

An apparatus for and method of a supply modulator (SM) for a power amplifier (PA) is provided. The apparatus includes a buck-boost converter, including a supply input connected to a battery voltage (Vbat), and an output; a switch and capacitors module, including a first input connected to the output of the buck-boost converter, and a second input; a buck (dual) converter, including a supply input connected to Vbat, an input connected to the output of the buck-boost converter, and an output connected to the second input of the switch and capacitors module; a linear amplifier (LA), including a supply input connected to the output of the buck-boost converter, an input, and an output connected to the second input of the switch and capacitors module; and the PA, including a supply input connected to the output of the buck (dual converter, an input for receiving a radio frequency (RF) signal, and an output for outputting an RF signal.

Embodiments of the disclosure may include a method and apparatus for improving the efficiency and extending the operation time between recharges or replacement batteries of a portable audio delivery system. The audio delivery system may include a processor, an audio processing device, a speaker, and a rechargeable power source. The audio delivery system is generally configured to generate and/or receive an audio input signal and efficiently deliver an amplified, high quality audio output signal to a user. In some embodiments of the disclosure, the audio processing device of the audio delivery system may include a switch mode power supply (SMPS), a signal delay element, an envelope detector, and a switching signal amplifier.

An amplifier has an input port for receiving an input signal and an envelope port for receiving an envelope signal indicative of an envelope of the input signal, and an output port for delivering an amplified signal. The amplifier has a first transistor and a second transistor. A first biasing circuit is coupled to the envelope port and is arranged to generate a first bias voltage dependent on the envelope signal. A summing stage is coupled to the input port for receiving the input signal, to the first biasing circuit for receiving the first bias voltage, and to the gate of the first transistor. A second biasing circuit is coupled between the envelope port and the gate of the second transistor, and is arranged to generate a second bias voltage dependent on the envelope signal.

Aspects of the disclosure provide a circuit that includes an envelope processing circuitry and a voltage modulator. The envelope processing circuitry is configured to receive a stream of envelope values of a signal for transmission and output a supply modulation signal in response to the stream of envelope values based on an average-power-tracking (APT) calibration. The voltage modulator is configured to modulate a supply voltage to an amplifier according to the supply modulation signal. The amplifier operates under the supply voltage to amplify the signal for transmission.

An apparatus for and method of a supply modulator (SM) for a power amplifier (PA) is provided. The apparatus includes a buck-boost converter, including a supply input connected to a battery voltage (Vbat), and an output; a switch and capacitors module, including a first input connected to the output of the buck-boost converter, and a second input; a buck (dual) converter, including a supply input connected to Vbat, an input connected to the output of the buck-boost converter, and an output connected to the second input of the switch and capacitors module; a linear amplifier (LA), including a supply input connected to the output of the buck-boost converter, an input, and an output connected to the second input of the switch and capacitors module; and the PA, including a supply input connected to the output of the buck (dual converter, an input for receiving a radio frequency (RF) signal, and an output for outputting an RF signal.