DAC based switching power amplifier
AssigneeBroadcom Corporation
InventorsAhmadreza (Reza) Rofougaran, Amin Shameli
Life of this patent
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Abstract
A power amplifier for use in a transmitter includes a first transistor having an input, a first node and a second node, a second transistor having an input, a first node and a second node and a digital to analog conversion module. The input of the first transistor is operably coupled to receive a first input, while the input of the second transistor is operably coupled to receive a second input. The second nodes of the first and second transistors provide an output of the power amplifier. The digital to analog conversion module is operably coupled to control current through the first and second transistors based on at least one of a power control signal and an amplitude modulation control signal.
Claims21
A power amplifier for use in a transmitter, comprising:
- a first transistor having an input, a first node and a second node, wherein the input of the first transistor is operably coupled to receive a first input;
- a second transistor having an input, a first node, and a second node, wherein the input of the second transistor is operably coupled to receive a second input;
- and
- a digital to analog conversion module operably coupled to control current through the first and second transistors based on at least one of a power control signal and an amplitude modulation control signal, wherein outputs of the second nodes of the first and second transistors provide an output of the power amplifier.
A polar transmitter, comprising:
- a modulator operably coupled to receive an outgoing digital signal and operable to digitally modulate the outgoing digital signal to produce a phase-modulated digital signal and an amplitude-modulated digital signal;
- first and second Digital-to-Analog converters (DACs) for converting the phase-modulated digital signal and the amplitude-modulated digital signal, respectively, from digital signals to analog signals to produce a phase-modulated analog signal and an amplitude-modulated analog signal;
- a phase locked loop operably coupled to receive the phase-modulated analog signal and to up-convert the phase-modulated analog signal from an IF frequency to an RF frequency to produce a phase-modulated RF signal;
- and
- a power amplifier for producing a modulated RF signal based on the phase-modulated RF signal and the amplitude-modulated analog signal, wherein the power amplifier further includes:
- a first transistor having an input, a first node and a second node, wherein the input of the first transistor is operably coupled to receive a first input,
- a second transistor having an input, a first node, and a second node, wherein the input of the second transistor is operably coupled to receive a second input, and
- a digital to analog conversion module operably coupled to control current through the first and second transistors based on at least a power control signal and the amplitude-modulated analog signal, wherein outputs of the second nodes of the first and second transistors provide an output of the power amplifier.
A method for producing an amplified modulated radio frequency (RF) signal, comprising:
- providing a differential switch pair and a digital to analog conversion module operably coupled to the differential switch pair;
- receiving a phase-modulated RF signal at an input of the differential switch pair;
- receiving an amplitude-modulated signal at the digital to analog conversion module;
- generating a bias current for biasing the differential switch pair by the digital to analog conversion module, the bias current being proportional to the amplitude-modulated signal;
- and
- producing the amplified modulated RF signal at an output of the differential switch pair in response to the phase-modulated RF signal and the bias current, the outbound modulated RF signal having an amplitude proportional to the amplitude-modulated signal.
Dependencies are inferred from the claim text.