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US 8,508,294 B2Granted
Power amplifier with feedback impedance for stable output
AssigneeMarvell World Trade Ltd.
InventorsKan Li, Poh Boon Leong, Sehat Sutardja
Life of this patent
Estimating the term…
Abstract
In one embodiment, an apparatus includes an amplifier circuit having a phase shift. The amplifier circuit amplifies a signal for wireless transmission. A feedback circuit is coupled to the amplifier circuit and includes a capacitor. An input impedance to the amplifier circuit has a same impedance characteristic as a feedback circuit impedance of the feedback circuit. A total phase shift of the signal for the amplifier circuit and the feedback circuit is less than a threshold.
Claims20
An apparatus comprising:
- an amplifier circuit having a phase shift, wherein the amplifier circuit is configured to amplify a signal for wireless transmission;
- and
- a feedback circuit coupled to the amplifier circuit, wherein:
- feedback components of the feedback circuit are selected based on a feedback factor that analyzes an input impedance provided by input components to the amplifier circuit and the feedback components of the feedback circuit,
- the feedback components are selected such that the feedback factor indicates the feedback components have a same impedance characteristic as the input impedance of the input components,
- the feedback components are selected such that the feedback factor indicates a total phase shift of the signal, for the amplifier circuit and the feedback circuit, is less than a threshold, and
- the feedback components include a capacitor.
4 more elements
A system comprising:
- a first amplifier stage configured to amplify a signal for wireless transmission;
- a resonant tank circuit configured to receive the signal from the first amplifier stage, wherein the first amplifier stage and the resonant tank circuit introduce a first phase shift in the signal;
- a second amplifier stage configured to amplify the signal from the resonant tank circuit;
- a transformer configured to receive the signal from the second amplifier stage, wherein the second amplifier stage and the transformer introduce a second phase shift in the signal;
- and
- a feedback circuit coupled to the second amplifier stage, wherein:
- feedback components of the feedback circuit are selected based on a feedback factor that analyzes an input impedance provided by input components to the amplifier circuit and the feedback components of the feedback circuit,
- the feedback components are selected such that the feedback factor indicates the feedback components have a same impedance characteristic as the input impedance of the input components,
- the feedback components are selected such that the feedback factor indicates a total phase shift of the signal transferred through a feedback loop is less than a threshold, the feedback loop including the first amplifier stage, resonant tank circuit, second amplifier stage, and the feedback circuit, and
- the feedback components include a capacitor.
7 more elements
A method comprising:
- amplifying a signal for wireless transmission through an amplifier circuit;
- and
- coupling the signal through a feedback circuit coupled to the amplifier circuit, wherein:
- feedback components of the feedback circuit are selected based on a feedback factor that analyzes an input impedance provided by components to the amplifier circuit and the feedback components of the feedback circuit,
- the feedback components are selected such that the feedback factor indicates the feedback components have a same impedance characteristic as the input impedance of the input components,
- the feedback components are selected such that the feedback factor indicates a total phase shift of the signal, for the amplifier circuit and the feedback circuit, is less than a threshold, and
- the feedback components include a capacitor.
4 more elements
Dependencies are inferred from the claim text.