Multi-stage amplifier with shared directional coupler feedback
AssigneeQ-Bit Corporation
InventorChristopher W. Rice
Life of this patent
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Abstract
An n-stage amplifier circuit includes n+1 directional couplers connected in series between the circuit input, the amplifier stages, and the circuit output. Each coupler includes first and third ports forming an inverting interface, and second and fourth ports forming a non-inverting interface, the ports being coupled through suitable windings. Feedback lines are connected between adjacent successive couplers. The interfaces of the couplers are connected such that feedback loops covering one or more contiguous successive amplifier stages provide negative feedback for the amplifier circuit.
Claims10
A two-stage amplifier circuit comprising:
- first and second amplifiers, each amplifier having a signal input and an amplified signal output;
- a first directional coupler coupled to the first amplifier for receiving an input signal to be amplified by the amplifier circuit into an amplified signal, for receiving a first feedback signal, and for providing a signal to the input of the first amplifier;
- a second directional coupler coupled between the first and second amplifiers for receiving a signal from the output of the first amplifier and a second feedback signal, and for providing a signal to the input of the second amplifier and the first feedback signal to the first directional coupler;
- and
- a third directional coupler coupled to the second amplifier for receiving a signal from the output of the second amplifier, for providing the second feedback signal to the second directional coupler, and for providing the amplified signal as an output signal.
A multi-stage amplifier circuit, comprising:
- a plurality of amplifiers arranged in succession from early to late including an earliest and a latest amplifier, each amplifier having a signal input and an amplified signal output;
- an earliest directional coupler coupled to the earliest amplifier for receiving an input signal to be amplified by the amplifier circuit into an amplified signal, and an earliest feedback signal, and for providing a signal to the input of the first amplifier;
- a latest directional coupler coupled to the latest amplifier for receiving a signal from the output of the latest amplifier and providing a latest feedback signal and the amplified signal as outputs;
- and
- a plurality of intermediate directional couplers, each intermediate directional coupler being coupled between an earlier and later successive ones of the plurality of amplifiers and an earlier and a later successive couplers for receiving a signal from the amplified signal output of the earlier amplifier, for receiving the feedback signal from the later successive coupler, for providing a signal to the input of the later amplifier, and for providing a feedback signal to the earlier successive coupler.
Dependencies are inferred from the claim text.