Continuously variable active reactance systems and methods
AssigneeEtherdyne Technologies, Inc.
InventorRobert A. Moffatt
Life of this patent
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Abstract
Various embodiments for controlling a resonant frequency of a resonator are described. A system includes at least one resonant circuit and an active variable reactance circuit that controls a resonant frequency of the at least one resonant circuit. The active variable reactance circuit includes an electrically-controllable switching element and a switch controller sub-circuit configured to switch the electrically-controllable switching element at a frequency of a radio-frequency (RF) current or voltage passing through or across a device such that the RF current flowing from a first terminal to a second terminal is substantially sinusoidal.
Claims23
A system, comprising:
- an active variable reactance circuit, comprising:
- an electrically-controllable switching element;
- a passive reactive component connected to at least one terminal of the electrically-controllable switching element;
- a resonator connected to the at least one terminal of the electrically-controllable switching element;
- a radiofrequency (RF) pickup component configured to generate a pickup voltage proportional to an RF current or voltage passing through or across the resonator;
- a switch controller sub-circuit that receives the pickup voltage and a control voltage, and generates a switch control signal having a duty cycle based on the control voltage and a phase based on the pickup voltage that switches the electrically-controllable switching element at a frequency of the RF current or voltage passing through or across the resonator,
- wherein the switch controller sub-circuit comprises a comparator and an op-amp feedback loop, wherein the comparator receives the pickup voltage as a first input and a comparison voltage as a second input, the comparison voltage being an output of the op-amp feedback loop,
- wherein the op-amp feedback loop receives the switch control signal as a first input and the control voltage as a second input, and outputs the comparison voltage to the comparator.
A method, comprising:
- controlling, by an active variable reactance circuit, a resonant frequency of at least one resonant circuit by:
- providing an electrically-controllable switching element;
- providing a passive reactive component connected to at least one terminal of the electrically-controllable switching element, and a resonator connected to the at least one terminal of the electrically-controllable switching element;
- generating, by a radiofrequency (RF) pickup component, a pickup voltage proportional to an RF current or voltage passing through or across the resonator;
- receiving, by a switch controller sub-circuit, the pickup voltage and a control voltage, and generating, by the switch controller sub-circuit, a switch control signal having a duty cycle based on the control voltage and a phase based on the pickup voltage that switches the electrically-controllable switching element at a frequency of the RF current or voltage passing through or across the resonator, wherein the switch controller sub-circuit comprises a comparator and an op-amp feedback loop;
- receiving, by the comparator, the pickup voltage as a first input and a comparison voltage as a second input, the comparison voltage being an output of the op-amp feedback loop;
- and
- receiving, by the op-amp feedback loop, the switch control signal as a first input and the control voltage as a second input, and providing, by the op-amp feedback loop, the comparison voltage to the comparator.
Dependencies are inferred from the claim text.