Apparatus and method for radio frequency power and standing wave ratio measurement
AssigneeRockwell Collins, Inc.
InventorsTimothy L. Kean, David L. Krett, Ted J. Hoffman, Edward J. Anthony
Life of this patent
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Abstract
A magnitude of radio frequency voltage and current, input into a load from a radio frequency power source, are measured at a single point along a transmission line. Phase difference between voltage and current is also measured. These measurements are used to compute VSWR and forward input power. The computed measurements may be compared against predetermined VSWR limits, and operation of the radio frequency power source can be adjusted to prevent damage to the detection apparatus or load.
Claims20
A method of determining a power and a standing wave ratio in an input signal delivered to a load comprising:
- sampling an amplitude of voltage at a point in a transmission line;
- sampling, using a balun, an amplitude of current at substantially the same point in the transmission line;
- determining a phase difference between the voltage and the current;
- and
- calculating a power and a standing wave ratio delivered to the load.
An apparatus for determining a power and a standing wave ratio comprising:
- a means for sampling a voltage of a radio frequency input signal at a point in a transmission line;
- a means for sampling a current of the radio frequency input signal at substantially the same point in the transmission line;
- wherein said means for sampling a current comprises a balun;
- a means for determining a phase difference between the voltage and the current of the radio frequency input signal;
- and
- a means for calculating a power and a standing wave ratio from voltage, current and phase difference.
A system for controlling a radio frequency signal input into a load comprising:
- a means for sampling a voltage of the radio frequency signal at a point in a transmission line;
- a means for sampling a current of the radio frequency signal at substantially the same point in the transmission line;
- wherein said means for sampling a current comprises a balun;
- a means for determining a phase difference between the voltage and the current of the radio frequency signal;
- a means for applying one or more algorithms to calculate a power and a standing wave ratio using voltage, current and phase difference;
- and
- a means for modifying the input signal based on a standing wave ratio calculation.
Dependencies are inferred from the claim text.