Self-referencing microwave sensing system

A system for a gas turbine engine, the system comprising:

• a network of a plurality of nodes distributed throughout the gas turbine engine, each of the nodes associated with at least one sensor and/or actuator of the gas turbine engine and operable to communicate through one or more radio frequencies;
• a controller of the gas turbine engine operable to communicate with the network of nodes through the one or more radio frequencies;
• and
• a radio frequency sensing system coupled to the network of nodes, the radio frequency sensing system comprising a waveguide system and a radio frequency transceiver/detector coupled to the waveguide system and configured to:
• emit a calibration signal in the waveguide system to establish a reference baseline between the radio frequency transceiver/detector and a calibration plane associated with an aperture of the waveguide system;
• emit a measurement signal in the waveguide system to transmit a radio frequency signal from the radio frequency transceiver/detector out of the aperture of the waveguide system;
• and
• detect a reflection of the measurement signal at the radio frequency transceiver/detector based on an interaction between the measurement signal and a component of the gas turbine engine, wherein a measurement result of the reflection of the measurement signal is adjusted with respect to a reflection of the calibration signal;
• wherein the waveguide system comprises a power-controlled switch configured to reflect the calibration signal and allow the measurement signal through the power-controlled switch based on a power difference between the calibration signal and the measurement signal.

A method of self-referencing radio frequency sensing in a machine, the method comprising:

• emitting a calibration signal in a waveguide system to establish a reference baseline between a radio frequency transceiver/detector and a calibration plane associated with an aperture of the waveguide system in the machine;
• emitting a measurement signal in the waveguide system to transmit a radio frequency signal from the radio frequency transceiver/detector out of the aperture of the waveguide system;
• reflecting the calibration signal by a power-controlled switch;
• allowing the measurement signal to pass through the power-controlled switch based on a power difference between the calibration signal and the measurement signal;
• detecting a reflection of the measurement signal at the radio frequency transceiver/detector based on an interaction between the measurement signal and a component of the machine;
• and
• determining a calibrated measurement result associated with the component of the machine based on adjusting a measurement result of the reflection of the measurement signal with respect to a reflection of the calibration signal.