Electromagnetic resonant sensor
AssigneeRosemount Inc.
InventorRoger L. Frick
Life of this patent
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Abstract
An electromagnetic resonant sensor has a dielectric sensor body through which electromagnetic wave energy is propagated. The sensor body has a cavity, with surfaces facing one another to define a gap that varies as a function of a parameter to be measured. The resonant frequency of an electromagnetic standing wave in the body and the variable gap changes as a function of the gap dimension.
Claims36
For use with a source of electromagnetic energy, a sensor for measuring a measurable parameter, the sensor comprising:
- an electromagnetic resonator, disposed to receive at least a portion of the electromagnetic energy, the electromagnetic resonator having a dielectric body with a sensing surface responsive to changes in the measurable parameter at the sensing surface and the electromagnetic resonator defining a cavity forming a variable gap that varies in response to the sensing surface and that is positioned such that a resonant frequency associated with an electromagnetic standing wave in the dielectric body and the variable gap changes in response to changes in the measurable parameter.
For use with a source of electromagnetic energy, a sensor for use in measuring a measurable parameter, the sensor comprising:
- a resonator having a dielectric body with a variable cavity gap responsive to changes in the measurable parameter at a sensing surface, the resonator defining a resonant frequency of a standing electromagnetic wave in the dielectric body and the variable cavity gap that is dependent upon the measurable parameter at the sensing surface, the resonator being disposed such that a signal from the sensor is a function of the resonant frequency.
An apparatus for modulating, based on a measurable parameter, the output of a source producing electromagnetic energy, the apparatus comprising:
- a coupler coupled to receive the energy;
- and
- a high Q resonator having a dielectric body with a variable configured to produce an effective dielectric constant that varies in response to changes in the measurable parameter, the high Q resonator coupled to the coupler for receiving the energy and creating an electromagnetic standing wave within the dielectric body and the variable cavity gap at a resonant frequency that is a function of the measurable parameter.
The apparatus of claim 35, wherein the measurable parameter is selected from the group consisting of pressure, temperature, flow rate, material composition, force, and strain.
A variable frequency resonator comprising an electromagnetic resonator having a dielectric body and a cavity defining a variable gap, the resonator producing an output at a resonant frequency that is dependent upon the variable gap which is disposed to alter a ratio of stored electric field and magnetic field energy of an electromagnetic standing wave in response to changes in the measurable parameter.
A method of sensing a measurable parameter, the method comprising:
- providing a resonator characterized by a resonant frequency that is a function of a variable gap in an internal cavity of a dielectric body of the resonator, the variable gap being responsive to the measurable parameter;
- supplying electromagnetic energy to the resonator to produce an electromagnetic standing wave in the dielectric body and the variable gap;
- and
- sensing a resonant frequency of the electromagnetic standing wave to determine the measurable parameter.
A method of sensing a measurable parameter, the method comprising the steps of:
- providing a pulsed electromagnetic signal characterized by a repetition rate;
- providing a resonator having a dielectric body with a variable gap that varies in response to changes in the measurable parameter;
- supplying the pulsed electromagnetic signal to the resonator to produce a pulsed electromagnetic wave pattern in the dielectric body and the variable gap;
- and
- sensing variations in the repetition rate of the pulsed electromagnetic signal in response to variations in the variable gap.
For use with a electromagnetic source, a resonator having a dielectric body with a variable gap that varies in response to changes in a measurable parameter, the resonator receiving electromagnetic energy from the source to produce an electromagnetic standing wave in the dielectric body and the variable gap so that a characteristic of the energy changes in response to variations in the variable gap.
The resonator of claim 30, wherein the electromagnetic energy is a continuous wave and the characteristic is frequency.
The resonator of claim 30, wherein the electromagnetic energy is a pulsed energy and the characteristic is repetition rate.
An electromagnetic resonant sensor comprising:
- a sensor body;
- and
- a cavity within the sensor body having a variable gap between interior surfaces of the sensor body that varies as a function of a measurable parameter, the cavity being positioned within the sensor body so that an electromagnetic standing wave is formed within the body and the variable gap, and a resonant frequency of the sensor is a function of the measurable parameter.
An electromagnetic resonant sensor for receiving electromagnetic energy and producing an output based upon an electromagnetic standing wave having a resonant frequency that is a function of a parameter to be measured, the sensor characterized by a dielectric body with a variable gap that changes dimension as a function of the parameter, the dielectric body and the variable gap being configured so that the electromagnetic standing wave extends within the dielectric body and the variable gap and a change in gap dimension causes a change in the resonant frequency.
Dependencies are inferred from the claim text.