High frequency infrared emitter
AssigneeRaytheon Company
InventorsAthanasios J. Syllaios, Roland W. Gooch, William L. McCardel, Thomas R. Schimert
Life of this patent
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Abstract
An infrared radiation emitter is provided that is capable of producing infrared radiation modulating at high frequency. The IR emitter includes a low-thermal-mass resistive membrane that is suspended by long thermal isolation arms over a substrate. The membrane is suspended over the substrate such that a resonant emitting cavity is formed between the membrane and the substrate. The low-mass, thermally isolated membrane design maximizes the temperature change induced by Joule heating of the resistive membrane and allows the emitted IR radiation to be modulated at high frequencies.
Claims24
An infrared emitter comprising:
- a membrane having a thermal mass sufficiently low to emit infrared radiation modulating at high frequency in response to a modulating electric current passing therethrough;
- a substrate from which the membrane is thermally isolated and over which the membrane is supported in order to form a cavity between the membrane and a top surface of the substrate;
- a pair of conductor arms coupled to the membrane and operable to conduct electrical current to and from the membrane and to thermally isolate the membrane from the substrate;
- and
- a pair of support legs, each support leg coupled to the substrate at a first end and coupled to a respective conductor arm at a second end, each support leg operable to conduct electrical current from the substrate to a respective conductor arm.
An infrared emitter array comprising:
- a substrate;
- a plurality of infrared emitters coupled to the substrate, each infrared emitter comprising:
- a membrane having a thermal mass sufficiently low to emit infrared radiation modulating at high frequency in response to a modulating electric current passing therethrough;
- the membrane supported over the substrate in order to form a cavity between the membrane and a top surface of the substrate;
- a pair of conductor arms coupled to the membrane and operable to conduct electrical current to and from the membrane and to thermally isolate the membrane from the substrate;
- and
- a pair of support legs, each support leg coupled to the substrate at a first end and coupled to a respective conductor arm at a second end, each support leg operable to conduct electrical current from the substrate to a respective conductor arm.
An infrared emission system comprising:
- infrared radiation source having at least one infrared emitter comprising:
- a multi-layer membrane having a thermal mass sufficiently low to emit infrared radiation modulating at high frequency in response to a modulating electric current passing therethrough;
- a substrate from which the membrane is thermally isolated and over which the membrane is supported in order to form a cavity between the membrane and the substrate;
- a pair of conductor arms coupled to the membrane and operable to conduct electrical current to and from the membrane and to thermally isolate the membrane from the substrate;
- and
- a pair of support legs, each support leg coupled to the substrate at a first end and coupled to a respective conductor arm at a second end, each support leg operable to conduct electrical current from the substrate to a respective conductor arm;
- a programmable electrical power source operable to transmit an electrical current to the at least one infrared emitter;
- and
- an input device operable to transmit a signal to the programmable electrical power source indicating the amount of electrical current to be sent to the at least one infrared emitter at any given instant.
A method of emitting infrared radiation modulating at high frequency comprising:
- providing a membrane comprising an emitter layer;
- suspending the membrane over a substrate such that a cavity is created between the membrane and a top surface of the substrate, and such that the membrane is thermally isolated from the substrate;
- passing an electrical current through the emitter layer to cause the emitter layer to emit infrared radiation;
- and
- modulating the electrical current passed through the emitter layer at a frequency corresponding with the desired modulation frequency of the infrared radiation.
Dependencies are inferred from the claim text.