MEMS SAW sensor
AssigneeHoneywell International Inc.
InventorsCornel P. Cobianu, Ioan Pavelescu, James D. Cook
Life of this patent
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Abstract
Devices and methods for acoustically measuring temperature and pressure are disclosed. An illustrative SAW sensor can include an electrode structure that transmits and receives surface acoustic waves along a SAW delay line, a temperature sensor for measuring temperature along a first direction of the SAW delay line, and a pressure sensor for measuring pressure along a second direction of the SAW delay line. The SAW sensor can include an antenna that wirelessly transmits and receives RF signals to and from an electrical interrogator unit that can be used to power the SAW sensor.
Claims59
A SAW sensor for sensing temperature and pressure within an environment, comprising:
- an electrode structure that transmits and receives surface acoustic waves along a SAW delay line of the sensor;
- temperature sensing means for sensing temperature within the environment, said temperature sensing means structured to reflect surface acoustic waves transmitted along a first direction of the SAW delay line;
- and
- pressure sensing means for sensing pressure within the environment, said pressure sensing means structured to reflect surface acoustic waves transmitted along a second direction of the SAW delay line;
- wherein the first and second directions are relative to the same SAW delay line.
A SAW sensor for sensing temperature and pressure within an environment, comprising:
- a piezoelectric substrate having a top surface;
- an interdigital transducer coupled to the top surface of the substrate, said interdigital transducer structured to transmit and receive surface acoustic waves along a SAW delay line of the sensor;
- one or more temperature sensing reflectors structured to reflect surface acoustic waves transmitted along a first direction of the SAW delay line;
- a diaphragm having a compressive zone and a stretched zone;
- and
- one or more pressure sensing reflectors disposed on the compressive zone of the diaphragm and adapted to reflect surface acoustic waves transmitted along a second direction of the SAW delay line.
A SAW sensor for sensing temperature and pressure within an environment, comprising:
- an electrode structure that transmits and receives surface acoustic waves along a SAW delay line of the sensor;
- a single temperature sensing reflector that reflects surface acoustic waves transmitted along a first direction of the SAW delay line;
- a diaphragm having a compressive zone and a stretched zone;
- a single pressure sensing reflector disposed on the compressive zone of the diaphragm and that reflects surface acoustic waves transmitted along a second direction of the SAW delay line;
- and
- a single reference reflector that provides a referenced phase response for both temperature and pressure measurement of the SAW sensor.
A SAW sensor for sensing temperature and pressure within an environment, comprising:
- an interdigital transducer that transmits and receives surface acoustic waves along a SAW delay line of the sensor;
- temperature sensing means for sensing temperature within the environment, said temperature sensing means structured to reflect surface acoustic waves transmitted along a first direction of the SAW delay line;
- pressure sensing means for sensing pressure within the environment, said pressure sensing means structured to reflect surface acoustic waves transmitted along a second direction of the SAW delay line;
- wherein the first and second directions are relative to the same SAW delay line;
- means for wirelessly receiving a power signal to power the SAW sensor;
- and
- means for wirelessly transmitting an RF response signal from the SAW sensor.
A sensor system for acoustically sensing temperature and pressure within an environment, comprising:
- a SAW sensor including an electrode structure that transmits and receives surface acoustic waves along a SAW delay line, said SAW sensor including temperature sensing means for measuring temperature along a first direction of the SAW delay line and pressure sensing means for measuring pressure along a second direction of the SAW delay line;
- wherein the first and second directions are relative to the same SAW delay line;
- means for wirelessly providing power to the SAW sensor;
- and
- means for wirelessly transmitting an RF response signal from the SAW sensor.
A method of wirelessly and passively measuring temperature and pressure within an environment, comprising the steps of:
- providing a SAW sensor including an electrode structure that transmits and receives surface acoustic waves along a SAW delay line having a +x direction and a −x direction;
- wirelessly powering the electrode structure and transmitting incident surface acoustic waves in both the +x direction and −x direction of the SAW delay line;
- providing one or more temperature sensing reflectors in acoustic communication with the +x direction of the SAW delay line, said one or more temperature reflectors structured to reflect echo signals back to the electrode structure;
- providing a diaphragm and one or more pressure sensing reflectors in acoustic communication with the −x direction of the SAW delay line, said one or more pressure sensing reflectors structured to reflect echo signals back to the electrode structure;
- outputting a wireless RF response signal;
- and
- analyzing the RF response signal to obtain a measure of the temperature and pressure within the environment.
Dependencies are inferred from the claim text.