Surface acoustic wave based micro-sensor apparatus and method for simultaneously monitoring multiple conditions
First Claim
1. A SAW-based micro-sensor apparatus, comprising:
- a piezoelectric containing substrate having a piezoelectric containing diaphragm that supports an inertial mass; and
at least one sensing element configured as a SAW device;
wherein said SAW device is for monitoring a plurality of conditions, including at least one of the following conditions;
temperature-compensated acceleration/vibration and a temperature;
wherein said piezoelectric containing diaphragm includes a tensile stress region, a compressive stress region and a boundary between the tensile stress region and the compressive stress region; and
wherein said SAW device includes one or more acceleration/vibration sensitive elements supported by said tensile stress region of said piezoelectric containing diaphragm adjacent said inertial mass.
1 Assignment
0 Petitions
Accused Products
Abstract
A SAW-based micro-sensor apparatus for simultaneously monitoring acceleration/vibration and temperature utilizing a sensing element configured as a SAW device (e.g., SAW resonator or SAW delay line). The SAW device can be located in different locations on a substrate with respect to a thin piezoelectric diaphragm comprising an inertial mass. The temperature-compensated acceleration/vibration can be measured utilizing a frequency difference between an acceleration sensitive SAW resonator (e.g., SAW-g) and a temperature sensitive SAW resonator (e.g., SAW-T). The temperature can be measured utilizing a frequency shift provided by the SAW-T and a temperature reference SAW resonator (e.g., SAW-R). Similarly, the phase response of different reflectors of the SAW delay line can be utilized to differentially measure the acceleration/vibration and temperature.
-
Citations
21 Claims
-
1. A SAW-based micro-sensor apparatus, comprising:
-
a piezoelectric containing substrate having a piezoelectric containing diaphragm that supports an inertial mass; and at least one sensing element configured as a SAW device; wherein said SAW device is for monitoring a plurality of conditions, including at least one of the following conditions;
temperature-compensated acceleration/vibration and a temperature;wherein said piezoelectric containing diaphragm includes a tensile stress region, a compressive stress region and a boundary between the tensile stress region and the compressive stress region; and wherein said SAW device includes one or more acceleration/vibration sensitive elements supported by said tensile stress region of said piezoelectric containing diaphragm adjacent said inertial mass. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. A SAW-based micro-sensor apparatus, comprising:
-
a piezoelectric containing substrate; and at least one sensing element configured as a SAW device, wherein said SAW device is capable of being located in different positions on said piezoelectric containing substrate with respect to a piezoelectric containing diaphragm that comprises an inertial mass; wherein said SAW device is for monitoring a plurality of conditions, including at least one of the following conditions;
temperature-compensated acceleration/vibration and a temperature thereto;wherein said SAW device comprises at least one SAW resonator, and said at least one SAW resonator further comprising; a temperature sensitive SAW resonator located on a stress free region above said inertial mass; an acceleration sensitive SAW resonator located on a tensile stress region of said piezoelectric containing diaphragm near said inertial mass; a temperature reference SAW resonator located on a rim of said piezoelectric containing substrate; wherein said temperature compensated acceleration/vibration is measured utilizing a frequency difference between said acceleration sensitive SAW resonator and said temperature sensitive SAW resonator; and said temperature is measured utilizing a frequency shift provided by said temperature sensitive SAW resonator and said temperature reference SAW resonator.
-
-
15. A SAW-based micro-sensor apparatus, comprising:
-
a piezoelectric substrate having a piezoelectric diaphragm that supports an inertial mass; at least one sensing element configured as a SAW device; where said SAW device is for monitoring a plurality of conditions, including at least one of the following conditions;
temperature-compensated acceleration/vibration and a temperature; andwherein said SAW device comprises at least a SAW delay line, wherein said SAW delay line further comprises; at least one interdigital transducer located on a stress free region above said inertial mass; a plurality of acceleration/vibration sensitive reflectors located on a tensile stressed region of said piezoelectric diaphragm, and a plurality of temperature sensitive reflectors located on said tensile stressed region of said diaphragm, wherein said plurality of temperature sensitive reflectors is tilted with different angles with respect to a direction of said inter-digital transducer for said temperature measurement.
-
-
16. A SAW-based micro-sensor apparatus, comprising:
-
a piezoelectric containing substrate having a piezoelectric containing diaphragm that supports an inertial mass; at least one sensing element configured as a SAW device; wherein said SAW device is for monitoring a plurality of conditions, including at least one of the following conditions;
temperature-compensated acceleration/vibration and a temperature; andwherein said SAW device comprises at least a SAW delay line, wherein said SAW delay line further comprises; at least one interdigital transducer located on a stress free region on a rim of the piezoelectric containing substrate outside the said piezoelectric containing diaphragm; a plurality of acceleration/vibration sensitive reflectors located on a tensile stressed region of said piezoelectric containing diaphragm; and a plurality of temperature sensitive reflectors located on said stress free region on the rim of the piezoelectric containing substrate outside said piezoelectric containing diaphragm, wherein said plurality of temperature sensitive reflectors is tilted with different angles with respect to a direction of said inter-digital transducer for said temperature measurement.
-
-
17. A SAW-based micro-sensor apparatus, comprising:
-
a piezoelectric containing substrate; and at least one sensing element configured as a SAW device, wherein said SAW device is capable of being supported by different portions of said piezoelectric containing substrate with respect to a piezoelectric containing diaphragm that comprises an inertial mass; wherein said SAW device is for monitoring a plurality of conditions, including at least one of the following conditions;
temperature-compensated acceleration/vibration and a temperature thereto;wherein said piezoelectric containing substrate includes a tensile stressed region and a compressive stressed region and a boundary therebetween; and wherein said SAW device comprises a saw resonator, the saw resonator comprises one or more acceleration/vibration sensitive elements supported by either the tensile stressed region or the compressive stressed region, but not both of the tensile stressed region and the compressive stressed region. - View Dependent Claims (18, 19, 20, 21)
-
Specification