Surface acoustic wave sensor and package

• US 7,726,184 B2
• Filed: 09/26/2008
• Issued: 06/01/2010
• Est. Priority Date: 12/28/2007
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Dixon, Daniel, Kumar, Sachin, Marsh, Brian J., Qasimi, Mohammed A J, Cook, James D.
• Primary Examiner(s): Caputo; Lisa M
• Assistant Examiner(s): Jenkins; Jermaine
• Application Number:
  US12/239,363
• Publication Number:
  US 20090167503A1
• Time in Patent Office: 613 Days
• Field of Search: None
• US Class Current: 73/146.5
• CPC Class Codes: G01L 9/0025 with acoustic surface waves
• CPC Class Codes: H04Q 2209/47 using RFID associated with sensors
• CPC Class Codes: H04Q 2209/84 Measuring functions
• CPC Class Codes: H04Q 2209/88 Providing power supply at the sub-station
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

The SAW sensor in a stainless steel button package having a diaphragm and mounted on a threaded port. Package can hermetically seal a sensor and RFID-antenna assemblies from media. Sensor diaphragm is exposable to media. Sensor and RFID antennas communicate electrically with SAW sensor and RFID device, respectively, for sensor measurements and identification. Antennas receive RF interrogation signal from a nearby interrogator/transceiver and send reflected RF signals back to the interrogator unit containing sensor measurement and sensor ID. TRF signal excites a SAW resonator inside the sensor and causes the SAW to resonate wherein resonant frequency changes with pressure and temperature applied to the sensor. Antennas could be printed circuit board antennas, helical antennas, loop antennas, any other commercially available off-the-shelf antennas or a combination of these.

Claims

1. A wireless and batteryless pressure sensor apparatus, comprising:

a SAW sensor having at least one SAW die with at least one SAW resonator for measuring applied pressure and/or temperature due to change in a resonant frequency of the at least one SAW resonator;

an antenna connected to said SAW sensor such that said antenna is configured to communicate wirelessly with a remote interrogator unit, said antenna configured to receive an interrogating radio frequency (RF) signal, and to transmit an RF response from the SAW sensor back to the remote interrogator unit, the RF response including at least a measure related to the resonant frequency of the at least one SAW resonator representing at least one of pressure and temperature; and

a sensor package including a base for mounting and containing said SAW sensor and said antenna;

wherein said SAW sensor is designed in a stainless steel button package having a sensor diaphragm, and along with said sensor package, comprises a shape that is adaptable for measuring at least one of pressure and temperature.

2. The apparatus of claim 1 wherein said sensor package base comprises a threaded port made of at least one of steel and plastic.

3. The apparatus of claim 1 further comprising a passive RFID device included in said sensor package and connected to an antenna for wireless interrogation of a sensor identity (ID) by the remote interrogator unit.

4. The apparatus of claim 3 wherein at least one of the SAW antenna and RFID antenna comprises at least one of a printed circuit antenna, a helical antenna, and a loop antenna.

5. The apparatus of claim 1 wherein said stainless steel button package is welded onto a threaded stainless steel port to expose at least part of the sensor diaphragm to a media through the port.

6. The apparatus of claim 1 wherein said stainless steel button package is mounted onto a threaded plastic port using at least one of an elastomer O-ring and/or an epoxy, and said stainless steel button package is mounted onto said threaded plastic port to expose at least part of the sensor diaphragm to a media through the plastic port.

7. The apparatus of claim 1 wherein a non-sensor side of the SAW Sensor is sealed from external fluids exposure using a cover.

8. The apparatus of claim 1 wherein said SAW Sensor is integrated into a moving object, wherein said SAW sensor measures at least one of media pressure and media temperature within the moving object.

9. The apparatus of claim 1 wherein said sensor package further includes a cover coupled to the base, the cover and the base together define a cavity that houses the stainless steel button package and the antenna.

10. A wireless and batteryless sensing apparatus, comprising:

a printed circuit board;

a SAW sensor package mounted or formed on said printed circuit board for receiving an interrogating radio frequency (RF) signal from a remote interrogator unit and for transmitting a SAW sensor RF response back to the remote interrogator unit, wherein the RF response includes a measure related to at least one resonant frequency for use in determining pressure and/or temperature;

an RFID device mounted or formed on said printed circuit board with said SAW sensor package;

at least one antenna in communication with said SAW sensor package and/or said RFID device such that said at least one antenna communicates electrically with said SAW sensor package and/or said RFID device and permits wireless and batteryless interrogation of said SAW sensor package and/or said RFID device by the remote interrogator unit;

a package base for mounting said printed circuit board, the SAW Sensor package, and the RFID device; and

a package cover, wherein the package cover and package base together define a cavity for housing said SAW sensor package, printed circuit board and said RFID device.

11. The apparatus of claim 10 wherein said SAW sensor package further comprises a sensor diaphragm and a surface acoustic wave sensing element for use in measuring at least one of pressure and temperature.

12. The apparatus of claim 11 wherein said package base further comprises a threaded port made of stainless steel or plastic, and said SAW sensor package includes stainless steel.

13. The apparatus of claim 12 wherein said threaded port is made of stainless steel and said SAW sensor package, in the form of a stainless steel button, is welded onto said threaded port in a way that protects a non-sensing side of the SAW sensor package, the at least one antenna, and the RFID device from a media while exposing the sensor diaphragm to the media.

14. The apparatus of claim 12 wherein said threaded port is made of plastic and the SAW sensor package is in the form of a stainless steel button package, and the SAW sensor package is mounted onto said threaded port using at least one of an elastomer O-ring and an epoxy, and is mounted such that the at least one of the elastomer O-ring and epoxy seals a non-sensing side of the SAW sensor package, at least one antenna, and RFID device from a media while exposing the sensor diaphragm of the SAW sensor package to the media.

15. The apparatus of claim 10 wherein said package base and package cover comprise a shape that is adaptable for measuring use in at least one of pressure and temperature.

16. The apparatus of claim 10 wherein said package cover comprises a plastic material.