WIRELESS AND BATTERYLESS SENSOR

• US 20090167503A1
• Filed: 09/26/2008
• Published: 07/02/2009
• Est. Priority Date: 12/28/2007
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Kumar, Sachin, Dixon, Daniel, Marsh, Brian J., Qasimi, Mohammed A J, Cook, James D.
• Granted Patent: US 7,726,184 B2
• Time in Patent Office: Days
• US Class Current: 340/10.410
• 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 resonant frequency; and

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

a sensor package adapted as a base for mounting and containing said SAW sensor and said antenna.

2. The apparatus of claim 1 wherein said SAW sensor is designed in a stainless steel button package having a sensor diaphragm and along with base sensor package comprises a shape that is adaptable for measuring at least one of pressure and temperature for different applications.

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

4. The apparatus of claim 1 further comprising a passive RFID device included in said sensor package base and connected to an antenna for wireless interrogation of sensor'"'"'s identity (ID) from a nearby Interrogator unit.

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

6. The apparatus of claim 2 wherein said SAW Sensor button is welded onto a threaded stainless steel port and hermetically seals the sensor-antenna assembly from media and exposes the sensor diaphragm to media.

7. The apparatus of claim 2 wherein said SAW Sensor button is mounted onto a threaded plastic port using at least one of an elastomer O-ring and an epoxy, and said SAW sensor button is mounted onto said threaded plastic port in a manner that the sensor-antenna assembly is hermetically sealed from media and exposes the sensor diaphragm to media.

8. The apparatus of claim 2 wherein a non-sensor side of the said SAW Sensor Package base is sealed from external fluids exposures using a cover.

9. The apparatus of claim 1 wherein said Saw Sensor is integrated into a moving object, wherein said surface acoustic wave sensor package measures at least one of media pressure and media temperature within a moving object.

10. The apparatus of claim 1 wherein said apparatus is used for applications requiring intrinsically safe sensor operation such as petrochemical industry applications.

11. A wireless and batteryless sensing apparatus, comprising:

a printed circuit board (PCB) interconnect;

a SAW sensor package with an antenna mounted or formed on said printed circuit board for receiving interrogating radio frequency (RF) signals and transmitting sensor'"'"'s RF response back to the interrogator unit comprising at least one resonant frequency for pressure and/or temperature calculation;

an RFID device and antenna mounted or formed on said printed circuit board with said saw sensor package;

at least one antenna respectively bonded to said SAW sensor package and said RFID device such that said at least one antenna communicates electrically with said SAW sensor package and said RFID device and permits wireless and batteryless interrogation by a remote transceiver;

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

a package cover for sealing said SAW sensor package, PCB Interconnect and said RFID device to provide pressure sensor data and sensor identification thereof.

12. The apparatus of claim 11 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.

13. The apparatus of claim 11 wherein said package base and cover comprise a shape that is adaptable for measuring use in at least one of pressure and temperature.

14. The apparatus of claim 11 wherein said package cover comprises a plastic material.

15. The apparatus of claim 11 wherein said package base further comprises a threaded port made of stainless steel or plastic apart from other suitable material options and said SAW sensor package comprises of a stainless steel button.

16. The apparatus of claim 15 wherein said SAW Sensor button is welded onto said threaded Stainless Steel port in a way which hermetically seals the sensor-antenna and RFID device-antenna assembly from media and exposes the sensor diaphragm to media.

17. The apparatus of claim 15 wherein said SAW Sensor button is mounted onto a threaded plastic port using at least one of an elastomer O-ring and an epoxy and is mounted where the at least one of an elastomer O-ring and epoxy hermetically seals the sensor-antenna and RFID device-antenna assembly from media and exposes the sensor diaphragm to media.