Patent Application
20120188133
The invention relates to a wireless sensor device, system and method including a handle/antenna component and probe shaft sensor. More particularly, a spiralpole antenna configured with a surface acoustic wave (SAW) device for wireless temperature sensing.
Temperature sensing of objects being heated can be problematic. Inherently high temperatures limit materials eligible to be used as components. Confinement in enclosures such as ovens can impair direct visual readings. Electromagnetic radiation from heat sources can further limit candidate solutions. Overall size of sensors can be further limited due to the size of the enclosure or dimensions of the object being heated. When multiple objects or multiple locations are simultaneously being heated and sensed, discrimination between sensors can be difficult. Motion within the heating environment can create variations in performance. When flexibility, accuracy and reliability are emphasized, cost and complexity can be deterrents.
Embodiments include a system for wireless sensing, the system comprising a spiral-dipole (“spiralpole”) antenna; a probe shaft comprising electrical connection; an acoustic wave device (AWD) sensor device in electrical communication with the spiralpole antenna through the probe shaft. Other embodiments provide a method for wireless sensing comprising providing a spiralpole antenna sensor device; transmitting an excitation signal to the antenna of an AWD; receiving the excitation signal at the spiralpole antenna; reacting, at the AWD, to the excitation signal conveyed from the spiralpole antenna; transmitting from the spiralpole antenna a response signal conveyed from the AWD; and receiving, at a receiver, the response signal.
Embodiments provide a probe system for wireless sensing of at least one measurand, the system comprising a spiral-dipole (spiralpole) antenna component; a probe shaft comprising electrical connection; an acoustic wave device (AWD) sensor in electrical communication with the spiralpole antenna through the probe shaft; wherein the system is configured to communicate with an excitation signal generator and response signal receiver. In additional embodiments, the AWD is a surface acoustic wave (SAW) device; and the AWD is a surface acoustic wave (SAW) resonator device. For other embodiments, the measurand comprises temperature; others comprise at least one measurand in addition to temperature, to which the acoustic wave device is sensitive; and in others the measurand is a measurand other than temperature, to which the acoustic wave device is sensitive. For more embodiments, the spiral-dipole antenna component is non-orthogonal to the probe shaft. In further embodiments, multiple probes operate cooperatively through differential operating frequencies of AWD components in each of the multiple probes. For other further embodiments, the radiation pattern of the probe is omnidirectional; and in others performance is direction-independent; whereby movement and orientation of temperature measurement subject does not impact accuracy or resolution of temperature measurement. In continuing embodiments, the spiral-dipole antenna is mismatched, whereby the radiation pattern is broad. Additional embodiments provide that the spiral-dipole antenna component comprises a helical coil; and in others the spiral-dipole antenna component comprises a helical coil and interfaces with the ground arm at a termination of a proximate loop. For some embodiments, the spiral-dipole antenna component comprises a helical coil and interfaces with the ground arm at an intermediate location between terminal ends of the antenna element of the spiral-dipole antenna component.
Further embodiments provide a probe device for wireless sensing of at least one measurand, the device comprising a spiral-dipole (spiralpole) antenna component; a probe shaft component in electrical communication with the spiral-dipole (spiralpole) antenna component; an acoustic wave device (AWD) sensor in electrical communication with the spiralpole antenna through the probe shaft; wherein the device is configured to communicate with an excitation signal generator and response signal receiver.
Yet further embodiments provide a method for wireless sensing comprising providing a spiral-dipole (spiralpole) antenna sensor device; transmitting an excitation signal to the antenna of an acoustic wave device (AWD); receiving the excitation signal at the spiralpole antenna; reacting, at the AWD, to the excitation signal conveyed from the spiralpole antenna; transmitting from the spiralpole antenna a response signal conveyed from the AWD; and receiving, at a receiver, the response signal. In additional embodiments, the operating frequency range is about 400 MHz to about 700 MHz. For other embodiments, the transmitter antenna of the transmitting step and receiving antenna of the receiving step comprise unitary components. For more embodiments, the transmitter antenna of the transmitting step and receiving antenna of the receiving step comprise multiple components. In continuing embodiments, operational field strengths of about 13.5 dB are produced.
The features and advantages described herein are not all-inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings, specification, and claims. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and not to limit the scope of the inventive subject matter.
‘Spiralpole’ (spiral-dipole) antenna embodiments have two radiating parts: the shaft and the one-wing spiral. It performs similarly to a resonant half-wave dipole. A representative dipole's length is:
L
dipole
=L
probe
+L
spiral Eq. (1)
where the spiral length, Lspiral, is measured from the opening of the transmission line. For this embodiment, the resonant frequency of the antenna is given by:
Application environments comprise ovens including, but not limited to, residential microwave ovens, commercial ovens, and conventional thermal ovens. In nonlimiting embodiments the probe is flexible, semi-rigid, and or rigid. The handle, in embodiments, is one-piece, molded over the antenna component. For embodiments, the sensor comprises at least one SAW resonator. The probe antenna radiation pattern, in embodiments, is omnidirectional, multi-lobed, or elliptical. For embodiments, the probe radiation pattern is circularly polarized or of mixed polarization. Antenna radiation performance is considered for the probe in free space, partially embedded, and fully embedded in a subject for temperature measurement. For embodiments, the antenna is mismatched but provides a broad radiation pattern. For further embodiments, the antenna is mismatched and unbalanced. System embodiments comprise matched and unmatched circuits with or without matching components such as a loading coil. In embodiments, antenna components are orthogonal to the probe shaft. In other embodiments, antenna components are not orthogonal to the probe shaft. Antenna embodiments provide a single loop antenna element and multiple, spiral arm, elements. Frequency ranges, in embodiments, comprise about approximately 400 MHz to 700 MHz. Probe lengths, in embodiments, comprise about approximately 15 mm to 200 mm. Transmitter/receiver antennas can be unitary or of multiple component construction. Benefits comprise direction independence of performance; i.e. movement or orientation of the temperature subject does not impact the accuracy or resolution of the temperature measurement. Probe configurations support shorter lengths, smaller overall size for given performance, eased insertion into temperature subjects, support for multiple probes through differential operating frequencies of AWD components in multiple probes, higher field strengths (13.5 dB in embodiments), and sensor evaluation for ‘doneness’ in addition to raw temperature. In embodiments, the measurand includes and is other than temperature. One or more measurands are detected, implemented with one or more acoustic wave devices (AWDs). In embodiments, the SAW sensor is extended to include other AWDs in addition to those considered as ‘surface’ acoustic wave devices. Nonlimiting examples include those sensor devices disclosed in U.S. Pat. Nos. 6,033,852, 7,569,971, 7,667,369, 7,633,206, 7,855,564, 11/875,162, 12/610,642, 12/429,300, 12/884,931, and 61/411,130 (provisional application), whose contents are herein incorporated in their entirety by reference.
The foregoing description of the embodiments of the invention has been presented for the purposes of illustration and description. Each and every page of this submission, and all contents thereon, however characterized, identified, or numbered, is considered a substantive part of this application for all purposes, irrespective of form or placement within the application. This specification is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of this disclosure.
This application claims the benefit of U.S. Provisional Application No. 61/434,620, filed Jan. 20, 2011; this application is herein incorporated in its entirety by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61434620 | Jan 2011 | US |
