Method and device for non-contact detection of external electric or magnetic fields
First Claim
1. A sensor for use in a device for non-contact detection of an external field by positioning the sensor at a spot where the external field is to be detected, the sensor comprising a delay line, which is to be exposed contactlessly to action of the external field and comprises:
- a transducer arrangement that is provided on a substrate made of a material capable of transporting therethrough a wave sensitive to said external field, and defines a wave channel for the wave propagation through the substrate exposed to the external field so as to be directly affected by the external field, the transducer arrangement being capable of being actuated by an interrogation signal to generate the wave propagating through the wave channel and capable of converting the wave into an output response signal, said external field affecting a change in a velocity of the wave propagation through the substrate, said output response signal being thereby informative of said external field.
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Abstract
A device for non-contact detection of an external electric or magnetic field is presented. The device comprises an active unit cable of emitting an interrogation signal, and a passive unit to be positioned at a spot where the external field is to be detected. The passive unit comprises a substrate, which is capable of transporting therethrough a wave sensitive to the external field, and is formed with a delay line thereon. The delay line forms a wave channel for the wave'"'"'s propagation, and is capable of converting the interrogation signal into an output response signal. The wave channel is exposed contactlessly to action of the external field, which effects a change in a velocity of the wave propagation through the wave channel, the response output signal being thereby informative of the external field. The active unit is capable of receiving and processing the output response signal for determining and indicating the external field at the spot.
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Citations
39 Claims
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1. A sensor for use in a device for non-contact detection of an external field by positioning the sensor at a spot where the external field is to be detected, the sensor comprising a delay line, which is to be exposed contactlessly to action of the external field and comprises:
a transducer arrangement that is provided on a substrate made of a material capable of transporting therethrough a wave sensitive to said external field, and defines a wave channel for the wave propagation through the substrate exposed to the external field so as to be directly affected by the external field, the transducer arrangement being capable of being actuated by an interrogation signal to generate the wave propagating through the wave channel and capable of converting the wave into an output response signal, said external field affecting a change in a velocity of the wave propagation through the substrate, said output response signal being thereby informative of said external field. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 12)
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11. A sensor for use in a device for non-contact detection of an external field in the vicinity of an electric wire, the sensor comprising:
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a substrate carrying a delay line formed by a transducer arrangement on the substrate to define a wave channel for the wave propagation through the substrate; and
a field transformer operable to concentrate the external field of a given voltage to thereby produce an increased intensity of the field within the delay line exposed to an increased intensity field in a known proportion, the increased intensity field directly affecting a velocity of the wave propagating within the delay line;
wherein the transducer arrangement is capable of being actuated by an interrogation signal to generate said wave propagating through the wave channel and capable of converting the wave into an output response signal, said wave channel being exposed contactlessly to action of the increased intensity field created by said field transformer and proportional to the external field to be measured, which effects a change in the velocity of the wave propagation through the substrate said output response signal produced by the passive unit bent thereby informative of said external field.
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13. A device for non-contact detection of an external field, comprising:
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active and passive units, wherein the passive unit is to be positioned at a spot where the external field is to be detected, and the active unit is operable to emit an interrogation signal to be received at the passive unit, receive an output response signal coming from the passive unit, and process said output response signal for determining and indicating the external field, the passive unit comprising;
a substrate to be exposed to the external field so as to be directly affected by the external field, the substrate being made of a material capable of transporting therethrough a wave sensitive to said external field, and a delay line provided on said substrate to define a wave channel for the wave propagation through the substrate exposed to the external field, the delay line comprising a transducer arrangement capable of being actuated by said interrogation signal to generate said wave propagating through the wave channel and capable of converting the wave into said output response signal, said wave channel being exposed contactlessly to action of the external field, which effects a change in a velocity of the wave propagation, said output response signal produced by the passive unit being thereby informative of said external field. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 32, 33, 34, 35, 36)
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21. A sensor for sensitive detection or external fields, the sensor being mountable at a spot where an external field is to be detected and comprising:
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a substrate made of a material capable of transporting therethrough a wave sensitive to said external field, a first delay line provided on said substrate to form a first wave channel for said wave'"'"'s propagation contactlessly exposed to action of the external field, said first delay line comprising a first transducer arrangement capable of being actuated by a certain interrogation signal to generate said wave propagating through the first wave channel and capable of converting the wave into a first output signal; and
a second delay line provided on said substrate to form a second wave channel for said wave'"'"'s propagation, said second delay line comprising a second transducer arrangement capable of being actuated by a certain interrogation signal to generate the wave propagating through the second wave channel and capable of converting said wave into a second output signal;
wherein said second wave channel is screened from the external field and has the length differing from that of the first wave channel to ensure a phase shift between the first output signal and the second output signal;
the first and the second delay lines of said sensor are connected in parallel to provide an output response signal formed by superposition of said first and second output signals and being thereby informative of the external field. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
said first delay line comprising a first pair of transducers placed on a surface of said substrate and forming therebetween said first wave channel constituting a first acoustic channel, said transducers being capable of launching a SAW into said first channel in response to an input electromagnetic signal and converting the SAW into a first output electromagnetic signal;
said second delay line a second pair of transducers placed on a surface of said substrate and forming therebetween said second wave channel constituting a second acoustic channel, said second pair of transducers being capable of launching SAW into said second channel in response to said input electromagnetic signal and converting the SAW into a second output electromagnetic signal;
thereby, owing to the difference in lengths of said first and said second acoustic channels, the phase of the response signal formed by superposition of said first and said second output signals is indicative of the external electric field.
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27. The sensor according to claim 26, wherein the difference in length between the two acoustic channels is equal to a quarter of the SAW wavelength in the second channel.
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28. The sensor according to claim 24, wherein said electrostriction substrate bears:
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said first delay lime comprising a first pair of transducers placed on a surface of said substrate and forming therebetween said first wave channel constituting a first acoustic channel, said transducers being capable of launching a SAW into said first channel In response to an input electromagnetic signal and converting the SAW into a first output electromagnetic signal;
said second delay lime a second pair of transducers placed on a surface of said substrate and forming therebetween said second wave channel constituting a second acoustic channel, said second pair of transducers being capable of launching SAW into said second channel in response to said input electromagnetic signal and converting the SAW into a second output electromagnetic signal;
thereby, owing to the difference in lengths of said first and said second acoustic channels, the phase of the response signal formed by superposition of said first and said second output signals is indicative of the external electric field.
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29. The sensor according to claim 28, wherein the difference in length between the two acoustic channels is equal to a quarter of the SAW wavelength in the second channel.
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30. The sensor according to claim 21, wherein all said transducers are narrow band transducers.
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31. The sensor according to claim 21, wherein said first pair of the transducers is identical to said second pair of the transducers, and wherein one transducer from each pair is capable of processing a phase coded signal and the other transducer converts a signal without changing its envelope.
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37. A sensor for use in a device for non-contact detection of an external field by positioning the sensor at a spot where the external field is to be detected, the sensor comprising:
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a delay line, which is to be exposed contactlessly to action of the external field, said delay being formed by a transducer arrangement that is provided on a substrate made of a material capable of transporting therethrough a wave sensitive to said external field, and that defines a wave channel for the wave propagation through the substrate, the transducer arrangement being capable of being actuated by an interrogation signal to generate said wave propagating through the wave channel and capable of converting the wave into an output response signal, said external field directly affecting a change in a velocity of the wave propagation, said output response signal being thereby informative of said external field; and
an additional delay line formed by an additional transducer arrangement defining an additional wave channel, wherein said additional wave channel is screened from the external field, and has a propagation length different from that of the other wave channel, said output response signal being a vector sum of output signals of the two wave channels.
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38. A sensor for use in a device for non-contact detection of an external field by positioning the sensor at a spot where the external field is to be detected, the sensor comprising:
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a delay line, which is to be exposed contactlessly to action of the external field and is formed by a transducer arrangement that is provided on a substrate made of a material capable of transporting therethrough a wave sensitive to said external field, and defines a wave channel for the wave propagation through the substrate, the transducer arrangement being capable of being actuated by an interrogation signal to generate said wave propagating through the wave channel and capable of converting the wave into an output response signal, said external field affecting a change in a velocity of the wave propagation, said output response signal being thereby informative of said external field; and
a field transformer operable to increase intensity of a field directly affecting the velocity of the wave propagation within the channel, as compared to the external field intensity, according to a known proportion, said field transformer being composed of two capacitors of different values of a capacity and a distance between the capacitor plates, such that the capacitor of a smaller capacity has a smaller distance between its plates, as compared to the other capacitor, the two capacitors being connected in parallel and being mounted at said spot where the external field is to be detected, the capacitor of the smaller capacity enclosing said delay line in a dielectric space between its place, the inner field of said capacitor of the smaller capacity affecting the velocity of the wave propagation through the channel.
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39. A sensor for use in a device for non-contact detection of an external field by positioning the sensor at a spot where the external field is to be detected, the sensor comprising:
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a delay line, which is to be exposed contactlessly to action of the external field and is formed by a transducer arrangement that is provided on a substrate made of a material capable of transporting therethrough a wave sensitive to said external field, and defines a wave channel for the wave propagation through the substrate, the transducer arrangement being capable of being actuated by an interrogation signal to generate said wave propagating through the wave channel and capable of converting the wave into an output response signal, said external field affecting a change in a velocity of the wave propagation, said output response signal being thereby informative of said external field; and
a field transformer operable to increase intensity of a field directly affecting the velocity of the wave propagation within the channel, as compared to the external field intensity, according to a known proportion, said held transformer comprising a metal element having a part thereof formed with a sharp edge, the field transformer serving as a concentrator of the external field, which is to be detected, within the delay line, when said metal plate is located in said spot so as to extend predominantly along the external field, and said sharp edge is located in the close vicinity of the delay line.
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Specification