US4727360A
Expired / Lapsed
US
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Frequency-dividing transponder and use thereof in a presence detection system
Assignee: Sensormatic Electronics Corp
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Filing: 1986-07-31
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Granted: 1988-02-23
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Expires: 2006-07-31
Abstract
Abstract A batteryless, portable, transponder useful in a tag for a presence detection system. The transponder detects electromagnetic radiation at a first predetermined frequency and responds to said detection by transmitting electromagnetic radiation at a second frequency that is a subharmonic of the first frequency. The transponder includes an amorphous magnetic material component for storing energy from the electromagnetic radiation detected at the first frequency for transmission as the electromagnetic radiation transmitted at the second frequency. In one embodiment the transponder includes a thin, flat ribbon of low coercivity magnetostrictive amorphous magnetic material having a transverse uniaxial magnetic anisotropy defining a magnetomechanical resonant frequency "f" in accordance with the dimensions of the ribbon, when in the presence of a magnetic bias field of a predetermined intensity, wherein the ribbon responds to the detection of electromagnetic radiation having a frequency "2f" by transmitting electromagnetic radiation at a subharmonic of the frequency "2f"; and means for biasing the ribbon with the predetermined magnetic bias field. In another embodiment, the transponder consists of a single resonant circuit including a nonlinear inductor having a core made of amorphous magnetic material; and a capacitance connected in series with the inductor to define the resonant circuit. The core of the nonlinear inductor includes an elongated thin, flat ribbon of low coercivity amorphous mangetic material. It has been observed that this resonant circuit exhibits a bifurcated frequency-division characteristic in relation to the amplitude of the detected electromagnetic radiation at the first predetermined frequency, whereby additional frequency divisions occur as the amplitude is increased. A coded tag includes two amorphous magnetic material transponders that detect electromagnetic radiation at different frequencies.
Inventors
- 👤 Lucian G. Ferguson
- 👤 Lincoln H. Charlot, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:53
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/22; G08B13/24; G08B13/2402; G08B13/2405; G08B13/2408; G08B13/2411; G01; G01S; G01S13/00; G01S13/74; G01S13/75; G01S13/751; G01S13/753; G06; G06K; G06K7/00; G06K7/10; G06K7/10009; G08B13/2428; G08B13/2431; G08B13/2437; G08B13/2442
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
63 words
A batteryless, portable, transponder for detecting electromagnetic radiation at a first predetermined frequency and responding to said detection by transmitting electromagnetic radiation at a second frequency that is a subharmonic of the first frequency, comprising an amorphous magnetic material component for storing energy from the electromagnetic radiation detected at the first frequency for transmission as the electromagnetic radiation transmitted at the second frequency.
Claim 2
Dependent Claim
63 words
A batteryless, portable, transponder for detecting electromagnetic radiation at a first predetermined frequency and responding to said detection by transmitting electromagnetic radiation at a second frequency that is a subharmonic of the first frequency, comprising an amorphous magnetic material component for storing energy from the electromagnetic radiation detected at the first frequency for transmission as the electromagnetic radiation transmitted at the second frequency.
Claim 3
Dependent Claim
88 words
A transponder according to claim 1, comprising a thin, flat ribbon of low coercivity magnetostrictive amorphous magnetic material having a transverse uniaxial magnetic anisotropy defining a magnetomechanical resonant frequency "f" in accordance with the dimensions of the ribbon, when in the presence of a magnetic bias field of a predetermined intesity, wherein the ribbon responds to the detection of electromagnetic radiation having a frequency "2f" by transmitting electromagnetic radiation at a subharmonic of the frequency "2f"; and means for biasing the ribbon with said predetermined magnetic bias field.
Claim 4
Dependent Claim
64 words
A transponder according to claim 2, wherein the amorphous magnetic material of the ribbon is selected from a group consisting of Fe 67 Co 18 B 14 Si 1 , Fe 81 B 13 .5 Si 3 .5 C 2 , Fe 40 Ni 38 Mo 4 B 18 , Fe 82 B 12 Si 6 and Fe 78 B 13 Si 19 .
Claim 5
Dependent Claim
38 words
A transponder according to claim 2, further comprising a housing defining a cavity that contains the ribbon and enables the ribbon to vibrate freely within the cavity without any restriction being impressed on the ribbon by the housing.
Claim 6
Dependent Claim
36 words
A transponder according to claim 4, wherein the housing further contains the biasing means and disposes the biasing means in a predetermined relationship to the ribbon to bias the ribbon with said predetermined magnetic bias field.
Claim 7
Dependent Claim
161 words
A transponder according to claim 1, comprising a pair of thin, flat ribbons of low coercivity magnetostrictive amorphous magnetic material, each ribbon having a transverse uniaxial magnetic anistropy defining a magnetomechanical resonant frequency "f" in accordance with the dimensions of the ribbon, when in the presence of a magnetic bias field of a predetermined intensity, wherein the ribbon responds to the detection of electromagnetic radiation having a frequency "2f" by transmitting electromagnetic radiation at a subharmonic of the frequency "2f"; a housing defining a plurality of cavities that contain the respective ribbons and enable the ribbons to vibrate freely within the cavities without any restrictions being impressed on the ribbons by the housing; and biasing means contained by the housing and disposed in relation to the ribbons to so magnetically bias the ribbons as to bias at least one of the ribbons with said predetermined magnetic bias field notwithstanding the orientation of the transponder with respect to the Earth's magnetic field.
Claim 8
Dependent Claim
145 words
A coded tag for attachment to an article to be detected within a surveillance zone, comprising a first batteryless, portable, transponder for detecting electromagnetic radiation at a first predetermined frequency and responding to said detection by transmitting electromagnetic radiation at a second frequency that is a subharmonic of the first frequency, including an amorphous magnetic material component for storing energy from the electromagnetic radiation detected at the first frequency for transmission as the electromagnetic radiation transmitted at the second frequency; and a second batteryless, portable, transponder for detecting electromagnetic radiation at a third predetermined frequency and responding to said detection by transmitting electromagnetic radiation at a fourth frequency that is a subharmonic of the third frequency, including an amorphous magnetic material component for storing energy from the electromagnetic radiation detected at the third frequency for transmission as the electromagnetic radiation transmitted at the fourth frequency.
Claim 9
Dependent Claim
145 words
A coded tag for attachment to an article to be detected within a surveillance zone, comprising a first batteryless, portable, transponder for detecting electromagnetic radiation at a first predetermined frequency and responding to said detection by transmitting electromagnetic radiation at a second frequency that is a subharmonic of the first frequency, including an amorphous magnetic material component for storing energy from the electromagnetic radiation detected at the first frequency for transmission as the electromagnetic radiation transmitted at the second frequency; and a second batteryless, portable, transponder for detecting electromagnetic radiation at a third predetermined frequency and responding to said detection by transmitting electromagnetic radiation at a fourth frequency that is a subharmonic of the third frequency, including an amorphous magnetic material component for storing energy from the electromagnetic radiation detected at the third frequency for transmission as the electromagnetic radiation transmitted at the fourth frequency.
Claim 10
Dependent Claim
202 words
A coded tag according to claim 7, wherein the first transponder comprises a first thin, flat ribbon of low coercivity magnetostrictive amorphous magnetic material having a transverse uniaxial magnetic anisotropy defining a first magnetomechanical resonant frequency "f 1 " in accordance with the dimensions of the ribbon, when in the presence of a magnetic bias field of a predetermined intensity, wherein the first ribbon responds to the detection of electromagnetic radiation having a frequency "2f 1 " by transmitting electromagnetic radiation at a subharmonic of the frequency "2f 1 "; and means for biasing the first ribbon with said first predetermined magnetic bias field; and the second transponder comprises a second thin, flat ribbon of low coercivity magnetostrictive amorphous magnetic material having a transverse uniaxial magnetic anisotropy defining a second magnetomechanical resonant frequency resonant frequency "f 2 " in accordance with the dimensions of the ribbon when the presence of a magnetic bias field of a predetermined intensity, wherein the second ribbon responds to the detection of electromagnetic radiation having a frequency "2f 2 " by transmitting electromagnetic radiation at a subharmonic of the frequency "2f 2 "; and means for biasing the second ribbon with said second predetermined magnetic bias field.
Claim 11
Dependent Claim
65 words
A coded tag according to claim 8, wherein the amorphous magnetic material of the ribbons is selected from a group consisting of Fe 67 Co 18 B 14 Si 1 , Fe 81 B 13 .5 Si 3 .5 C 2 , Fe 40 Ni 38 Mo 4 B 18 , Fe 82 B 12 Si 6 and Fe 78 B 13 Si 19 .
Claim 12
Dependent Claim
38 words
A coded tag according to claim 8, further comprising a housing defining cavities that contain the ribbons and enable the ribbons to vibrate freely within the cavities without any restrictions being impressed on the ribbons by the housing.
Claim 13
Dependent Claim
37 words
A coded tag according to claim 10, wherein the housing further contains the biasing means and disposes the biasing means in a predetermined relationship to the ribbons to bias the ribbons with said predetermined magnetic bias field.
Claim 14
Dependent Claim
217 words
A coded tag according to claim 7, comprising a pair of thin, flat ribbons of low coercivity magnetostrictive amorphous magnetic material, the first ribbon having a transverse uniaxial magnetic anisotropy defining a first magnetomechanical resonant frequency "f 1 " in accordance with the dimensions of the ribbon, when in the presence of a magnetic bias field of a predetermined intensity, wherein the first ribbon responds to the detection of electromagnetic radiation having a frequency "2f 1 " by transmitting electromagnetic radiation at a subharmonic of the frequency "2f 1 ", and the second ribbon having a transverse uniaxial magnetic anisotropy defining a second magnetomechanical resonant frequency "f 2 " in accordance with the dimensions of the ribbon, when in the presence of a magnetic bias field of a predetermined intensity, wherein the second ribbon responds to the detection of electromagnetic radiation having a frequency "2f 2 " by transmitting electromagnetic radiation at a subharmonic of the frequency "2f 2 "; a housing defining a plurality of cavities that contain the respective ribbons and enable the ribbons to vibrate freely within the cavities without any restriction being impressed on the ribbons by the housing; and biasing means contained by the housing and disposed in relation to the ribbons to bias the ribbons with said predetermined magnetic bias field.
Claim 15
Dependent Claim
115 words
A presence detection system, comprising means for transmitting an electromagnetic radiation signal of a first predetermined frequency into a surveillance zone; a tag for attachment to an article to be detected within the surveillance zone, including a batteryless, portable, transponder for detecting electromagnetic radiation at the first predetermined frequency and responding to said detection by transmitting electromagnetic radiation at a second frequency that is a subharmonic of the first frequency, said transponder including an amorphous magnetic material component for storing energy from the electromagnetic radiation detected at the first frequency for transmission as the electromagnetic radiation transmitted at the second frequency; and means for detecting electromagnetic radiation at the second frequency within the surveillance zone.
Claim 16
Dependent Claim
115 words
A presence detection system, comprising means for transmitting an electromagnetic radiation signal of a first predetermined frequency into a surveillance zone; a tag for attachment to an article to be detected within the surveillance zone, including a batteryless, portable, transponder for detecting electromagnetic radiation at the first predetermined frequency and responding to said detection by transmitting electromagnetic radiation at a second frequency that is a subharmonic of the first frequency, said transponder including an amorphous magnetic material component for storing energy from the electromagnetic radiation detected at the first frequency for transmission as the electromagnetic radiation transmitted at the second frequency; and means for detecting electromagnetic radiation at the second frequency within the surveillance zone.
Claim 17
Dependent Claim
91 words
A system according to claim 13, wherein the transponder comprises a thin, flat ribbon of low coercivity magnetostrictive amorphous magnetic material having a transverse uniaxial magnetic anisotropy defining a magnetomechanical resonant frequency "f" in accordance with the dimensions of the ribbon, when in the presence of a magnetic bias field of a predetermined intensity, wherein the ribbon responds to the detection of electromagnetic radiation having a frequency "2f" by transmitting electromagnetic radiation at a subharmonic of the frequency "2f"; and means for biasing the ribbon with said predetermined magnetic bias field.
Claim 18
Dependent Claim
64 words
A system according to claim 14, wherein the amorphous magnetic material of the ribbons is selected from a group consisting of Fe 67 Co 18 B 14 Si 1 , Fe 81 B 13 .5 Si 3 .5 C 2 , Fe 40 Ni 38 Mo 4 B 18 , Fe 82 B 12 Si 6 and Fe 78 B 13 Si 19 .
Claim 19
Dependent Claim
41 words
A system according to claim 14, wherein the transponder further comprises a housing defining a cavity that contains the ribbon and enables the ribbon to vibrate freely within the cavity without any restriction being impressed on the ribbon by the housing.
Claim 20
Dependent Claim
36 words
A system according to claim 16, wherein the housing further contain the biasing means and disposes the biasing means in a predetermined relationship to the ribbon to bias the ribbon with said predetermined magnetic bias field.
Claim 21
Dependent Claim
164 words
A system according to claim 13, wherein the transponder comprises a pair of thin, flat ribbons of low coercivity magnetostrictive amorphous magnetic material, each ribbon having a transverse uniaxial magnetic anisotropy defining a magnetomechanical resonant frequency "f" in accordance with the dimensions of the ribbon, when in the presence of a magnetic bias field of a predetermined intensity, wherein the ribbon responds to the detection of electromagnetic radiation having a frequency "2f" by transmitting electromagnetic radiation at a subharmonic of the frequency "2f"; a housing defining a plurality of cavities that contain the respective ribbons and enable the ribbons to vibrate freely within the cavities without any restriction being impressed on the ribbons by the housing; and biasing means contained by the housing and disposed in relation to the ribbons to so magnetically bias the ribbons as to bias at least one of the ribbons with said predetermined magnetic bias field notwithstanding the orientation of the transponder with respect to the Earth's magnetic field.
Claim 22
Dependent Claim
143 words
A system according to claim 13, wherein the tag is a coded tag comprising a first batteryless, portable transponder for detecting electromagnetic radiation at a first predetermined frequency and responding to said detection by transmitting electromagnetic radiation at a second frequency that is a subharmonic of the first frequency, including an amorphous magnetic material component for storing energy from the electromagnetic radiation detected at the first frequency for transmission as the electromagnetic radiation transmitted at the second frequency; and a second batteryless, portable transponder for detecting electromagnetic radiation at a third predetermined frequency and responding to said detection by transmitting electromagnetic radiation at a fourth frequency that is a subharmonic of the third frequency, including an amorphous magnetic material component for storing energy from the electromagnetic radiation detected at the third frequency for transmission as the electromagnetic radiation transmitted at the fourth frequency.
Claim 23
Dependent Claim
200 words
A system according to claim 19, wherein the first transponder comprises a first thin, flat ribbon of low coercivity magnetostrictive amorphous magnetic material having a transverse uniaxial magnetic anistropy defining a first magnomechanical resonant frequency "f 1 " in accordance with the dimensions of the ribbon, when in the presence of a magnetic bias field of a predetermined intensity, wherein the first ribbon responds to the detection of electromagnetic radiation having a frequency of "2f 1 " by transmitting electromagnetic radiation at a subharmonic of the frequency "2f 1 "; and means for biasing the first ribbon with said predetermined magnetic bias field; and the second transponder comprises a second thin, flat ribbon of low coercivity magnetostrictive amorphous magnetic material having a transverse uniaxial magnetic anistropy defining a second magnomechanical resonant frequency "f 2 " in accordance with the dimensions of the ribbon, when in the presence of a magnetic bias field of a predetermined intensity, wherein the second ribbon responds to the detection of electromagnetic radiation having a frequency of "2f 2 " by transmitting electromagnetic radiation at a subharmonic of the frequency "2f 2 "; and means for biasing the second ribbon with said predetermined magnetic bias field.
References Cited (Backward Citations)
US4314373A
Cited
GB2017454A
Cited
US4298862A
Cited
US4484184A
Cited
US4481428A
Cited
US4495487A
Cited
US4510490A
Cited
US4510489A
Cited
US4553136A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-02-22 | 1991-08-24 | 1992-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-22 | 1995-08-24 | 1996-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-22 | 1999-08-24 | 2000-02-23 | $7700.00 | Window Closed / Lapsed |