US3771044A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Broad band frequency doubler and limiter utilizing magneto-resistive effect in a rotating magnetic field
Assignee: Verizon Laboratories Inc
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Filing: 1973-02-21
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Granted: 1973-11-06
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Expires: 1993-02-21
Abstract
Abstract Apparatus for frequency doubling and limiting over a broad band of frequencies by using a magneto-resistive effect in a magnetic film. The apparatus includes a thin plate of magneto-resistive, ferromagnetic material immersed in an electronically generated rotating magnetic field. In operation, an external source provides a constant DC current through the plate. When a signal at frequency f1 is impressed at the input terminals of the coils generating the rotating magnetic field, a signal at frequency 2 f1 appears at the output terminals of the magneto-resistive element. As the frequency of the input drive signal is changed, the output signal will continuously follow the input signal but at double the frequency without the use of an output filter. The amplitude of the output signal is directly proportional to the magnitude of the impressed DC current and to the magnitude of the spatial magneto-resistance effect in the plate. At sufficiently large input levels, the amplitude of the output signal will remain constant with input signal level. The device is capable of functioning as a frequency doubler and limiter on a frequency range from sub-audio to VHF.
Inventors
- 👤 L Cohen
- 👤 B Shortt
- 👤 M Urban
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:18
CPC Classifications
H; H02; H02M; H02M11/00; H03; H03B; H03B19/00; H03B19/03
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
111 words
The combination comprising: a. a film of ferromagnetic material having anisotropic magnetoresistive properties wherein the resistive value changes dependent on the direction of a magnetic field in the plane of said film; b. first means for causing a flow of electric current in the plane of said film from one edge to another edge of said film; c. second means for producing a magnetic field in the plane of said film; d. third means for rotating said second means causing the resistance of said film to vary; and e. output means electrically connected to said film and responsive to said changes in resistance of said film for producing an output signal.
Claim 2
Dependent Claim
111 words
The combination comprising: a. a film of ferromagnetic material having anisotropic magnetoresistive properties wherein the resistive value changes dependent on the direction of a magnetic field in the plane of said film; b. first means for causing a flow of electric current in the plane of said film from one edge to another edge of said film; c. second means for producing a magnetic field in the plane of said film; d. third means for rotating said second means causing the resistance of said film to vary; and e. output means electrically connected to said film and responsive to said changes in resistance of said film for producing an output signal.
Claim 3
Dependent Claim
118 words
Apparatus for producing a constant amplitude sinusoidal output signal the frequency of which is twice the frequency of an input signal comprising: a. a film of ferromagnetic material having anisotropic magneto-resistive properties; b. first means for causing a flow of electric current in the plane of said film from one edge to another edge of said film; c. second means for producing a magnetic field in the plane of said film; d. third means for rotating said second means causing the resistance of said film to vary producing an output signal at twice the rotation rate; and e. output terminal means for obtaining said output signal so that said output signal may be applied to a utilization device.
Claim 4
Dependent Claim
118 words
Apparatus for producing a constant amplitude sinusoidal output signal the frequency of which is twice the frequency of an input signal comprising: a. a film of ferromagnetic material having anisotropic magneto-resistive properties; b. first means for causing a flow of electric current in the plane of said film from one edge to another edge of said film; c. second means for producing a magnetic field in the plane of said film; d. third means for rotating said second means causing the resistance of said film to vary producing an output signal at twice the rotation rate; and e. output terminal means for obtaining said output signal so that said output signal may be applied to a utilization device.
Claim 5
Dependent Claim
25 words
The apparatus of claim 2 wherein said second means includes two coils of conducting wires wrapped around said film and oriented orthogonal to each other.
Claim 6
Dependent Claim
33 words
The apparatus of claim 3 wherein said third means includes a 90* phase inverter electrically connected between said coils, said phase inverter having input terminals so that an input signal may be applied.
Claim 7
Dependent Claim
11 words
The apparatus of claim 4 wherein said film is a permalloy.
Claim 8
Dependent Claim
17 words
The apparatus of claim 4 wherein the magnetic field strength is between about 5 and 20 gauss.
Claim 9
Dependent Claim
149 words
A frequency doubler comprising: a. a substrate; b. a film of ferromagnetic material positioned on one surface of said substrate, said film having anisotropic magneto-resistive properties; c. first means for causing a flow of electric current in the plane of said film from one edge to another edge of said film; d. two coils of wires wrapped around said film oriented orthogonal to each other, said coils being in space and electrical quadrature; e. a 90* phase inverter electrically connected between said coils; f. input terminals electrically connected to said coils and being adapted to receive an external input signal at frequency f1 for producing a rotating magnetic field in the plane of said film, said magnetic field changing the resistive properties to produce output signal 2f1; and g. output terminal means for obtaining said output signal so that said output signal may be applied to a utilization device.
Claim 10
Dependent Claim
149 words
A frequency doubler comprising: a. a substrate; b. a film of ferromagnetic material positioned on one surface of said substrate, said film having anisotropic magneto-resistive properties; c. first means for causing a flow of electric current in the plane of said film from one edge to another edge of said film; d. two coils of wires wrapped around said film oriented orthogonal to each other, said coils being in space and electrical quadrature; e. a 90* phase inverter electrically connected between said coils; f. input terminals electrically connected to said coils and being adapted to receive an external input signal at frequency f1 for producing a rotating magnetic field in the plane of said film, said magnetic field changing the resistive properties to produce output signal 2f1; and g. output terminal means for obtaining said output signal so that said output signal may be applied to a utilization device.
Claim 11
Dependent Claim
16 words
The apparatus of claim 7 wherein said magnetic field is between about 5 and 20 gauss.
Claim 12
Dependent Claim
10 words
The apparatus of claim 7 wherein said film is permalloy.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-05 | 1977-05-07 | 1977-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-05 | 1981-05-07 | 1981-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-05 | 1985-05-07 | 1985-11-06 | $7700.00 | Window Closed / Lapsed |