US3787772A
Expired / Lapsed
US
⏱️ 0.0 years remaining
F. m. transmitter employing magnetically modulated ferrimagnetic resonator
Assignee: RYKA SCIENT Inc
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Filing: 1972-06-05
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Granted: 1974-01-22
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Expires: 1992-06-05
Abstract
Abstract A ferrimagnetic crystal resonator is employed as the frequency determinative element of a radio frequency oscillator. The ferrimagnetic crystal is disposed in the gap of a magnet and the magnetic field is modulated in intensity in accordance with an audio AM signal to be impressed on the carrier. The audio AM modulation of the magnetic field of the magnet is converted into frequency modulation of the carrier frequency of the ferrimagnetic crystal controlled oscillator. An internally generated stable reference radio frequency signal is compared with a sample of the FM output signal to produce an error signal for correcting the average magnetic field intensity for controlling the average or carrier frequency of the FM transmitter.
Inventors
- 👤 J Sedin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:04
CPC Classifications
H; H03; H03C; H03C3/00; H03C3/02; H03C3/09; H03C7/00; H03C7/02; H03C7/022
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
156 words
In a frequency modulation transmitter, magnet means having a gap and providing a magnetic field in said gap, a ferrimagnetic crystal resonator body disposed in the gap of said magnet means, a radio frequency oscillator circuit including transistor means having, base, emitter, and collector terminals, electrical circuit means coupled to said ferrimagnetic crystal resonator body in radio frequency energy exchanging relation therewith for controlling the operating frequency of said radio frequency oscillator circuit, said resonator body being magnetically coupled in circuit with said transistor means, audio frequency circuit means for modulating the intensity of said magnetic field in said gap in accordance with an audio frequency signal to be transmitted for modulating the operating frequency of said radio frequency circuit at the frequency of said audio signal and with a frequency deviation in accordance with the amplitude of said audio signal, and antenna means coupled to said radio frequency circuit means for radiating frequency-modulated radio energy.
Claim 2
Dependent Claim
156 words
In a frequency modulation transmitter, magnet means having a gap and providing a magnetic field in said gap, a ferrimagnetic crystal resonator body disposed in the gap of said magnet means, a radio frequency oscillator circuit including transistor means having, base, emitter, and collector terminals, electrical circuit means coupled to said ferrimagnetic crystal resonator body in radio frequency energy exchanging relation therewith for controlling the operating frequency of said radio frequency oscillator circuit, said resonator body being magnetically coupled in circuit with said transistor means, audio frequency circuit means for modulating the intensity of said magnetic field in said gap in accordance with an audio frequency signal to be transmitted for modulating the operating frequency of said radio frequency circuit at the frequency of said audio signal and with a frequency deviation in accordance with the amplitude of said audio signal, and antenna means coupled to said radio frequency circuit means for radiating frequency-modulated radio energy.
Claim 3
Dependent Claim
70 words
The apparatus of claim 1 including, means for generating a reference radio frequency, means for comparing said frequency modulated radio frequency signal with said reference frequency signal to derive an error signal, and means responsive to said error signal for controlling the average intensity of said magnetic field of said magnet means as applied to said ferrimagnetic resonator body for controlling the average resonant frequency of said ferrimagnetic resonator body.
Claim 4
Dependent Claim
88 words
The apparatus of claim 2 wherein said means for deriving a reference radio frequency includes crystal controlled oscillator means for supplying a reference radio frequency signal, and wherein said means for comparing said reference frequency signal with said frequency modulated radio frequency signal includes mixer means for mixing the reference radio frequency signal with a sample of said frequency modulated radio frequency signal to produce a difference frequency signal, and frequency discriminator means for comparing the difference frequency with a reference difference frequency to derive said error signal.
Claim 5
Dependent Claim
25 words
The apparatus of claim 1 including, microphone means for receiving audio wave energy and for converting same into said audio frequency signal to be transmitted.
Claim 6
Dependent Claim
50 words
The apparatus of claim 2 wherein said means for controlling the average intensity of said magnetic field in accordance with said error signal includes auxilliary electromagnetic coil means carried on said magnet means for superimposing a corrective magnetic field component on the magnetic field in said gap of said magnet.
Claim 7
Dependent Claim
53 words
The apparatus of claim 2 wherein said radio frequency circuit means includes, transistor means having base, emitter and collector terminals connected as a radio frequency oscillator, and wherein said ferrimagnetic crystal resonator body is magnetically coupled in circuit with said transistor means for controlling the operating radio frequency of said radio frequency oscillator.
References Cited (Backward Citations)
US2556226A
Cited
US3102243A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |