US4063199A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radio frequency pulse width amplitude modulation system
Assignee: RCA Corp
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Filing: 1977-02-10
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Granted: 1977-12-13
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Expires: 1997-02-10
Abstract
Abstract Amplitude modulation of a radio frequency carrier is achieved by generating a rectangular wave pulse train at the carrier frequency, the pulses of which vary in width as a function of the amplitude of the audio input signal. The audio frequency input wave is subjected to an arc sine conversion process prior to the generation of the rectangular wave pulse train. The radio frequency pulse width modulated wave is amplified and then filtered to pass the fundamental radio frequency voltage and its modulation side bands.
Inventors
- 👤 Leonard Lewis Oursler, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:32
CPC Classifications
H; H03; H03C; H03C1/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
129 words
A system for amplitude modulating a carrier frequency signal in accordance with a modulating signal having a maximum frequency of f m , said system comprising: converting means responsive to said signal for generating an output signal which is the arc sine of said modulating signal: carrier generator means for generating a carrier signal having a substantially triangular waveform at said carrier frequency f c ; pulse width modulation means responsive to said carrier signal and said converting means output signal for generating a pulse width modulated signal, band pass filtering means responsive to said pulse width modulated signal for passing only signals from f c - f m to f c + f m with low attenuation whereby said carrier frequency is amplitude modulated by said modulating signal.
Claim 2
Independent Claim
129 words
A system for amplitude modulating a carrier frequency signal in accordance with a modulating signal having a maximum frequency of f m , said system comprising: converting means responsive to said signal for generating an output signal which is the arc sine of said modulating signal: carrier generator means for generating a carrier signal having a substantially triangular waveform at said carrier frequency f c ; pulse width modulation means responsive to said carrier signal and said converting means output signal for generating a pulse width modulated signal, band pass filtering means responsive to said pulse width modulated signal for passing only signals from f c - f m to f c + f m with low attenuation whereby said carrier frequency is amplitude modulated by said modulating signal.
Claim 3
Dependent Claim
63 words
The system according to claim 1 wherein said carrier generator means further includes: oscillation means for generating a signal having a sinusoidal waveform at said carrier frequency, square wave generator means responsive to said sinusoidal signal for generating a signal having a substantially square waveform at said carrier frequency, and integrating means responsive to said substantially square signal for generating said triangular signal.
Claim 4
Dependent Claim
26 words
The system according to claim 2 wherein said square wave generator means further includes adjustable means for varying the duty cycle of said substantially square signal.
Claim 5
Dependent Claim
63 words
The system according to claim 1 further including: negative feedback means responsive to said amplitude modulated signal at the output of said filtering means for generating a low level feedback having a waveform which is substantially the phase inverted shape of the modulated envelope of said amplitude modulated signal, and means for applying said feedback signal to the input of said converting means.
Claim 6
Dependent Claim
26 words
The system according to claim 1 including amplifier means coupled to said pulse width modulation means for increasing the magnitude of said pulse width modulated signal.
References Cited (Backward Citations)
US3363199A
Cited
US3506920A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-12-12 | 1981-06-13 | 1981-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-12 | 1985-06-13 | 1985-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-12 | 1989-06-13 | 1989-12-13 | $7700.00 | Window Closed / Lapsed |