US3995222A
Expired / Lapsed
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Sinusoidal waveform generator
Assignee: Sharp Corp
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Filing: 1975-11-19
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Granted: 1976-11-30
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Expires: 1995-11-19
Abstract
Abstract In obtaining a sinusoidal waveform signal of a predetermined frequency, a rectangular waveform signal having a frequency four times higher than the pedetermined frequency of the sinusoidal waveform signal is provided and then subjected to frequency divisions of 1/2 and 1/4 through the use of a couple of binary counters. While the original rectangular waveform signal and the 1/2 frequency divided rectangular waveform signal are both passed through an EXCLUSIVE OR circuit, the 1/2 frequency divided and 1/4 frequency divided rectangular waveform signals are passed through another EXCLUSIVE OR circuit. Both of the outputs of the EXCLUSIVE OR circuits are added to develop a desired step waveform signal, after being evaluated at different weights. The generation of the predetermined sinusoidal waveform signal is achieved by filtering the thus obtained step waveform signal.
Inventors
- 👤 Akira Mitarai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 16:53
CPC Classifications
H; H03; H03B; H03B28/00; H03K; H03K3/00; H03K3/02; H03B1/00; H03B1/04; H03B2200/00; H03B2200/003; H03B2200/0046; H03B2200/006; H03B2200/0064
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
128 words
A sinusoidal waveform generator comprising: a source of rectangular reference pulses of which the frequency is an integer multiple of the frequency of a sinusoidal waveform signal to be generated; means for frequency dividing the rectangular reference pulses by 2; means for frequency dividing the rectangular reference pulses by 4; an EXCLUSIVE OR gate responsive to both of the reference pulses and the 1/2 frequency divided pulses; an EXCLUSIVE OR gate responsive to both of the 1/2 frequency divided pulses and the 1/4 frequency divided pulses; means for effecting addition of both outputs of the EXCLUSIVE OR gates after both are weighed at different magnifying factors to thereby provide a desired step waveform signal; and means for filtering the step waveform signal thereby providing the sinusoidal waveform signal.
Claim 2
Dependent Claim
128 words
A sinusoidal waveform generator comprising: a source of rectangular reference pulses of which the frequency is an integer multiple of the frequency of a sinusoidal waveform signal to be generated; means for frequency dividing the rectangular reference pulses by 2; means for frequency dividing the rectangular reference pulses by 4; an EXCLUSIVE OR gate responsive to both of the reference pulses and the 1/2 frequency divided pulses; an EXCLUSIVE OR gate responsive to both of the 1/2 frequency divided pulses and the 1/4 frequency divided pulses; means for effecting addition of both outputs of the EXCLUSIVE OR gates after both are weighed at different magnifying factors to thereby provide a desired step waveform signal; and means for filtering the step waveform signal thereby providing the sinusoidal waveform signal.
Claim 3
Dependent Claim
30 words
A sinusoidal waveform generator as defined in claim 1 wherein the frequency of the rectangular reference pulses is four times higher than the predetermined frequency of the sinusoidal waveform signal.
Claim 4
Dependent Claim
38 words
A sinusoidal waveform generator as defined in claim 1 further comprising a 1/2 frequency divider for frequency dividing the rectangular reference pulses of which the frequency is eight times higher than the frequency of the sinusoidal waveform signal.
Claim 5
Dependent Claim
19 words
A sinusoidal waveform generator as defined in claim 1 wherein the respective frequency dividing means includes a binary counter.
Claim 6
Dependent Claim
19 words
A sinusoidal waveform generator as defined in claim 4 wherein the binary counter is implemented with integrated circuit technology.
Claim 7
Dependent Claim
40 words
A sinusoidal waveform generator as defined in claim 1 wherein the weighing means includes a couple of resistors operatively associated with the EXCLUSIVE OR gates, the resistance values of the respective resistors being chosen at 1 : 1 + √2.
Claim 8
Dependent Claim
22 words
A sinusoidal waveform generator as defined in claim 1 wherein the adding means includes an operational amplifier implemented with integrated circuit technology.
Claim 9
Dependent Claim
28 words
A sinusoidal waveform generator as defined in claim 1 wherein the filtering means serves to remove the seventh and higher harmonic components included within the step waveform signal.
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) | 1979-11-30 | 1980-05-31 | 1980-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-30 | 1984-05-31 | 1984-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-30 | 1988-05-31 | 1988-11-30 | $7700.00 | Window Closed / Lapsed |