US3921084A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wideband coherent F M detector
Assignee: R F L IND Inc
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Filing: 1974-07-31
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Granted: 1975-11-18
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Expires: 1994-07-31
Abstract
Abstract An FM detector comprising integrators, differentiators, summers and multipliers arranged in two sections. One section functions as a wideband, coherent FM discriminator and the other section functions as a low-delay carrier suppressor. All of the components are compatible with integrated circuit technology.
Inventors
- 👤 Rd Edward J A Kratt
- 👤 Jacob Klapper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:15
CPC Classifications
H; H03; H03D; H03D3/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
143 words
Apparatus for demodulating a frequency modulated carrier wave, which apparatus comprises, a. a first network comprising a first differentiator receiving the said wave and producing a first output and a second differentiator receiving the first output and producing a second output, said second output and the input to said first differentiator being of substantially opposite polarity and having amplitudes which cross at a predetermined frequency, b. circuit elements applying the said second output and the input to said first differentiator to a first summer producing substantially a zero output at the said predetermined frequency, c. a first coherent amplitude detector having two inputs, and d. circuit elements applying the output of said summer to one input of said detector, the other input to said detector being derived from the input to said first differeNtiator, the output of said detector being the demodulated wave.
Claim 2
Dependent Claim
143 words
Apparatus for demodulating a frequency modulated carrier wave, which apparatus comprises, a. a first network comprising a first differentiator receiving the said wave and producing a first output and a second differentiator receiving the first output and producing a second output, said second output and the input to said first differentiator being of substantially opposite polarity and having amplitudes which cross at a predetermined frequency, b. circuit elements applying the said second output and the input to said first differentiator to a first summer producing substantially a zero output at the said predetermined frequency, c. a first coherent amplitude detector having two inputs, and d. circuit elements applying the output of said summer to one input of said detector, the other input to said detector being derived from the input to said first differeNtiator, the output of said detector being the demodulated wave.
Claim 3
Dependent Claim
54 words
Apparatus as recited in claim 1, including means adding to the output of one of said differentiators a portion of its input, which portion has an amplitude and phase to cancel the component appearing in the input to said first summer, which component is in quadrature with the input to the said first network.
Claim 4
Dependent Claim
101 words
Apparatus as recited in claim 1, including a second network comprising an integrator, a second coherent amplitude detector and a second summer, said integrator receiving an input derived from the output of said first summer, said second detector receiving a first input derived from the output of said integrator and a second input derived from the output of said first differentiator, said second summer receiving a first input derived from the output of said first detector and a second input derived from the output of said second detector, the output of said second summer being the difference between its two inputs.
Claim 5
Dependent Claim
52 words
Apparatus as recited in claim 3, including means adding to the output of one of said differentiators a portion of its input, which portion has an amplitude and phase to cancel the component appearing in the said second output and which is in quadrature with the input to the said first network.
Claim 6
Dependent Claim
47 words
Apparatus as recited in claim 4, including means adding to the output of said integrator a portion of its input, which portion is 180* out of phase with and equal in amplitude to the component of the output of said integrator which is collinear with its input.
Claim 7
Dependent Claim
94 words
Apparatus as recited in claim 1, including first means adding to the output of said first differentiator a portion of its input, which portion is 180* out of phase with and equal in amplitude to the component in the output of said first differentiator which is collinear with its input; and second means adding to the output of said second differentiator a portion of its input, which portion is 180* out of phase with and equal in amplitude to the component in the output of said second differentiator which is collinear with its input.
Claim 8
Dependent Claim
80 words
Apparatus as recited in claim 1, wherein the said predetermined frequency is different from the center frequency of the modulated carrier wave resulting in a d.c. component in the output of said first detector and including a second summer having two inputs, the first input to said second summer being the output of said first detector and the second input to said second summer being a d.c. voltage having a polarity and magnitude to substantially cancel the said d.c. component.
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) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |