US3921083A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wideband coherent FM 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
2026-11-07 08:57
CPC Classifications
H; H03; H03D; H03D3/00
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
128 words
Apparatus for demodulating a frequency modulated carrier wave, which apparatus comprises, a. a first network comprising a first integrator receiving said wave and producing a first output and a first differentiator receiving said wave and producing a second output, the two outputs being of substantially opposite polarity and having different amplitude vs frequency responses which cross at a predetermined frequency, b. circuit elements applying the said two outputs to a first summer producing substantially a zero output at 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 said second output, the output of said detector being a demodulated wave.
Claim 2
Dependent Claim
128 words
Apparatus for demodulating a frequency modulated carrier wave, which apparatus comprises, a. a first network comprising a first integrator receiving said wave and producing a first output and a first differentiator receiving said wave and producing a second output, the two outputs being of substantially opposite polarity and having different amplitude vs frequency responses which cross at a predetermined frequency, b. circuit elements applying the said two outputs to a first summer producing substantially a zero output at 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 said second output, the output of said detector being a demodulated wave.
Claim 3
Dependent Claim
58 words
Apparatus as recited in claim 1, including circuit elements adding to said first summer a portion of the input of the said first network, which portion is 180* out of phase with and equal in amplitude to the algebraic sum of the components of the said two outputs which are collinear with the input to said first network.
Claim 4
Dependent Claim
92 words
Apparatus as recited in claim 1, including a second network comprising a second differentiator, a second coherent amplitude detector and a second summer, said second differentiator receiving a signal derived from said first summer, said second detector receiving one input derived from said second differentiator and a second input derived from the input to said first network, and said second summer receiving a first input derived from said second detector and a second input derived from said first detector, the output of said second summer being the difference between its two inputs.
Claim 5
Dependent Claim
56 words
Apparatus as recited in claim 3, including means applying to said first summer a portion of the input of said first network, which portion is 180* out of phase with and equal in amplitude to the algebraic sum of the components of the said two outputs which are collinear with the input to said first network.
Claim 6
Dependent Claim
49 words
Apparatus as recited in claim 4, including means adding a portion of the input of said second differentiator to its output, which portion is 180* out of phase with and equal in amplitude to the component of the output of said second differentiator which is collinear with its input.
Claim 7
Dependent Claim
59 words
Apparatus as recited in claim 1, including means adding a portion of the input of said first differentiator to its output, which portion is 180* out of phase with and equal in amplitude to the algebraic sum of the components of the outputs of said first integrator and differentiator which are collinear with the input to said first network.
Claim 8
Dependent Claim
59 words
Apparatus as recited in claim 1, including means adding a portion of the input of said first integrator to its output, which portion is 180* out of phase with and equal in amplitude to the algebraic sum of the components of the outputs of said first integrator and differentiator which are collinear with the input to said first network.
Claim 9
Dependent Claim
31 words
Apparatus as recited in claim 1, wherein the said other input to said first detector is derived from the difference between the outputs of said first integrator and said first differentiator.
Claim 10
Dependent Claim
56 words
Apparatus as recited in claim 8, including means adding to said first summer a portion of the input of said first network, which portion is 180* out of phase with and equal in amplitude to the algebraic sum of the components of the said two outputs which are collinear with the input to said first network.
Claim 11
Dependent Claim
116 words
Apparatus as recited in claim 8, including a second network comprising a second integrator, a second differentiator, a second coherent amplitude detector and a second summer, said second integrator and second differentiator receiving an output derived from the output of said first summer, said second detector receiving a first input derived from the difference between the outputs of said second integrator and second differentiator and a second input derived from the input to said first network, and second summer receiving a first input derived from the output of said second detector and a second input derived from the output of said first detector, the output of said second summer being the sum of its two inputs.
Claim 12
Dependent Claim
52 words
Apparatus as recited in claim 10, including means adding to said first summer a portion of the input of said first network, which portion is 180* out of phase with and equal in amplitude to the components of the said two outputs which are collinear with the input to said first network.
Claim 13
Dependent Claim
60 words
Apparatus as recited in claim 11, including means adding to the said first input of the second detector a portion of the output of said first summer, which portioN is 180* out of phase with and equal in amplitude to the first component of said input to the second detector which is collinear with the output of said first summer.
Claim 14
Dependent Claim
66 words
Apparatus as recited in claim 8, including means adding to the said other input of said first detector a portion of the input of the said first network, which portion is 180* out of phase with and equal in amplitude to the component which is the algebraic difference of the said first and second outputs and which is collinear with the input to said first network.
Claim 15
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 |