US3898573A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Voltage controlled non-linear filter
Assignee: Individual
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Filing: 1973-12-07
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Granted: 1975-08-05
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Expires: 1993-12-07
Abstract
Abstract A voltage controlled non-linear filter for high and low frequency signals comprises means for separating and dissipating the high frequency out-of-band energy and passing the low freqeuncy in-band energy. The filtering in a low-pass filter is achieved without phase shift both in- and out-of-band by use of conjugate high- and low-pass filters located before and after the dissipating means, respectively. A hard clipper is used to perform the dissipating function, and its reference clipping level is provided so that the maximum amplitude of the in-band signal arriving at the input to the clipper is slightly less than the clipping level. The output of the low-pass filter may be fed back to set the clipping level so that this level can track the in-band signal amplitude. The clipping level may also be controlled by a bias control voltage. A sensing resistor between the clipper and the means to set the clipping level senses the high frequency information and thus, the non-linear filter can serve as a high-pass filter with no phase shift when only the low-pass filter is used after the dissipating means.
Inventors
- 👤 Stanley A Sherman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:23
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/04; H03H11/0405; H03G; H03G11/00; H03G11/02
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
204 words
Apparatus for frequency separation of an electrical wave having low frequency and high frequency components comprising clipping means haviNg an input, an output and a clipping level setting input, said electrical wave being supplied to said input, low-pass filter means having an input and output, said input of said low-pass filter means being connected to said output of said clipping means, first amplifying means having an input and an output, said output of said low pass filter means being connected to said input of said first amplifying means, a bias generating means having an input, an output and a control input, said output of said first amplifying means being connected to said input of said bias generating means, a control voltage being coupled to said control input of said bias generating, said output of said bias generator being connected to said clipping level setting input of said clipping means, said clipping level being set by the superposition of the controlled bias and the low frequency components produced at said output of said low pass filter means to instantaneously set said clipping level responsive to the magnitude of said low frequency components, said clipper separating said high and low frequency components of said electrical wave.
Claim 2
Dependent Claim
204 words
Apparatus for frequency separation of an electrical wave having low frequency and high frequency components comprising clipping means haviNg an input, an output and a clipping level setting input, said electrical wave being supplied to said input, low-pass filter means having an input and output, said input of said low-pass filter means being connected to said output of said clipping means, first amplifying means having an input and an output, said output of said low pass filter means being connected to said input of said first amplifying means, a bias generating means having an input, an output and a control input, said output of said first amplifying means being connected to said input of said bias generating means, a control voltage being coupled to said control input of said bias generating, said output of said bias generator being connected to said clipping level setting input of said clipping means, said clipping level being set by the superposition of the controlled bias and the low frequency components produced at said output of said low pass filter means to instantaneously set said clipping level responsive to the magnitude of said low frequency components, said clipper separating said high and low frequency components of said electrical wave.
Claim 3
Dependent Claim
43 words
Apparatus as set forth in claim 1, comprising high-pass filter means having an input and an output, said input of said high-pass filter means receiving said electrical wave, said output of said high-pass filter means connected to said input of said clipping means.
Claim 4
Dependent Claim
54 words
Apparatus as set forth in claim 1 comprising second amplifying means having an input and an output, said input of said second amplifying means being connected to said output of said bias generating means, and said output of said second amplifying means being connected to said clipping level setting input of said clipping means.
Claim 5
Dependent Claim
78 words
Apparatus as set forth in claim 2 comprising second and third amplifying means each having an input and an output, said input of said bias generating means and said output of said second amplifying means being connected to said clipping level setting input of said clipping means, said input of said third amplifying means connected to said output of said high-pass filter means, said output of said third amplifying means connected to said input of said clipping means.
Claim 6
Dependent Claim
17 words
Apparatus as set forth in claim 4, wherein said first, second, and third amplifying means are wideband.
Claim 7
Dependent Claim
17 words
Apparatus as set forth in claim 4, wherein said first, second, and third amplifying means are linear.
Claim 8
Dependent Claim
16 words
Apparatus as set forth in claim 4, wherein said low-pass and high-pass filter means are conjugate.
Claim 9
Dependent Claim
19 words
Apparatus as set forth in claim 4, wherein said first, second and third amplifier means have low output impedances.
Claim 10
Dependent Claim
15 words
Apparatus as set forth in claim 4, wherein said clipping means is a hard clipper.
Claim 11
Dependent Claim
32 words
Apparatus as set forth in claim 4, wherein the combined amplitude gain between the output of said clipping means and the level setting input of said clipping means is less than unity.
Claim 12
Dependent Claim
23 words
Apparatus as set forth in claim 1, comprising current sensing resistor means connected to said clipping means for sensing the high frequency components.
Claim 13
Dependent Claim
43 words
Apparatus as set forth in claim 11, comprising second amplifier means having an input and output, said output of said second amplifier means being connected to said level sensing input of said clipper through said bias generator and said current sensing resistor means.
Claim 14
Dependent Claim
16 words
Apparatus as set forth in claim 12, wherein said second amplifier means have low output impedances.
Claim 15
Dependent Claim
40 words
Apparatus as set forth in claim 12, comprising a high pass filter having an input and an output, said output connected to said input of said clipper, said electrical wave being coupled to said input of said high pass filter.
Claim 16
Dependent Claim
96 words
For an electrical wave having low frequency and high frequency components, a method of separating said components comprising the steps of controlling a clipping level, clipping said high frequency components while passing said low frequency components, emphasizing said passed low frequency components with respect to any passed hIgh frequency components, and instantaneously tracking the superposition of a controlled bias level and said emphasized passed low frequency components with said clipping level to instaneously set the clipping level in response to the magnitude of low frequency components for separating said high frequency from said low frequency components.
Claim 17
Dependent Claim
96 words
For an electrical wave having low frequency and high frequency components, a method of separating said components comprising the steps of controlling a clipping level, clipping said high frequency components while passing said low frequency components, emphasizing said passed low frequency components with respect to any passed hIgh frequency components, and instantaneously tracking the superposition of a controlled bias level and said emphasized passed low frequency components with said clipping level to instaneously set the clipping level in response to the magnitude of low frequency components for separating said high frequency from said low frequency components.
Claim 18
Dependent Claim
21 words
A method as set forth in claim 15, comprising the step of sensing said high frequency components after said clipping step.
Claim 19
Dependent Claim
22 words
A method as set forth in claim 15, comprising the step of emphasizing said high frequency components prior to said clipping step.
Claim 20
Dependent Claim
42 words
A method as set forth in claim 17, comprising the steps of phase shifting said electrical wave equal and opposite amounts during said steps of emphasizing said high frequency components and emphasizing said passed low frequency components to achieve zero phase shift.
Claim 21
Dependent Claim
21 words
A method as set forth in claim 18, comprising the step of sensing said high frequency components after said clipping step.
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) | 1978-08-04 | 1979-02-03 | 1979-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-04 | 1983-02-03 | 1983-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-04 | 1987-02-03 | 1987-08-05 | $7700.00 | Window Closed / Lapsed |