US3727147A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Band-pass filter
Assignee: SONEX Inc
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Filing: 1971-04-21
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Granted: 1973-04-10
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Expires: 1991-04-21
Abstract
Abstract A class of band-pass filters are provided, each of which comprises a plurality of low pass active filters. Each of the filters has related resonating frequency and damping characteristics. The resonating frequency and damping characteristics for each of the filters causes all of the poles of the filters to be along a line parallel to the outputs of the filter so that the output signals of the filters are summed with alternate ones of the filters having the output signal inverted with respect to the other of the filters.
Inventors
- 👤 Witt K De
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 05:48
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/04; H03H11/12; H03H11/1217
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
99 words
A band-pass filter comprising a plurality of low pass active filters, each of said filters having related resonating frequency and damping characteristics, said resonating frequency and damping characteristics for each of said filters causing all of the poles of said filters to be along a line parallel to the imaginary axis of the S plane, means connected to the outputs of said filters so that the output signals of said filters are (summed with) combined, the gains of alternate ones of said filters (having the output signal) being inverted with respect to the other of said filters when combined.
Claim 2
Dependent Claim
99 words
A band-pass filter comprising a plurality of low pass active filters, each of said filters having related resonating frequency and damping characteristics, said resonating frequency and damping characteristics for each of said filters causing all of the poles of said filters to be along a line parallel to the imaginary axis of the S plane, means connected to the outputs of said filters so that the output signals of said filters are (summed with) combined, the gains of alternate ones of said filters (having the output signal) being inverted with respect to the other of said filters when combined.
Claim 3
Dependent Claim
155 words
A band-pass filter comprising a plurAlity of low pass active filters, each of said filters having related resonating frequency and damping characteristics, said resonating frequency and damping characteristics for each of said filters causing all of the poles of said filters to be along a line parallel to the imaginary axis of the S Plane, means connected to the outputs of said filters so that the output signals of said filters are combined, said means connected to the outputs of said filters comprising an operational amplifier, at least one of said low pass filters being connected to a first input of said operational amplifier and the remaining ones of said low pass filters being connected to the other input of said operational amplifier so that the outputs of said filters connected to the first input are effectively inverted with respect to the outputs of said filters connected to the second input of said operational amplifier.
Claim 4
Dependent Claim
155 words
A band-pass filter comprising a plurAlity of low pass active filters, each of said filters having related resonating frequency and damping characteristics, said resonating frequency and damping characteristics for each of said filters causing all of the poles of said filters to be along a line parallel to the imaginary axis of the S Plane, means connected to the outputs of said filters so that the output signals of said filters are combined, said means connected to the outputs of said filters comprising an operational amplifier, at least one of said low pass filters being connected to a first input of said operational amplifier and the remaining ones of said low pass filters being connected to the other input of said operational amplifier so that the outputs of said filters connected to the first input are effectively inverted with respect to the outputs of said filters connected to the second input of said operational amplifier.
Claim 5
Dependent Claim
129 words
A band-pass filter comprising a plurality of active filters, each of said filters having related resonating frequency and damping characteristics, said resonating frequency and damping characteristics for each of said filters causing all of the poles of said filters to be along a line parallel to the imaginary axis of the S plane, means connected to the outputs of said filters so that the output signals of said filters are combined, with alternate ones of said filters having their gains inverted with respect to the others of said filters when combined, said filters each having approximately the same gain with the exception of said filters represented by the outside poles on said line parallel to the imaginary axis, said outside poles having gains approximately one-half of the remaining poles.
Claim 6
Dependent Claim
129 words
A band-pass filter comprising a plurality of active filters, each of said filters having related resonating frequency and damping characteristics, said resonating frequency and damping characteristics for each of said filters causing all of the poles of said filters to be along a line parallel to the imaginary axis of the S plane, means connected to the outputs of said filters so that the output signals of said filters are combined, with alternate ones of said filters having their gains inverted with respect to the others of said filters when combined, said filters each having approximately the same gain with the exception of said filters represented by the outside poles on said line parallel to the imaginary axis, said outside poles having gains approximately one-half of the remaining poles.
Claim 7
Dependent Claim
118 words
A band-pass filter comprising a plurality of active filters, each of said filters having related resonating frequency and damping characteristics, said resonating frequency and damping characteristics for each of said filters causing all of the poles of said filters to be along a line parallel to the imaginary axis of the S plane, means connected to the outputs of said filters so that the output signals of said filters are combined, with alternate ones of said filters having their gain inverted with respect to the other of said filters when combined, the poles representative of said filters being equally spaced with the exception of end poles which are spaced approximately one-half the distance of the next adjacent poles.
Claim 8
Dependent Claim
118 words
A band-pass filter comprising a plurality of active filters, each of said filters having related resonating frequency and damping characteristics, said resonating frequency and damping characteristics for each of said filters causing all of the poles of said filters to be along a line parallel to the imaginary axis of the S plane, means connected to the outputs of said filters so that the output signals of said filters are combined, with alternate ones of said filters having their gain inverted with respect to the other of said filters when combined, the poles representative of said filters being equally spaced with the exception of end poles which are spaced approximately one-half the distance of the next adjacent poles.
References Cited (Backward Citations)
US2709206A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-09 | 1976-10-09 | 1977-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-09 | 1980-10-09 | 1981-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-09 | 1984-10-09 | 1985-04-10 | $7700.00 | Window Closed / Lapsed |