US3614637A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Divergent filter system
Assignee: United States Department of the Army
•
Filing: 1969-10-31
•
Granted: 1971-10-19
•
Expires: 1989-10-31
Abstract
Abstract An electrical, easily microminiaturized filter system which exhibits a very steep rolloff, substantially rectangular response by obtaining the divergence or algebraic summation between the positively half-wave rectified response of a band-pass filter and the negatively half-wave rectified response of a band reject filter, both band filters having the same center frequency and bandwidth. Also provided is a synthesizer, including an emitter coupled monostable multivibrator, which is input bias controlled and output modulated to further enhance filter system response rectangularity through the controlled production of low amplitude narrow pulses in the region of rolloff and high amplitude broad pulses at the center of the band.
Inventors
- 👤 Jacob H Kubanoff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 00:35
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/04; H03H11/12; H03H11/1217
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
99 words
A steep rolloff divergent filter system, comprising: first band-pass filter means and a second band reject filter means both having identical center frequencies and bandwidth, for respectively providing first and second output signals upon the receipt of a signal within said bandwidth; rectifying means connected to said first and said second filter means for respectively providing only the positive excursions of said first output signal and only the negative excursions of said second output signal; and circuit means connected to said rectifying means for providing a DC summed output signal upon the receipt of said positive and negative excursions.
Claim 2
Dependent Claim
99 words
A steep rolloff divergent filter system, comprising: first band-pass filter means and a second band reject filter means both having identical center frequencies and bandwidth, for respectively providing first and second output signals upon the receipt of a signal within said bandwidth; rectifying means connected to said first and said second filter means for respectively providing only the positive excursions of said first output signal and only the negative excursions of said second output signal; and circuit means connected to said rectifying means for providing a DC summed output signal upon the receipt of said positive and negative excursions.
Claim 3
Dependent Claim
31 words
A steep rolloff filter system according to claim 1, further including: synthesizer means connected to said circuit means for converting said DC output signal into a signal of predetermined wave shape.
Claim 4
Dependent Claim
51 words
A steep rolloff filter system according to claim 2, wherein said first filter means comprises: a first operational amplifier having an inverting and a noninverting input; and a band reject filter connected to said inverting input and said first amplifier being connected in the negative feedback mode with said reject filter.
Claim 5
Dependent Claim
36 words
A steep rolloff filter system according to claim 3, wherein said second filter means comprises: a second operational amplifier of controllable gain having a noninverting input thereof connected to the inverting input of said first amplifier.
Claim 6
Dependent Claim
46 words
A steep rolloff filter system according to claim 4, wherein said circuit means comprises: a summing circuit for receiving said positive and negative excursions; and a long time constant integrator connected to receive the summed output from said summing circuit for providing said DC output signal.
Claim 7
Dependent Claim
78 words
A steep rolloff filter system according to claim 5, wherein said synthesizer means connected to said circuit means comprises: a monostable multivibrator connected to receive as a bias current said DC output signal; an amplifier connected to receive said DC output signal for amplifying said signal for supply to said multivibrator to modulate the output signal therefrom; and further including means connected to the output of said first filter means for providing a trigger signal to said multivibrator.
Claim 8
Dependent Claim
43 words
A steep rolloff filter system accordingly to claim 6, wherein said means connected to said circuit means further includes: a filter connected to the output of said multivibrator for providing a reconstituted sinusoid upon the receipt of the output signal from said multivibrator.
Claim 9
Dependent Claim
48 words
A steep rolloff filter system according to claim 6, wherein said means connected to said circuit means further includes: a long time constant integrator connected to the output of said multivibrator for providing an integrated DC output signal upon the receipt of the output signal from said multivibrator.
Claim 10
Dependent Claim
56 words
A steep rolloff filter system according to claim 2, wherein said first and second filter means comprise: a passive band pass filter; a first amplifier connected to said band pass filter; a passive band reject filter; and a second amplifier, said second amplifier having a variable gain and connected to the output of said reject filter.
Claim 11
Dependent Claim
89 words
A steep rolloff filter system according to claim 9, wherein said circuit means comprises: a first long time constant integrator connected to said first amplifier for integrating the signal amplified thereby; a second long time constant integrator connected to said second amplifier for integrating the signal amplified thereby; a unity gain inverter connected to said second integrator for inverting the output signal therefrom; and a summing circuit connected both to said first integrator and said invertor for summing the output signals produced Thereby to provide said DC output signal.
Claim 12
Dependent Claim
77 words
A steep rolloff filter system according to claim 10, wherein said means connected to said circuit means comprises: a monostable multivibrator connected to receive as a bias current said DC output signal; an amplifier connected to receive said DC output signal for amplifying said signal for supply to said multivibrator to modulate the output signal therefrom; and further including means connected to the output of said first filter means for providing a trigger signal to said multivibrator.
Claim 13
Independent Claim
62 words
A method for obtaining a steep rolloff filter response, comprising the steps of: simultaneously band-pass and band reject filtering a received signal over the same bandwidths and center frequencies to yield filter responses; positively rectifying a selected one of said filter responses; negatively rectifying the other of said filter responses; and summing the two rectified responses to provide said steep rolloff response.
Claim 14
Independent Claim
62 words
A method for obtaining a steep rolloff filter response, comprising the steps of: simultaneously band-pass and band reject filtering a received signal over the same bandwidths and center frequencies to yield filter responses; positively rectifying a selected one of said filter responses; negatively rectifying the other of said filter responses; and summing the two rectified responses to provide said steep rolloff response.
Claim 15
Dependent Claim
21 words
The method according to claim 12 further including the step of: amplifying the band reject filter response prior to rectification thereof.
References Cited (Backward Citations)
US3021481A
Cited
US3109143A
Cited
US3223929A
Cited
US3383600A
Cited
US3371225A
Cited
US3308389A
Cited
US3386039A
Cited
US3349257A
Cited
US3508075A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-18 | 1975-04-19 | 1975-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-18 | 1979-04-19 | 1979-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-18 | 1983-04-19 | 1983-10-19 | $7700.00 | Window Closed / Lapsed |