Patent US4215325A successfully refreshed from Google Patents.
US4215325A
Expired / Lapsed
US
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Minimal distortion video bandpass filter
Assignee: United States Department of the Navy
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Filing: 1979-03-09
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Granted: 1980-07-29
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Expires: 1999-03-09
Abstract
Abstract The present video bandpass filter passes a sinusoidal video output in response to a square pulse input. The video band-pass filter rejects d.c. and low frequency signal components as well as noise and spurious signals generated at the transmitting source. The video bandpass filter is comprised of an M-derived filter, a series-tuned notch filter, and a final d.c. blocking series-tuned filter which, together, pass the desired video with minimal distortion.
Inventors
- 👤 Francis N. Sansone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:19
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/01; H03H7/0115; H03H7/06; H03H7/17; H03H7/1741; H03H7/175; H03H7/1758
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
102 words
A bandpass filter having a mark-and-space format RF rectangular pulse input and producing a sinusoidal output in response to the rectangular pulse input, comprising, in combination: a first state comprising a resistance connected to the ground at one end and to the pulse input at the other, a second stage, in parallel with the first stage, comprising an M-derived filter, a third stage, connected to the second stage, comprising a notch filter, and a fourth stage, connected to the third stage, comprising means for blocking out d.c. signal components and peaking the output response at a desired frequency in the prescribed bandwidth.
Claim 2
Dependent Claim
102 words
A bandpass filter having a mark-and-space format RF rectangular pulse input and producing a sinusoidal output in response to the rectangular pulse input, comprising, in combination: a first state comprising a resistance connected to the ground at one end and to the pulse input at the other, a second stage, in parallel with the first stage, comprising an M-derived filter, a third stage, connected to the second stage, comprising a notch filter, and a fourth stage, connected to the third stage, comprising means for blocking out d.c. signal components and peaking the output response at a desired frequency in the prescribed bandwidth.
Claim 3
Dependent Claim
38 words
A bandpass filter, as in claim 1, wherein the third stage comprises: a parallel RL network connected at one end to the output of the second stage and coupled to ground through a capacitor at the other end.
Claim 4
Dependent Claim
45 words
A bandpass, filter, as in claim 2, wherein the fourth stage comprises a serial LC circuit the input to which is connected to the output of the second stage and the output from said fourth stage being a sinusoidal waveform corresponding to the pulse input.
Claim 5
Dependent Claim
59 words
A bandpass filter, as in claim 3, wherein the second stage comprises: inductors in series, and an LC circuit connected at one end between the inductors in series and connected at the other end to the ground, pulse input to the bandpass filter entering both the resistance in the first stage and the first inductor in the second stage.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-07-29 | 1984-01-28 | 1984-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-07-29 | 1988-01-28 | 1988-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-07-29 | 1992-01-28 | 1992-07-29 | $7700.00 | Window Closed / Lapsed |