US3747028A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Directional tap comprising pi-section high pass filter for use in catv system
Assignee: Lindsay Specialty Products Ltd
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Filing: 1971-04-22
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Granted: 1973-07-17
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Expires: 1991-04-22
Abstract
Abstract Combination directional couplers and splitters for extracting controlled fractions of signal power, for use in CATV or similar signal distribution systems and having improved operating characteristics are obtained by the incorporation of pi-section high-pass filters into such integrated devices. Conventional directional taps are modified by the addition of inductances and capacitances so that the required pi-section high-pass filters are formed, with one inductive element of such a filter being constituted by an inductive deviation, specifically a leakage inductance of an existing component of such a device. Improved radio frequency signal return losses and isolation are provided over a much greater frequency range than was heretofore possible while permitting effective distribution of signal power to a plurality of tap lines.
Inventors
- 👤 F Pennypacker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:31
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/10; H04N7/102; H04N7/104; H03; H03H; H03H7/00; H03H7/48; H03H7/482
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
140 words
A directional tap suitable for use in retrieving a directional radio frequency signal from a transmission line wherein said tap comprises of at least one directional coupler circuit coupled to said transmission line and at least one splitter circuit connected to said directional coupler circuit to provide selective radio frequency signals to a plurality of subscriber stations, said directional coupler circuit including inductive means therein, the improvement comprising in combination: capacitive means connected in a circuit relation with said inductive means in said directional coupler circuit to provide at least one pi-section high-pass filter therein to extend the frequency bandwidth of said directional coupler circuit; and further capacitive means connected in a circuit relation with internal inductive means in said splitter circuit to form at least one pi-section high-pass filter therein to extend the frequency bandwidth of said splitter circuit.
Claim 2
Dependent Claim
140 words
A directional tap suitable for use in retrieving a directional radio frequency signal from a transmission line wherein said tap comprises of at least one directional coupler circuit coupled to said transmission line and at least one splitter circuit connected to said directional coupler circuit to provide selective radio frequency signals to a plurality of subscriber stations, said directional coupler circuit including inductive means therein, the improvement comprising in combination: capacitive means connected in a circuit relation with said inductive means in said directional coupler circuit to provide at least one pi-section high-pass filter therein to extend the frequency bandwidth of said directional coupler circuit; and further capacitive means connected in a circuit relation with internal inductive means in said splitter circuit to form at least one pi-section high-pass filter therein to extend the frequency bandwidth of said splitter circuit.
Claim 3
Dependent Claim
217 words
A directional tap suitable for use in retrieving a directional radio frequency signal from a transmission line wherein said tap comprises of at least one directional coupler circuit coupled to said transmission line and at least one splitter circuit connected to said directional coupler circuit to provide selective radio frequency signals to a plurality of subscriber stations, said directional coupler circuits including inductive means therein, the improvement comprising in combination: capacitive means connected in a circuit relation with said inductive means in said directional coupler circuit to provide at least one pi-section high-pass filter therein to extend the frequency bandwidth of said directional coupler circuit; said inductive means comprises a first power coil and a second power coil connected in series with each other and in parallel with said transmission line and the primary winding of a voltage sensing transformer coupled to said transmission line; and said capacitive means comprises a first capacitor connected in series with said primary winding to form a first inductor-capacitor circuit which is connected in parallel with said first power coil to form a first pi-section high-pass filter; and a second capacitor connected in series with said primary winding to form a second inductor-capacitor circuit which is connected in parallel to said second power coil to form a second pi-section high-pass filter.
Claim 4
Dependent Claim
217 words
A directional tap suitable for use in retrieving a directional radio frequency signal from a transmission line wherein said tap comprises of at least one directional coupler circuit coupled to said transmission line and at least one splitter circuit connected to said directional coupler circuit to provide selective radio frequency signals to a plurality of subscriber stations, said directional coupler circuits including inductive means therein, the improvement comprising in combination: capacitive means connected in a circuit relation with said inductive means in said directional coupler circuit to provide at least one pi-section high-pass filter therein to extend the frequency bandwidth of said directional coupler circuit; said inductive means comprises a first power coil and a second power coil connected in series with each other and in parallel with said transmission line and the primary winding of a voltage sensing transformer coupled to said transmission line; and said capacitive means comprises a first capacitor connected in series with said primary winding to form a first inductor-capacitor circuit which is connected in parallel with said first power coil to form a first pi-section high-pass filter; and a second capacitor connected in series with said primary winding to form a second inductor-capacitor circuit which is connected in parallel to said second power coil to form a second pi-section high-pass filter.
Claim 5
Dependent Claim
82 words
A directional tap according to claim 2 wherein said inductive means further comprises the secondary winding of a current sensing transformer coupled to said transmission line and the primary winding of an autotransformer in said splitter circuit; and said capacitive means further comprises a capacitor connected in series with said primary winding of said autotransformer to form a third inductor-capacitor circuit which is connected in parallel with said secondary winding of said current sensing transformer to form a third pi-section high-pass filter.
Claim 6
Dependent Claim
55 words
A directional tap according to claim 3 wherein said splitter circuit includes internal inductive means comprising the secondary winding of said autotransformer, and a capacitor connected in series with said secondary winding of said autotransformer and the primary winding of an input transformer in a subscriber station to form an output pi-section high-pass filter therein.
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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) | 1976-07-16 | 1977-01-15 | 1977-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-16 | 1981-01-15 | 1981-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-16 | 1985-01-15 | 1985-07-17 | $7700.00 | Window Closed / Lapsed |