US3593209A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hybrid filter for two-way transmission over a single line
Assignee: General Electric Co
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Filing: 1969-12-29
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Granted: 1971-07-13
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Expires: 1989-12-29
Abstract
Abstract A hybrid filter is disclosed wherein the characteristics of a hybrid coupler and high and low pass filters are combined. Each port of the hybrid filter exhibits a constant input impedance that is independent of frequency. The hybrid filter provides a common, low pass and a high pass port, thus providing both frequency and power isolation between branches.
Inventors
- 👤 Norman C Gittinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:16
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/36; H04B3/38; H03; H03H; H03H7/00; H03H7/46
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
138 words
A hybrid filter comprising: a common first port, a low pass second port, a high pass third port, said first, second and third ports each having a signal terminal and a common terminal, first filter means having a low frequency band pass response and connecting said first port to said second port, second filter means having a band-pass response of substantially higher frequency than that of said first filter means and connecting said first port to said third port, and complementary filtering and phase inverting means connecting said second port to said third port and forming a bridge circuit including said first, second, and third ports, said first and second filter means and said complementary filtering and inverting means providing high signal attenuation between said second and third ports and thereby providing both frequency and power isolation therebetween.
Claim 2
Dependent Claim
138 words
A hybrid filter comprising: a common first port, a low pass second port, a high pass third port, said first, second and third ports each having a signal terminal and a common terminal, first filter means having a low frequency band pass response and connecting said first port to said second port, second filter means having a band-pass response of substantially higher frequency than that of said first filter means and connecting said first port to said third port, and complementary filtering and phase inverting means connecting said second port to said third port and forming a bridge circuit including said first, second, and third ports, said first and second filter means and said complementary filtering and inverting means providing high signal attenuation between said second and third ports and thereby providing both frequency and power isolation therebetween.
Claim 3
Dependent Claim
29 words
A hybrid filter as set forth in claim 1 wherein said first first filter means comprises inductive reactive means; and said second filter means comprises capacitive reactive filter means.
Claim 4
Dependent Claim
25 words
A hybrid filter as set forth in claim 1 Wherein said first and second filter means comprise low pass and high pass T filters, respectively.
Claim 5
Dependent Claim
59 words
A hybrid filter as set forth in claim 1 wherein said complementary filtering and phase inverting means comprises: third filter means having characteristics like said second filter means and coupling said phase inverting means to said second port; and fourth filter means having characteristics like said first filter means and coupling said phase inverting means to said third port.
Claim 6
Dependent Claim
95 words
A hybrid filter as set forth in claim 4 wherein: said first and fourth filter means comprise series inductive reactive means, said second and third filter means comprise series capacitive reactive means, the value of the inductive reactive means L and capacitive reactive means C being related as L 2R2C where R is the characteristic impedance of the hybrid filter and of a transmission line to which it is adapted to be connected, and said phase inverting means comprises a center-tapped transformer having its center-tap for connection as a fourth port of said hybrid filter.
Claim 7
Dependent Claim
94 words
A hybrid filter as set forth in claim 5 wherein: said center-tapped transformer has two signal leads in addition to said center-tap, on of said signal leads being connected to said third filter means and the other of said signal leads being connected to said fourth filter means, and further comprising: resistance means of predetermined value connected across said center-tapped transformer by means of said two signal leads, the value of said resistance means equal to 4R, each port of the hybrid filter presenting a constant input impedance that is independent of operating frequency.
Claim 8
Dependent Claim
32 words
A hybrid filter as set forth in claim 5 wherein: said inverting means further comprises a secondary winding on said center-tapped transformer for connection as a fourth port of said hybrid filter.
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) | 1974-07-12 | 1975-01-11 | 1975-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-12 | 1979-01-11 | 1979-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-12 | 1983-01-11 | 1983-07-13 | $7700.00 | Window Closed / Lapsed |