US3775704A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hybrid filter
Assignee: General Electric Co
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Filing: 1973-01-02
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Granted: 1973-11-27
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Expires: 1993-01-02
Abstract
Abstract A hybrid filter having the characteristics of a hybrid coupler and high and low pass filters combined. The hybrid filter provides high pass and low pass frequency ports and employs a complementary filtering and phase inversion means such as a center-tapped inductor to isolate and confine the high and low frequencies to their respective ports. The hybrid filter provides a constant input impedance at all frequencies by employing reactive elements of critical values.
Inventors
- 👤 N Gittinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:49
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/46
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
186 words
A hybrid filter comprising: a. a first common port; b. a second common port; c. a low pass port d. a high pass port; e. first and second low pass filter means, said first low pass filter means electrically connecting said first common port and said low pass port, said second low pass filter electrically connecting said second common port and said high pass port, and said first and second low pass filter means having substantially identical band pass frequency responses; f. high pass filter means electrically connecting said first common port and said high pass port, and said high pass filter means having a band pass frequency response higher than frequency response of said first or second low pass filter means; and g. complementary filtering and phase inversion means electrically connecting said second common port and said low pass port, and said complementary filtering and phase inversion means having a band pass frequency response substantially identical to the band pass frequency response of said high pass filter means and further having a capability for phase inverting undesired frequencies to effect cancellation of the undesired frequencies.
Claim 2
Dependent Claim
186 words
A hybrid filter comprising: a. a first common port; b. a second common port; c. a low pass port d. a high pass port; e. first and second low pass filter means, said first low pass filter means electrically connecting said first common port and said low pass port, said second low pass filter electrically connecting said second common port and said high pass port, and said first and second low pass filter means having substantially identical band pass frequency responses; f. high pass filter means electrically connecting said first common port and said high pass port, and said high pass filter means having a band pass frequency response higher than frequency response of said first or second low pass filter means; and g. complementary filtering and phase inversion means electrically connecting said second common port and said low pass port, and said complementary filtering and phase inversion means having a band pass frequency response substantially identical to the band pass frequency response of said high pass filter means and further having a capability for phase inverting undesired frequencies to effect cancellation of the undesired frequencies.
Claim 3
Dependent Claim
36 words
The hybrid filter as recited in claim 1, wherein: a. said first and second low pass filter means comprise low pass T filters; and b. said high pass filter means comprises a high pass T filter.
Claim 4
Dependent Claim
40 words
The hybrid filter as recited in claim 2 wherein said complementary filtering and phase inversion means comprises: a. first and second capacitors; and b. an inductor having a center tap and being electrically connected between said first and second capacitors.
Claim 5
Dependent Claim
128 words
The hybrid filter as recited in claim 3 wherein: a. said low pass T filters have inductors of value L and capacitors of value C/K; b. said high pass T filter has capacitors of value C and an inductor of value KL; c. the first and second capacitors have a value of C and the inductor having a center tap has an effective value of KL in the complementary filtering and phase inversion means, where K 0.34444, L 2.4516316R2C, and fc (2 pi (LC)1/2) 1, where R is a value of the impedance characteristic of a transmission line to which the hybrid filter is adapted to be connected and fc is a crossover frequency separating the band pass frequency responses of said low and high pass filter means.
References Cited (Backward Citations)
US2115138A
Cited
US3593209A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |