US3673509A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Interdigital preamplifier
Assignee: EDWIN J SOSSEN
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Filing: 1970-08-07
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Granted: 1972-06-27
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Expires: 1990-08-07
Abstract
Abstract A bandpass preamplifier for isolating a narrow frequency band, especially in the VHF or UHF range, from interference or out-ofband radiation generated by high energy transmitters operating at frequencies near the desired band. The circuit includes a first turnable combline bandpass filter, employing strip line inductive elements, which provides a narrow band input to a field effect transistor amplifier. A second similar filter receives the amplified signal and furnishes a very narrow band output signal characterized by very strong attenuation of out-of-band interference.
Inventors
- 👤 Robert B Cooper Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:21
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/189; H03F3/19; H03F3/193; H03F3/1935; H01; H01P; H01P1/00; H01P1/20; H01P1/201; H01P1/205
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
144 words
An interdigital preamplifier comprising: radio frequency amplifying means; first filter circuit means coupled to said amplifying means for applying a bandpass input signal thereto, said first circuit means including at least one resonant circuit, said resonant circuit being comprised of a strip line inductive element having a capacitive element coupled thereto; second filter circuit means coupled to said amplifying means for receiving a bandpass output signal therefrom, said second filter circuit means including at least one resonant circuit, said resonant circuit comprised of a strip line inductive element having a capacitive element coupled thereto; and, housing means including top and bottom portions, said strip line inductive elements coupled at both ends thereof to said housing means and arranged in parallel configuration, said top and bottom portions of said housing means forming upper and lower ground planes with respect to said strip line inductive elements.
Claim 2
Dependent Claim
144 words
An interdigital preamplifier comprising: radio frequency amplifying means; first filter circuit means coupled to said amplifying means for applying a bandpass input signal thereto, said first circuit means including at least one resonant circuit, said resonant circuit being comprised of a strip line inductive element having a capacitive element coupled thereto; second filter circuit means coupled to said amplifying means for receiving a bandpass output signal therefrom, said second filter circuit means including at least one resonant circuit, said resonant circuit comprised of a strip line inductive element having a capacitive element coupled thereto; and, housing means including top and bottom portions, said strip line inductive elements coupled at both ends thereof to said housing means and arranged in parallel configuration, said top and bottom portions of said housing means forming upper and lower ground planes with respect to said strip line inductive elements.
Claim 3
Dependent Claim
23 words
An interdigital preamplifier as in claim 1, wherein: said first and second filter circuit means each include a plurality of said resonant circuits.
Claim 4
Dependent Claim
36 words
An interdigital preamplifier as in claim 2, wherein: said capacitive elements included in said plurality of resonant circuits are adjustable, whereby said first and second filter circuit means are tunable to a selected frequency pass band.
Claim 5
Dependent Claim
50 words
An interdigital preamplifier as in claim 2, wherein: said first and second filter circuit means each include at least one resonant circuit having a strip line inductive element of a first structural configuration, and at least one resonant circuit having a strip line inductive element of a second structural configuration.
Claim 6
Dependent Claim
50 words
An interdigital preamplifier as in claim 2, wherein: said first and second filter circuit means each include at least one resonant circuit having a strip line inductive element of tubular configuration, and at least one resonant circuit having a strip line inductive element comprised of a pair of metalized strips.
Claim 7
Dependent Claim
20 words
An interdigital preamplifier as in claim 1, wherein: said strip line inductive elements are imprinted on etched printed circuit boards.
Claim 8
Dependent Claim
18 words
An interdigital preamplifier as in claim 2, wherein: said radio frequency amplifying means includes a field effect transistor.
Claim 9
Dependent Claim
18 words
An interdigital preamplifier as in claim 7, wherein: said field effect transistor is arranged in common gate configuration.
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) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |