US3601723A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic tuning apparatus for microwave circuits
Assignee: NAT RES DEV
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Filing: 1969-10-07
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Granted: 1971-08-24
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Expires: 1989-10-07
Abstract
Abstract Tuning apparatus for a resonant cavity comprises a varactor diode capacitively coupled into the cavity by means of a halfwavelength of, or n half-wavelengths of, a transmission line, and a return path for the varactor current is provided by an inductive member connected a quarter-wavelength from one end of the line. Bias current supply leads, with a bypass capacitor connected across them, are connected either in series with the varactor diode or in series with the inductive member. The inductive member may be a spiral wire.
Inventors
- 👤 Albert Henry Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:45
CPC Classifications
H; H03; H03J; H03J3/00; H03J3/02; H03J3/16; H03J3/18; H03J3/185
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
181 words
Apparatus for electronic tuning an electromagnetically resonant structure, a varactor capacitance, a transmission line, connected at one end to said electromagnetically resonant structure so that it will be capacitively coupled to the electric field of an electromagnetic wave resonant therein, and connected at its other end to said varactor capacitance, said line comprising an inner conductor and an outer conductor and having electrical length substantially equal to n times lambda /2 where n is an integer and lambda /2 is a half-wavelength at the resonant frequency of said electromagnetically resonant structure, an inductive member connected to said inner conductor at a position between the said varactor capacitance and the said resonant structure, said position being substantially at an electrical length m lambda /4 from one end of said transmission line where m is an odd integer, bias current supply means, for passing a bias current through said outer conductor, said inductive member and through said varactor capacitance to adjust its capacitance, and a bypass capacitor connected in parallel with said bias current supply means to decouple it from said electromagnetic waves.
Claim 2
Dependent Claim
181 words
Apparatus for electronic tuning an electromagnetically resonant structure, a varactor capacitance, a transmission line, connected at one end to said electromagnetically resonant structure so that it will be capacitively coupled to the electric field of an electromagnetic wave resonant therein, and connected at its other end to said varactor capacitance, said line comprising an inner conductor and an outer conductor and having electrical length substantially equal to n times lambda /2 where n is an integer and lambda /2 is a half-wavelength at the resonant frequency of said electromagnetically resonant structure, an inductive member connected to said inner conductor at a position between the said varactor capacitance and the said resonant structure, said position being substantially at an electrical length m lambda /4 from one end of said transmission line where m is an odd integer, bias current supply means, for passing a bias current through said outer conductor, said inductive member and through said varactor capacitance to adjust its capacitance, and a bypass capacitor connected in parallel with said bias current supply means to decouple it from said electromagnetic waves.
Claim 3
Dependent Claim
27 words
Apparatus as claimed in claim 1 and wherein the said electrical length of said transmission line is substantially one half-wavelength, lambda /2, at the said resonant frequency.
Claim 4
Dependent Claim
53 words
Apparatus as claimed in claim 1 and wherein said varactor capacitance and said bypass capacitor are electrically connected in series between the said inner conductor and the said outer conductor of the said transmission line at the said other end thereof, and the said inductive member is connected to the said outer conductor.
Claim 5
Dependent Claim
34 words
Apparatus as claimed in claim 3 and wherein said inductive member is a spiral conductive lead, connected at its inner end to said inner conductor and at its outer end to said outer conductor.
Claim 6
Dependent Claim
46 words
Apparatus as claimed in claim 1, wherein said varactor capacitance has one electrode connected to said inner conductor and one electrode connected to said outer conductor, and said bypass capacitance has one connection connected to said outer conductor and one connection connected to said inductive member.
Claim 7
Dependent Claim
37 words
Apparatus as claimed in claim 5 and wherein said inductive member is a spiral conductive lead, connected at its inner end to said inner conductor and at its outer end to said connection of said bypass capacitance.
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) | 1974-08-23 | 1975-02-22 | 1975-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-23 | 1979-02-22 | 1979-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-23 | 1983-02-22 | 1983-08-24 | $7700.00 | Window Closed / Lapsed |