Patent US4536722A successfully refreshed from Google Patents.
US4536722A
Expired / Lapsed
US
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Apparatus for rapidly switching a controlled signal source and method therefor
Assignee: Gresham Worldwide Inc
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Filing: 1982-06-23
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Granted: 1985-08-20
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Expires: 2002-06-23
Abstract
Abstract In a controlled signal generator or specifically a microwave frequency signal generator, which requires a quieting capacitor, improved switching speed without degrading noise performance is provided by switching out the quieting capacitor during frequency changes, precharging it to the new condition, and then reconnecting it for normal operation. Other error causing current drains are also compensated for.
Inventors
- 👤 Lawrence A. Kaye
- 👤 Robert Mayer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:26
CPC Classifications
H; H03; H03L; H03L7/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
141 words
In a microwave frequency signal generator having an oscillator which requires capacitive filtering means to reduce noise, said oscillator being driven and tuned by a constant current source so that the output frequency of said oscillator is proportional to the current from said constant current source: a pair of current inputs for said oscillator connected to said constant current source; means included in said current source for changing the magnitude of said current and therefore the output frequency of said oscillator; switching means for selectively connecting said filtering means across said input pair and disconnecting said filtering means during a said frequency change; and comparator means for sensing the voltage across said oscillator input pair, comparing the oscillator input voltage with the voltage across said filtering means, and charging or discharging said filtering means to substantially match said oscillator input voltage.
Claim 2
Dependent Claim
141 words
In a microwave frequency signal generator having an oscillator which requires capacitive filtering means to reduce noise, said oscillator being driven and tuned by a constant current source so that the output frequency of said oscillator is proportional to the current from said constant current source: a pair of current inputs for said oscillator connected to said constant current source; means included in said current source for changing the magnitude of said current and therefore the output frequency of said oscillator; switching means for selectively connecting said filtering means across said input pair and disconnecting said filtering means during a said frequency change; and comparator means for sensing the voltage across said oscillator input pair, comparing the oscillator input voltage with the voltage across said filtering means, and charging or discharging said filtering means to substantially match said oscillator input voltage.
Claim 3
Dependent Claim
87 words
A generator as in claim 1 where said constant current source is responsive to a predetermined input voltage for changing its output current and includes a feedback loop for comparing its output with said input voltage and where said switching means draws a control current which forms part of the current driving said oscillator, and including sensing means, which form a part of said feedback loop, for summing said control current in a common node of said constant current source whereby the linearity of tuning is maintained.
Claim 4
Dependent Claim
18 words
A generator as in claim 2 where said switching means includes a Darlington circuit for limiting current drains.
Claim 5
Dependent Claim
20 words
A generator as in claim 1 including second switching means for disconnecting said comparator means except during said frequency changes.
Claim 6
Dependent Claim
27 words
A generator as in claim 1 where said oscillator input pair is connected to a copper coil sensitive to temperature and therefore requiring said constant current source.
Claim 7
Dependent Claim
20 words
A generator as in claim 1 where said comparator means utilizes a current source independent of said constant current source.
Claim 8
Dependent Claim
29 words
A generator as in claim 1 where said capacitive filtering means and said oscillator input pair are in parallel and only one side of said filtering means is switched.
References Cited (Backward Citations)
US4007429A
Cited
US4219783A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-08-19 | 1989-02-18 | 1989-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-19 | 1993-02-18 | 1993-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-19 | 1997-02-18 | 1997-08-20 | $7700.00 | Window Closed / Lapsed |