US4868524A
Expired / Lapsed
US
⏱️ 0.0 years remaining
RF circuit utilizing a voltage controlled saw oscillator
Assignee: Johns Hopkins University
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Filing: 1988-10-20
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Granted: 1989-09-19
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Expires: 2008-10-20
Abstract
Abstract An RF circuit to generate a stable carrier signal using a Voltage Controlled Saw Oscillator (VCSO) is disclosed. The invention teaches the use of a phase lock loop circuit employing a temperature compensated crystal oscillator (TCXO), or similar stable oscillator, to stabilize the output of the VCSO.
Inventors
- 👤 Raymond J. Costlow
- 👤 Alvin G. Bates
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:17
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/16; H03L7/18; H03L7/183
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
156 words
Circuit comprising: a voltage controlled SAW oscillator (VCSO) having a control voltage input and producing an RF output signal; a reference oscillator for producing an output having a frequency that is essentially temperature stable; a first frequency divider connected to the output of said voltage controlled SAW oscillator (VCSO) for providing an output divided in frequency by a first preselected value; a second frequency divider connected to the output of said reference oscillator for providing an output divided in frequency by a second preselected value; and, a phase comparator means for comparing the frequency and phase of the output from said first frequency divider with the frequency and phase of the output from said second frequency divider and adjusting the control voltage to said voltage controlled SAW oscillator (VCSO) until the divider output signals have the same frequency and phase, thereby maintaining the RF output signal produced by said SAW oscillator (VCSO) at a selected frequency.
Claim 2
Dependent Claim
156 words
Circuit comprising: a voltage controlled SAW oscillator (VCSO) having a control voltage input and producing an RF output signal; a reference oscillator for producing an output having a frequency that is essentially temperature stable; a first frequency divider connected to the output of said voltage controlled SAW oscillator (VCSO) for providing an output divided in frequency by a first preselected value; a second frequency divider connected to the output of said reference oscillator for providing an output divided in frequency by a second preselected value; and, a phase comparator means for comparing the frequency and phase of the output from said first frequency divider with the frequency and phase of the output from said second frequency divider and adjusting the control voltage to said voltage controlled SAW oscillator (VCSO) until the divider output signals have the same frequency and phase, thereby maintaining the RF output signal produced by said SAW oscillator (VCSO) at a selected frequency.
Claim 3
Dependent Claim
49 words
The circuit of claim 1, wherein said phase lock loop means further comprises: a filter means operably coupled between the phase comparator means and the voltage controlled SAW oscillator (VCSO) for controlling the rate at which the control voltage to the voltage controlled SAW oscillator (VCSO) can be changed.
Claim 4
Dependent Claim
39 words
The circuit of claim 1, wherein said phase lock loop means further comprises: a control means for controlling the divide ratio between said first and second frequency dividers, so as to adjust the frequency of the RF output signal.
Claim 5
Dependent Claim
12 words
The circuit of claim 3, wherein said control means is a microprocessor.
Claim 6
Dependent Claim
27 words
The circuit of claim 1, further including a memory means operably coupled to said first and second frequency divider for storing said first and second preselected values.
Claim 7
Dependent Claim
38 words
The circuit of claim 1, wherein said phase lock loop means further comprises a prescaler operably coupled between said voltage controlled SAW oscillator and said first frequency divider for further dividing the output frequency from said RF output.
References Cited (Backward Citations)
US4325032A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-18 | 1993-03-20 | 1993-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-18 | 1997-03-20 | 1997-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-18 | 2001-03-20 | 2001-09-19 | $7700.00 | Window Closed / Lapsed |