US3806831A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ultra-stable oscillator with complementary transistors
Assignee: National Aeronautics and Space Administration
•
Filing: 1972-12-14
•
Granted: 1974-04-23
•
Expires: 1992-12-14
Abstract
Abstract A high frequency oscillator, having both good short and long term stability, is formed by including a piezoelectric crystal in the base circuit of a first bi-polar transistor circuit, the bipolar transistor itself operated below its transitional frequency and having its emitter load chosen so that the input impedance, looking into the base thereof, exhibits a negative resistance in parallel with a capacitive reactance. Combined with this basic circuit is an auxiliary, complementary, second bi-polar transistor circuit of the same form as the first bi-polar transistor circuit, with the piezoelectric crystal being common to both circuits. By this configuration, variations in the input impedance of the first bi-polar transistor, resulting from changes in the transitional frequency due to small changes in quiescent current, are substantially cancelled by opposite variations in the second bi-polar transistor circuit, thereby achieving from the oscillator a signal having its frequency of oscillation stable over long time periods as well as short time periods.
Inventors
- 👤 L Kleinberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:56
CPC Classifications
H; H03; H03B; H03B7/00; H03B7/02; H03B7/06
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
132 words
A stable high frequency oscillator having its frequency of oscillation stable over long time periods as well as short time periods comprising: a pair of complementary active stages including a first electron discharge device forming one of said pair of complementary active stages and a second electron discharge device forming the other of said pair of complementary active stages; means for creating a negative resistance and capacitive reactance in said pair of complementary stages including a pair of parallel circuits of bias resistor and capacitor, one of said pair of parallel circuits being connected with said first electron discharge device and the other of said pair of parallel circuits being connected with said second electron discharge device; and an inductive impedance element connected in common with said pair of complementary active stages.
Claim 2
Dependent Claim
132 words
A stable high frequency oscillator having its frequency of oscillation stable over long time periods as well as short time periods comprising: a pair of complementary active stages including a first electron discharge device forming one of said pair of complementary active stages and a second electron discharge device forming the other of said pair of complementary active stages; means for creating a negative resistance and capacitive reactance in said pair of complementary stages including a pair of parallel circuits of bias resistor and capacitor, one of said pair of parallel circuits being connected with said first electron discharge device and the other of said pair of parallel circuits being connected with said second electron discharge device; and an inductive impedance element connected in common with said pair of complementary active stages.
Claim 3
Dependent Claim
17 words
The stable high frequency oscillator of claim 1 wherein said inductive impedance element is a piezoelectric crystal.
Claim 4
Dependent Claim
53 words
The stable high frequency oscillator of claim wherein said first electron discharge device is a bi-polar pnp transistor having a first transitional frequency; and said second electron discharge device is a bi-polar npn transistor having a second transitional frequency, where said first transitional frequency and said value of transitional frequency are substantially equal.
Claim 5
Dependent Claim
17 words
The stable high frequency oscillator of claim 3, further including an impedance means shunting said piezoelectric crystal.
Claim 6
Dependent Claim
187 words
The stable high frequency oscillator of claim 4, wherein said pair of stages further includes a source of dc potential having a positive terminal and a negative terminal; said pnp transistor has a collector, an emitter, and a base electrode; and said npn transistor has a collector, an emitter, and a base electrode; said base electrode of said pnp transistor connected in common with said base electrode of said npn transistor, a first one of said pair of parallel circuits of bias resistor and capacitor connector between said positive terminal of said source of dc potential and said emitter electrode of said pnp transistor, a second one of said pair of parallel circuits of bias resistor and capacitor connected between said collector electrode of said pnp transistor and said emitter electrode of said pnp transistor, said collector electrode of said npn transistor connected to said positive terminal of said source of dc potential, and said piezoelectric crystal connected between said base electrode and collector electrode of said pnp transistor, with said collector electrode thereof also being connected to said negative terminal of said source of dc potential.
Claim 7
Dependent Claim
32 words
The stable high frequency oscillator of claim 5, wherein said impedance means includes a parallel combination of a fine tuning capacitor with a variable resistor in series with a dc blocking capacitor.
Claim 8
Dependent Claim
29 words
The stable high frequency oscillator of claim 6, wherein the capacitance values of the capacitors of said pair of parallel circuits of bias resistor and capacitor are substantially equal.
Claim 9
Dependent Claim
54 words
The stable high frequency oscillator of claim 7, wherein the values of the bias resistors of said pair of parallel circuits of bias resistor and capacitor are chosen such the bias voltage at said base electrode of said npn transistor is substantially equal to one half the voltage of said source of dc potential.
Claim 10
Dependent Claim
38 words
The stable high frequency oscillator of claim 8 wherein said values of said bias resistors are substantially equal and each is at least ten times greater than the capacitive reactance of the capacitor with which it is shunting.
Claim 11
Dependent Claim
34 words
The stable high frequency oscillator of claim 5, further including a resistor, wherefrom the output of said oscillator is derived, connecting said collector electrode of said npn transistor to said source of dc potential.
References Cited (Backward Citations)
US3475698A
Cited
US3676801A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-22 | 1977-10-22 | 1978-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-22 | 1981-10-22 | 1982-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-22 | 1985-10-22 | 1986-04-23 | $7700.00 | Window Closed / Lapsed |