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US4378532A
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Oscillator mode suppression apparatus having bandpass effect
Assignee: Agilent Technologies Inc
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Filing: 1981-08-27
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Granted: 1983-03-29
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Expires: 2001-08-27
Abstract
Abstract An apparatus utilizing the basic oscillation characteristics of the Colpitts or Pierce and Hartley oscillator configurations. In this embodiment the basic shunt reactive shunt arms are replaced with a selected pair of tank circuits or one of the shunt arms with a series-parallel tank circuit. These tank circuits are tuned such that the sign of their effective reactances are the same between the range of resonant frequencies of the individual tank circuits or of the series and parallel resonant frequencies of the series-parallel tank. When this occurs and their sign differs from the sign of the effective reactance of the series reactive element, there is a 180° signal phase shift in the feedback loop, and therefore oscillation.
Inventors
- 👤 John R. Burgoon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:15
CPC Classifications
H; H03; H03B; H03B5/00; H03B5/30; H03B5/32; H03B2200/00; H03B2200/0002; H03B2200/0012
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
209 words
Signal Oscillator with mode suppression apparatus for limiting the frequencies of oscillation to a selected band of frequencies, said apparatus comprising: inverting amplifier means having an input terminal and an output terminal; and signal feedback means for providing a 180° phase shift in the selected band of frequencies, said signal feedback means including: crystal resonator means connected in series between the input and output terminals of the inverting amplifier means for producing a relatively stable oscillator output signal; and first and second shunt reactive means for suppressing oscillation outside the selected band of frequencies, said first shunt reactive means having one end connected to the input terminal of the inverting amplifier means, said second shunt reactive means having one end connected to the output terminal of the inverting amplifier means, the other ends of the first and second shunt reactive means being connected one to the other; at least one of said first and second shunt reactive means having a resonant tank circuit, said resonant tank circuit having a reactance value such that for each frequency outside the selected band of frequencies at least one of said first and second shunt reactive means has reactance value of the same sign as the reactance value of the crystal resonator means.
Claim 2
Dependent Claim
209 words
Signal Oscillator with mode suppression apparatus for limiting the frequencies of oscillation to a selected band of frequencies, said apparatus comprising: inverting amplifier means having an input terminal and an output terminal; and signal feedback means for providing a 180° phase shift in the selected band of frequencies, said signal feedback means including: crystal resonator means connected in series between the input and output terminals of the inverting amplifier means for producing a relatively stable oscillator output signal; and first and second shunt reactive means for suppressing oscillation outside the selected band of frequencies, said first shunt reactive means having one end connected to the input terminal of the inverting amplifier means, said second shunt reactive means having one end connected to the output terminal of the inverting amplifier means, the other ends of the first and second shunt reactive means being connected one to the other; at least one of said first and second shunt reactive means having a resonant tank circuit, said resonant tank circuit having a reactance value such that for each frequency outside the selected band of frequencies at least one of said first and second shunt reactive means has reactance value of the same sign as the reactance value of the crystal resonator means.
Claim 3
Dependent Claim
41 words
Signal oscillator with mode suppression apparatus as in claim 1 wherein one of said first and second shunt reactive means includes a parallel resonant tank and the other of said first and second shunt reactive means includes a series resonant tank.
Claim 4
Dependent Claim
86 words
Signal oscillator with mode suppression apparatus as in claim 2 wherein: said parallel resonant tank has a resonant frequency, f 1 , and said parallel tank has a negative reactance above f 1 and a positive reactance below f 1 ; and said series resonant tank has a resonant frequency, f 2 , and said series tank has a positive reactance above f 2 and a negative reactance below f 2 ; said resonant frequencies f 1 and f 2 defining said selected band of frequencies.
Claim 5
Dependent Claim
55 words
Signal oscillator with mode suppression apparatus as in claim 3 wherein f 1 is selected to be less than f 2 causing said crystal resonator means to assume a positive reactance value between f 1 and f 2 and the oscillator to operate in a Colpitts configuration between frequencies f 1 and f 2 .
Claim 6
Dependent Claim
55 words
Signal oscillator with mode suppression apparatus as in claim 3 wherein f 2 is selected to be less than f 1 causing said crystal resonator means to assume a negative reactance value between f 2 and f 1 and the oscillator to operate in the Hartley configuration between frequencies f 2 and f 1 .
Claim 7
Dependent Claim
80 words
Signal oscillator with mode suppression apparatus as in claim 1 wherein: one of said first and second shunt reactive means includes a tank circuit having a series resonant path and a parallel resonant path; and the other of said first and second shunt reactive means includes a first non-resonant reactive circuit; a tank circuit configured as above defined has a series resonant frequency and a parallel resonant frequency, these frequencies defining the band of frequencies between which oscillation is possible.
Claim 8
Dependent Claim
30 words
Signal oscillator with mode suppression apparatus as in claim 6 wherein the tank circuit comprises a series resonant reactive circuit path in parallel with a second non-resonant reactive circuit path.
Claim 9
Dependent Claim
26 words
Signal oscillator with mode suppression apparatus as in claim 7 wherein the series resonant reactive circuit path comprises an inductor connected in series with a capacitor.
Claim 10
Dependent Claim
29 words
Signal oscillator with mode suppression apparatus as in claim 8 wherein: said second non-resonant reactive circuit path comprises an inductor; and said first non-resonant reactive circuit comprises a capacitor.
Claim 11
Dependent Claim
29 words
Signal oscillator with mode suppression apparatus as in claim 9 wherein: said second non-resonant reactive circuit path comprises a capacitor; and said first non-resonant reactive circuit comprises an inductor.
Claim 12
Dependent Claim
30 words
Signal oscillator with mode suppression apparatus as in claim 6 wherein the tank circuit comprises a parallel resonant reactive circuit path in series with a second non-resonant reactive circuit path.
Claim 13
Dependent Claim
26 words
Signal oscillator with mode suppression apparatus as in claim 11 wherein the parallel resonant reactive circuit path comprises an inductor connected in parallel with a capacitor.
Claim 14
Dependent Claim
29 words
Signal oscillator with mode suppression apparatus as in claim 12 wherein: said second non-resonant reactive circuit path comprises an inductor; and said first non-resonant reactive circuit comprises a capacitor.
Claim 15
Dependent Claim
29 words
Signal oscillator with mode suppression apparatus as in claim 13 wherein: said second non-resonant reactive circuit path comprises a capacitor; and said first non-resonant reactive circuit comprises an inductor.
References Cited (Backward Citations)
US2608648A
Cited
US3560879A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-03-28 | 1986-09-27 | 1987-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-03-28 | 1990-09-27 | 1991-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-03-28 | 1994-09-27 | 1995-03-29 | $7700.00 | Window Closed / Lapsed |