US3573631A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oscillator circuit with series resonant coupling to mixer
Assignee: RCA Licensing Corp
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Filing: 1968-08-30
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Granted: 1971-04-06
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Expires: 1988-08-30
Abstract
Abstract An oscillator circuit tuned by a voltage dependent variable capacitance diode is coupled to a mixer stage by a wide band injection circuit which includes a series connected inductor and capacitor adapted to series resonate at a frequency within the oscillator tuning range. A resistor interconnects the voltage dependent variable capacitance diode and a tuning bias potential supply. The resistor is of a value to cause the tuning of the oscillator circuit to track the tuning of the other circuits controlled by the bias supply.
Inventors
- 👤 David J Carlson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:27
CPC Classifications
H; H03; H03B; H03B5/00; H03B5/08; H03B5/12; H03B5/1231; H03B5/1203; H03B5/1237; H03B5/124; H03B5/1243; H03B2200/00; H03B2200/003; H03B2200/004; H03B2201/00; H03B2201/02; H03B2201/0208
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
158 words
In a television tuner tunable over a desired band of frequencies and including a mixer stage, an oscillator comprising: a transistor having a first electrode, a second electrode, and a control electrode; a source of operating potential; circuit means interconnecting the first electrode and the control electrode of said transistor with said source of operating potential; a source of tuning bias potential; tunable circuit means coupled to the first electrode of said transistor, including a voltage dependent variable capacitance diode which is conductive over a portion of said desired band of frequencies; a resistor interconnecting said voltage dependent variable capacitance diode and said tuning bias potential such that when said diode is conductive, a voltage is established across said resistor of a polarity that opposes the tuning bias potential; and an injection circuit interconnecting said mixer stage and said oscillator including a serially connected capacitor and inductor series resonant at a frequency within said desired band of frequencies.
Claim 2
Dependent Claim
158 words
In a television tuner tunable over a desired band of frequencies and including a mixer stage, an oscillator comprising: a transistor having a first electrode, a second electrode, and a control electrode; a source of operating potential; circuit means interconnecting the first electrode and the control electrode of said transistor with said source of operating potential; a source of tuning bias potential; tunable circuit means coupled to the first electrode of said transistor, including a voltage dependent variable capacitance diode which is conductive over a portion of said desired band of frequencies; a resistor interconnecting said voltage dependent variable capacitance diode and said tuning bias potential such that when said diode is conductive, a voltage is established across said resistor of a polarity that opposes the tuning bias potential; and an injection circuit interconnecting said mixer stage and said oscillator including a serially connected capacitor and inductor series resonant at a frequency within said desired band of frequencies.
Claim 3
Dependent Claim
74 words
In a television tuner tunable over a desired band of frequencies and including a mixer stage, an oscillator comprising: an oscillator transistor; a source of operating potential; circuit means interconnecting said transistor with said source of operating potential; tunable circuit means coupled to said transistor; and an injection circuit interconnecting said mixer stage and said oscillator including a serially connected capacitor and inductor series resonant at a frequency within said desired band of frequencies.
Claim 4
Dependent Claim
74 words
In a television tuner tunable over a desired band of frequencies and including a mixer stage, an oscillator comprising: an oscillator transistor; a source of operating potential; circuit means interconnecting said transistor with said source of operating potential; tunable circuit means coupled to said transistor; and an injection circuit interconnecting said mixer stage and said oscillator including a serially connected capacitor and inductor series resonant at a frequency within said desired band of frequencies.
Claim 5
Dependent Claim
32 words
An oscillator as defined in claim 2 wherein said series connected capacitor and inductor are series resonant at a frequency within a band of frequencies ranging from 88 MHz to 174 MHz.
Claim 6
Dependent Claim
26 words
An oscillator as defined claim 2 wherein said series connected capacitor and inductor are series resonant at an unused frequency within said band of desired frequencies.
Claim 7
Dependent Claim
62 words
An oscillator as defined in claim 4 further including a capacitor connected between said injection circuit and a point of fixed reference potential, said capacitor and said injection circuit forming a series resonant circuit between said mixer stage and said point of fixed reference potential which is resonant at a frequency above the frequency at which said injection circuit is series resonant.
Claim 8
Dependent Claim
135 words
In a television tuner tunable over a desired band of frequencies and including a mixer stage, an oscillator comprising: a transistor having a first electrode, a second electrode and a control electrode; a source of operating potential; circuit means interconnecting the first electrode and the control electrode of said transistor with said source of operating potential; a source of tuning bias potential; tunable circuit means coupled to the first electrode of said transistor, including a voltage dependent variable capacitance diode; means interconnecting said voltage dependent variable capacitance diode and said tuning bias potential; and an injection circuit iNterconnecting said mixer stage and the second electrode of said transistor, said injection circuit including a serially connected capacitor and inductor series resonant at a frequency within a band of frequencies ranging from 88 MHz to 174 MHz.
Claim 9
Dependent Claim
135 words
In a television tuner tunable over a desired band of frequencies and including a mixer stage, an oscillator comprising: a transistor having a first electrode, a second electrode and a control electrode; a source of operating potential; circuit means interconnecting the first electrode and the control electrode of said transistor with said source of operating potential; a source of tuning bias potential; tunable circuit means coupled to the first electrode of said transistor, including a voltage dependent variable capacitance diode; means interconnecting said voltage dependent variable capacitance diode and said tuning bias potential; and an injection circuit iNterconnecting said mixer stage and the second electrode of said transistor, said injection circuit including a serially connected capacitor and inductor series resonant at a frequency within a band of frequencies ranging from 88 MHz to 174 MHz.
Claim 10
Dependent Claim
64 words
An oscillator as defined in claim 6 further including a capacitor connected between said injection circuit and a point of fixed reference potential, said capacitor and said injection circuit forming a series resonant trap circuit between said mixer stage and said point of fixed reference potential which is series resonant at a frequency above the frequency at which said injection circuit is series resonant.
Claim 11
Dependent Claim
109 words
In a television tuner tunable over a desired band of frequencies and including a mixer stage, an oscillator comprising: a transistor having an emitter electrode, a collector electrode and a base electrode; a source of operating potential; circuit means interconnecting the collector electrode and the base electrode of said transistor with said source of operating potential; tunable circuit means coupled to the collector electrode of said transistor; and an injection circuit interconnecting said mixer stage and the emitter electrode of said transistor, said injection circuit including a serially connected capacitor and inductor series resonant at a frequency within a band of frequencies ranging from 88 MHz to 174 MHz.
Claim 12
Dependent Claim
109 words
In a television tuner tunable over a desired band of frequencies and including a mixer stage, an oscillator comprising: a transistor having an emitter electrode, a collector electrode and a base electrode; a source of operating potential; circuit means interconnecting the collector electrode and the base electrode of said transistor with said source of operating potential; tunable circuit means coupled to the collector electrode of said transistor; and an injection circuit interconnecting said mixer stage and the emitter electrode of said transistor, said injection circuit including a serially connected capacitor and inductor series resonant at a frequency within a band of frequencies ranging from 88 MHz to 174 MHz.
Claim 13
Dependent Claim
19 words
An oscillator as defined in claim 8 wherein said tunable circuit means includes a voltage dependent variable capacitance device.
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) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |