US3555303A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency converter circuit
Assignee: Hitachi Ltd
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Filing: 1968-02-28
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Granted: 1971-01-12
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Expires: 1988-02-28
Abstract
Abstract A frequency converter circuit in which the emitters of a pair of transistors are connected to each other to constitute a differential amplifier, said connected emitters being connected to a transistor which amplifies the input signal, one of said pair of transistors being comprised in a local oscillator circuit in which signal is fed back from the collector to the base, and output signal of the converter circuit being derived from the other one of said pair of transistors.
Inventors
- 👤 Tokinori Kozawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:57
CPC Classifications
H; H03; H03D; H03D7/00; H03D7/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
110 words
A frequency converter circuit comprising: a first transistor; means for supplying an input signal having a frequency fs to the base of said first transistor; second and third transistors the emitters of which are connected in common to the collector of said first transistor; a local oscillation frequency resonance circuit turned tuned to a frequency of fo and coupled between the collector and the base of said second transistor in feed back relation to form a local oscillator; and output means coupled to the collector of said third transistor for obtaining an output signal having a difference frequency between said input signal frequency fs and said local oscillation frequency fo.
Claim 2
Dependent Claim
110 words
A frequency converter circuit comprising: a first transistor; means for supplying an input signal having a frequency fs to the base of said first transistor; second and third transistors the emitters of which are connected in common to the collector of said first transistor; a local oscillation frequency resonance circuit turned tuned to a frequency of fo and coupled between the collector and the base of said second transistor in feed back relation to form a local oscillator; and output means coupled to the collector of said third transistor for obtaining an output signal having a difference frequency between said input signal frequency fs and said local oscillation frequency fo.
Claim 3
Dependent Claim
30 words
A frequency converter circuit according to claim 1, wherein said local oscillation frequency resonance circuit is connected to the base of said second transistor and coupled to the collector thereof.
Claim 4
Dependent Claim
30 words
A frequency converter circuit according to claim 1, wherein said local oscillation frequency resonance circuit is connected to the collector of said second transistor and coupled to the base thereof.
Claim 5
Dependent Claim
36 words
A frequency converter circuit according to claim 1, wherein a capacitor is connected between the base of said third transistor and ground, whereby the base of said third transistor is grounded with respect to AC signals.
Claim 6
Dependent Claim
48 words
A frequency converter circuit according to claim 1, further including means for supplying a DC voltage between the emitter of said first transistor and the colLectors of said second and third transistors and for supplying a DC voltage to the bases of said second and third transistors, respectively.
References Cited (Backward Citations)
US3219934A
Cited
US3284713A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-11 | 1974-07-13 | 1975-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-11 | 1978-07-13 | 1979-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-11 | 1982-07-13 | 1983-01-12 | $7700.00 | Window Closed / Lapsed |