US3872393A
Expired / Lapsed
US
⏱️ 0.0 years remaining
If amplifier
Assignee: Sony Corp
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Filing: 1973-11-26
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Granted: 1975-03-18
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Expires: 1993-11-26
Abstract
Abstract An IF amplifier for FM radio receivers includes a differential amplifier in the final stage which has an IF tuning circuit for a load and an attenuator connected across the input circuit of the differential amplifier. The attenuator is provided to control the input signal applied to the differential amplifier in such a manner that the differential amplifier operates in a nonsaturating condition to reduce the distortion ratio.
Inventors
- 👤 Mitsuo Ohsawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 04:48
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/32; H03F1/3211; H03D; H03D3/00; H03D3/02; H03D3/06; H03D3/08; H03D3/10; H03F3/00; H03F3/189; H03F3/19; H03F3/191; H03F2203/00; H03F2203/45; H03F2203/45731
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
146 words
An IF amplifier comprising: a. a voltage source; b. a differential amplifier having first and second transistors whose emitter electrodes are connected to each other and to a voltage reference point through a common emitter impedance and whose collection electrodes are connected to the voltage source through a signal output means, a base electrode of said first transistor being supplied with an input signal, said differential amplifier being used as an IF final stage to which a frequency discriminator is connected; c. attenuating means consisting of first and second resistors and a first capacitor, said first resistor being connected between the base electrodes of said first and second transistor, said second resistor and first capacitor are connected in series between a base electrode of said second transistor and voltage reference point respectively, said means being of a value to keep the differential amplifier in nonsaturating condition.
Claim 2
Dependent Claim
146 words
An IF amplifier comprising: a. a voltage source; b. a differential amplifier having first and second transistors whose emitter electrodes are connected to each other and to a voltage reference point through a common emitter impedance and whose collection electrodes are connected to the voltage source through a signal output means, a base electrode of said first transistor being supplied with an input signal, said differential amplifier being used as an IF final stage to which a frequency discriminator is connected; c. attenuating means consisting of first and second resistors and a first capacitor, said first resistor being connected between the base electrodes of said first and second transistor, said second resistor and first capacitor are connected in series between a base electrode of said second transistor and voltage reference point respectively, said means being of a value to keep the differential amplifier in nonsaturating condition.
Claim 3
Dependent Claim
16 words
An IF amplifier according to claim 1, wherein the signal output means includes a tuning circuit.
Claim 4
Dependent Claim
40 words
An IF amplifier according to claim 2, which further includes a thrid transistor whose output terminal is connected to the base electrode of said first transistor, said third transistor being operative in a saturation condition to obtain a limiter effect.
Claim 5
Dependent Claim
34 words
An IF amplifier according to claim 2, wherein said tuning circuit comprises an LC resonance circuit which is connected to the collector electrodes of the first and second transistors as an unbalanced type load.
Claim 6
Dependent Claim
17 words
An IF amplifier according to claim 1, wherein said common emitter impedance comprising a constant current source.
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) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |