US3774118A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Line amplifier
Assignee: US Philips Corp
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Filing: 1972-03-20
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Granted: 1973-11-20
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Expires: 1992-03-20
Abstract
Abstract A line amplifier constituted by a transistor amplifier comprising a plurality of stages a number of which is locally fed back by a feedback impedance incorporated in the emitter circuit of these stages, and provided with a level control device which is constituted by these feedback impedances which to this end are each formed as controllable capacitive two-terminal networks the control members of which consist of voltage-dependent diodes arranged pairwise in a push-pull configuration, and a control voltage distribution network which distributes the control voltage applied thereto over the diode pairs in such a manner that the ratio between the time constants of the capacitive twoterminal networks remains substantially constant when the control voltage varies.
Inventors
- 👤 Doorn W Van
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:55
CPC Classifications
H; H03; H03G; H03G1/00; H03G1/0005; H03G1/0035; H03G1/0052; H03G1/0064; H04; H04B; H04B3/00; H04B3/02; H04B3/04; H04B3/10; H04B3/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
157 words
A line amplifier for use in a transmission system for transmitting signals in a board frequency band, comprising: a plurality of cascaded transistor amplifying stages at least two of which each have a frequency compensation impedence network in the emitter circuit thereof to compensate for frequency dependent signal losses, said networks each including at least one voltage controlled capacitance element; means for generating an amplification control voltage; a voltage dividing network responsive to said amplification control voltage for generating a capacitance control voltage for each of said voltage controlled capacitances and for applying said capacitance control voltages thereto, said capacitance control voltages remaining in substantially constant ratios with one another and with said amplification control voltage, thereby resulting in substantially constant ratios between the time constants associated with said capacitances and a substantially fixed though shifting frequency response curve for said amplifier over said broad band with the overall gain being controlled by said amplification control voltage.
Claim 2
Dependent Claim
157 words
A line amplifier for use in a transmission system for transmitting signals in a board frequency band, comprising: a plurality of cascaded transistor amplifying stages at least two of which each have a frequency compensation impedence network in the emitter circuit thereof to compensate for frequency dependent signal losses, said networks each including at least one voltage controlled capacitance element; means for generating an amplification control voltage; a voltage dividing network responsive to said amplification control voltage for generating a capacitance control voltage for each of said voltage controlled capacitances and for applying said capacitance control voltages thereto, said capacitance control voltages remaining in substantially constant ratios with one another and with said amplification control voltage, thereby resulting in substantially constant ratios between the time constants associated with said capacitances and a substantially fixed though shifting frequency response curve for said amplifier over said broad band with the overall gain being controlled by said amplification control voltage.
Claim 3
Dependent Claim
22 words
A line amplifier as claimed in claim 1 wherein said voltage controlled capacitances are pairs of varactor diodes arranged in push-pull configuration.
Claim 4
Dependent Claim
25 words
A line amplifier as claimed in claim 1 wherein at least one of said frequency compensation impedance networks includes more than one voltage controlled capacitance.
Claim 5
Dependent Claim
23 words
A line amplifier as claimed in claim 1 wherein said amplification control voltage is generated from a signal transmitted over said transmission system.
Claim 6
Dependent Claim
23 words
A line amplifier as claimed in claim 1 further characterized by signal feedback means connected between the first and last cascaded amplifying stages.
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) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |