US3581122A
Expired / Lapsed
US
⏱️ 0.0 years remaining
All-pass filter circuit having negative resistance shunting resonant circuit
Assignee: AT&T Inc
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Filing: 1967-10-26
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Granted: 1971-05-25
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Expires: 1987-10-26
Abstract
Abstract A transistor circuit having a constant amplitude vs frequency response is described. The required transfer function is obtained by connecting a negative resistance across a resonant network in the transistor circuit. This arrangement provides a pole-zero pattern in the complex plane representation which is symmetrical with respect to the imaginary axis whereby the absolute magnitude of the ratio of output signal to input signal is constant for all frequencies.
Inventors
- 👤 Wilmer B Gaunt Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:02
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/16; H03H11/18; H03H11/04; H03H11/12; H03H11/1213; H03H11/126; H03H11/22
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
79 words
A transmission circuit coMprising an amplifying device having first, second and third electrodes, means for applying a signal to said second electrode, and means responsive to said signal for producing an output signal at said third electrode comprising resonant network means connected to said first electrode and negative impedance means connected across said resonant network means, said resonant network comprising resistance means and said negative impedance means comprising a negative resistance having twice the value of said resistance means.
Claim 2
Dependent Claim
79 words
A transmission circuit coMprising an amplifying device having first, second and third electrodes, means for applying a signal to said second electrode, and means responsive to said signal for producing an output signal at said third electrode comprising resonant network means connected to said first electrode and negative impedance means connected across said resonant network means, said resonant network comprising resistance means and said negative impedance means comprising a negative resistance having twice the value of said resistance means.
Claim 3
Dependent Claim
39 words
A transmission circuit according to claim 1 wherein said resonant network means comprises a series resonant circuit and said amplifying device comprises a transistor having emitter, base and collector electrodes corresponding to said first, second and third electrodes, respectively.
Claim 4
Dependent Claim
24 words
A transmission circuit according to claim 2 wherein said series resonant circuit comprises a capacitor and an inductor connected serially with said resistance means.
Claim 5
Dependent Claim
107 words
In an all-pass filter, in combination, an amplifying device having input, output and control electrodes, means for applying a first signal to said control electrode, and means connected to said input electrode for producing a second signal at said output electrode responsive to said first signal, the absolute magnitude of the ratio of said second signal to said first signal being invariant with frequency, said means connected to said input electrode comprising resonant network means including positive resistance means and negative resistance means connected across said resonant network means, said negative resistance means having a negative resistance value of twice the value of said positive resistance means.
Claim 6
Dependent Claim
107 words
In an all-pass filter, in combination, an amplifying device having input, output and control electrodes, means for applying a first signal to said control electrode, and means connected to said input electrode for producing a second signal at said output electrode responsive to said first signal, the absolute magnitude of the ratio of said second signal to said first signal being invariant with frequency, said means connected to said input electrode comprising resonant network means including positive resistance means and negative resistance means connected across said resonant network means, said negative resistance means having a negative resistance value of twice the value of said positive resistance means.
Claim 7
Dependent Claim
121 words
In a signal transmission system, a plurality of transmission circuits each comprising an amplifying device having input, output and control electrodes, means for applying an input signal to said control electrode, and means responsive to said input signal for producing a signal at said output electrode comprising resonant network means including positive resistance means connected to said input electrode and a negative resistance having twice the value of said positive resistance means connected across said resonant network means, and means for applying a common signal to each of said transmission circuits, said resonant network means in each of said transmission circuits comprising means for providing a signal at the corresponding output electrode having a distinct phase response to said common signal.
Claim 8
Dependent Claim
121 words
In a signal transmission system, a plurality of transmission circuits each comprising an amplifying device having input, output and control electrodes, means for applying an input signal to said control electrode, and means responsive to said input signal for producing a signal at said output electrode comprising resonant network means including positive resistance means connected to said input electrode and a negative resistance having twice the value of said positive resistance means connected across said resonant network means, and means for applying a common signal to each of said transmission circuits, said resonant network means in each of said transmission circuits comprising means for providing a signal at the corresponding output electrode having a distinct phase response to said common signal.
Claim 9
Dependent Claim
62 words
In a signal transmission system, a plurality of transmission circuits according to claim 5 wherein said means for providing a signal at the corresponding output electrode having a distinct phase response to said common signal comprises means for providing a phase response to said common signal different from the phase response of each of the other of said plurality of transmission circuits.
Claim 10
Dependent Claim
73 words
In a signal transmission system, a plurality of transmission circuits according to claim 6 wherein said plurality of transmission circuits comprises a pair of transmission circuits, and the resonant network means of one of said pair of transmission circuits comprises mean for providing a signal at the corresponding output electrode having a phase response to said common signal in quadrature with the phase response of the other of said pair of transmission circuits.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |