US4498056A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal amplifier and integral signal shunt attenuator
Assignee: Motorola Solutions Inc
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Filing: 1983-07-28
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Granted: 1985-02-05
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Expires: 2003-07-28
Abstract
Abstract In accordance with the present invention there is provided an amplifier and integral signal shunt attenuator. The amplifier consists of an active amplifying device that is normally biased for signal amplification. The active amplifying device has a characteristic signal transfer impedance between its input and output and a characteristic signal shunt impedance across its input. The amplifier is configured such that the power dissipated by the active amplifying device may be limited. During transmission standby, the active amplifying device may be rebiased to lower the shunt impedance with respect to the transfer impedance. Thus, the undesirable signal is no longer fed-through the transfer impedance but is substantially shunted across the relatively low shunt impedance.
Inventors
- 👤 Peter A. Kwitkowski
- 👤 David R. Pacholok
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:22
CPC Classifications
H; H03; H03G; H03G1/00; H03G1/0005; H03G1/0035; H03G1/0082; H03G1/0017; H03G3/00; H03G3/20; H03G3/30; H03G3/3036; H03G3/3042
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
106 words
An amplifier and integral signal shunt attenuator, comprising: an amplifying device normally biased for signal amplification having means for inputting a signal and means for outputting an amplified signal, having a signal transfer impedance between the input and output means, and having a signal shunt impedance across the input means; means for disabling the amplifying function of the device; and means for rebiasing the device, whereby the device may be rebiased to lower the shunt impedance with respect to the transfer impedance such that an undesirable signal may no longer be fed-through the transfer impedance but may be substantially shunted across the relatively low shunt impedance.
Claim 2
Dependent Claim
106 words
An amplifier and integral signal shunt attenuator, comprising: an amplifying device normally biased for signal amplification having means for inputting a signal and means for outputting an amplified signal, having a signal transfer impedance between the input and output means, and having a signal shunt impedance across the input means; means for disabling the amplifying function of the device; and means for rebiasing the device, whereby the device may be rebiased to lower the shunt impedance with respect to the transfer impedance such that an undesirable signal may no longer be fed-through the transfer impedance but may be substantially shunted across the relatively low shunt impedance.
Claim 3
Dependent Claim
30 words
A signal shunt attenuator as claimed in claim 1 wherein the normally biased device further comprises: a semiconductor device having a semiconductor junction in shunt with the signal input means.
Claim 4
Dependent Claim
24 words
A signal shunt attenuator as claimed in claim 2 wherein the rebiasing means further comprises: means for heavily forward biasing the shunt semiconductor junction.
Claim 5
Dependent Claim
32 words
A signal shunt attenuator as claimed in claim 2 wherein the semiconductor device further comprises: one from the group of junction semiconductor devices including bipolar transistors, junction field effect transistors, and diodes.
Claim 6
Dependent Claim
26 words
A signal shunt attenuator as claimed in claim 1 wherein the amplification disabling means further comprises: means for removing the supply voltage applied to the device.
Claim 7
Dependent Claim
22 words
A signal shunt attenuator as claimed in claim 5 wherein the voltage removal means further comprises: means for removing the collector voltage.
Claim 8
Dependent Claim
23 words
A signal shunt attenuator as claimed in claim 1 wherein the amplification disabling means further comprises: means for limiting the amplifier current supply.
Claim 9
Dependent Claim
21 words
A signal shunt attenuator as claimed in claim 7 wherein the current limiting means further comprises: means for limiting collector current.
Claim 10
Dependent Claim
20 words
A signal shunt attenuator as claimed in claim 8 wherein the collector current limiting means further comprises: a collector resistor.
Claim 11
Dependent Claim
26 words
A signal shunt attenuator as claimed in claim 1 wherein the normally biased device further comprises: a normally biased bipolar transistor configured as a common-emitter amplifier.
Claim 12
Independent Claim
79 words
A method for shunting undesirable signal feed-through in an amplifier comprising: biasing an amplifying device for normal signal amplification, the device having a signal transfer impedance and a signal shunt impedance; disabling the amplifying function of the device; and rebiasing the device such that the shunt impedance becomes relatively low with respect to the transfer impedance, whereby an undesirable signal may no longer be fed-through the transfer impedance but may be substantially shunted across the relatively low shunt impedance.
Claim 13
Independent Claim
79 words
A method for shunting undesirable signal feed-through in an amplifier comprising: biasing an amplifying device for normal signal amplification, the device having a signal transfer impedance and a signal shunt impedance; disabling the amplifying function of the device; and rebiasing the device such that the shunt impedance becomes relatively low with respect to the transfer impedance, whereby an undesirable signal may no longer be fed-through the transfer impedance but may be substantially shunted across the relatively low shunt impedance.
Claim 14
Dependent Claim
27 words
A shunting method as claimed in claim 11 wherein the step of normally biasing a device further comprises: biasing a semiconductor junction in shunt with the signal.
Claim 15
Dependent Claim
21 words
A shunting method as claimed in claim 12 wherein the rebiasing step further comprises: heavily forward biasing the shunt semiconductor junction.
Claim 16
Dependent Claim
20 words
A shunting method as claimed in claim 11 wherein the amplification disabling step further comprises: removing the amplifier supply voltage.
Claim 17
Dependent Claim
20 words
A shunting method as claimed in claim 11 wherein the amplification disabling step further comprises: limiting the amplifier current supply.
References Cited (Backward Citations)
US3904977A
Cited
US4172999A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-05 | 1988-08-06 | 1989-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-05 | 1992-08-06 | 1993-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-05 | 1996-08-06 | 1997-02-05 | $7700.00 | Window Closed / Lapsed |