US4017687A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for minimizing interchannel crosstalk in high rate commutator multiplexers
Assignee: United States Department of the Navy
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Filing: 1975-11-28
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Granted: 1977-04-12
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Expires: 1995-11-28
Abstract
Abstract A switching system for use in conjunction with a high rate commutator mullexer which separates the commutator switches into two groups. During alternating off periods, each group is grounded through a switch such that voltage which is built up on the inherent capacitances of the commutator switches is reduced to zero. In this manner, crosstalk is virtually eliminated between channels of the commutator.
Inventors
- 👤 Franklin R. Hartzler
- 👤 Michael V. Wechsler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:12
CPC Classifications
H; H04; H04J; H04J3/00; H04J3/02; H04J3/10
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
160 words
A device for minimizing interchannel crosstalk in a high rate commutator multiplexer comprising: a. a first subgroup of commutative switches connected in parallel; b. a second subgroup of commutative switches connected in parallel; c. first switching means connected to said first subgroup of commutative switches for periodically connecting said first subgroup to an output in accordance with a first predetermined switching pattern; d. second switching means connected to said second subgroup of commutative switches for periodically connecting said second subgroup to said output in accordance with a second predetermined switching pattern; e. means for periodically grounding said first subgroup of commutative switches in accordance with said second predetermined switching pattern; f. means for periodically grounding said second subgroup of commutative switches in accordance with said first predetermined switching pattern; g. wherein said first subgroup and said second subgroup of commutative switches are alternatively grounded to discharge voltage accumulated due to inherent capacitance in said commutative switches, thereby minimizing interchannel crosstalk.
Claim 2
Independent Claim
160 words
A device for minimizing interchannel crosstalk in a high rate commutator multiplexer comprising: a. a first subgroup of commutative switches connected in parallel; b. a second subgroup of commutative switches connected in parallel; c. first switching means connected to said first subgroup of commutative switches for periodically connecting said first subgroup to an output in accordance with a first predetermined switching pattern; d. second switching means connected to said second subgroup of commutative switches for periodically connecting said second subgroup to said output in accordance with a second predetermined switching pattern; e. means for periodically grounding said first subgroup of commutative switches in accordance with said second predetermined switching pattern; f. means for periodically grounding said second subgroup of commutative switches in accordance with said first predetermined switching pattern; g. wherein said first subgroup and said second subgroup of commutative switches are alternatively grounded to discharge voltage accumulated due to inherent capacitance in said commutative switches, thereby minimizing interchannel crosstalk.
Claim 3
Dependent Claim
22 words
The device of claim 1 wherein said means for periodically grounding said first subgroup and said second subgroup comprises a semiconductor switch.
Claim 4
Dependent Claim
30 words
The device of claim 1 wherein signal conditioning networks connected to said commutative switches comprise an resistive network having a high output impedance with a minimum of crosstalk between channels.
Claim 5
Dependent Claim
22 words
The device of claim 3 wherein said means for periodically grounding said first subgroup and said second subgroup comprises a semiconductor switch.
Claim 6
Independent Claim
63 words
A device for reducing crosstalk between channels of a rapid commutator multiplexer commutator comprising: a. means for alternatively switching two subgroups of commutative switches to a single output; b. means for grounding said commutative switches whenever said commutative switches are not connected to said output to provide a means for discharging inherent capacitance in said commutative switches and thereby reduce crosstalk between channels.
Claim 7
Independent Claim
63 words
A device for reducing crosstalk between channels of a rapid commutator multiplexer commutator comprising: a. means for alternatively switching two subgroups of commutative switches to a single output; b. means for grounding said commutative switches whenever said commutative switches are not connected to said output to provide a means for discharging inherent capacitance in said commutative switches and thereby reduce crosstalk between channels.
Claim 8
Dependent Claim
30 words
The device of claim 5 wherein signal conditioning networks connected to said commutative switches comprise an resistive network having a high output impedance with a minimum of crosstalk between channels.
Claim 9
Dependent Claim
14 words
The device of claim 5 wherein said means for grounding comprises a semiconductor switch.
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) | 1980-04-11 | 1980-10-11 | 1981-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-11 | 1984-10-11 | 1985-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-11 | 1988-10-11 | 1989-04-12 | $7700.00 | Window Closed / Lapsed |