US5295186A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Termination circuit for a two-wire transmission line
Assignee: NEC Corp
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Filing: 1990-04-13
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Granted: 1994-03-15
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Expires: 2010-04-13
Abstract
Abstract A low-pass filter is inserted between a two-wire line and a four-wire transmitting line for transmitting a transmission signal supplied from the two-wire line. Input and output signals of the low-pass filter are fedback to a subtracter to provide a subtracted signal which is added to an output signal of a terminal impedance resultant filter. Thus, operation is realized in a stable manner even in a high frequency band, in which an output signal of the low-pass filter is rotated in phase by 180°.
Inventors
- 👤 Toshiyuki Okamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:56
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/58; H04M1/585; H04B; H04B1/00; H04B1/38; H04B1/40; H04B1/54; H04B1/58; H04B1/586
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
163 words
A termination circuit for a two-wire transmission line, comprising: a low-pass filter connected in series to a four-wire transmitting line for transmitting a signal supplied from a two-wire transmission line; a serial connection of first to third adders and a reference resistance connected to a four-wire receiving line for supplying a receipt signal to said two-wire transmission line; a terminal impedance resultant filter including a switched capacitor and having an input terminal connected to an output terminal of said low-pass filter and an output terminal connected to an input terminal of said first adder; first and second feedback lines having first and second feedback amounts and connected to an input terminal and an output terminal of said low-pass filter, respectively; a subtractor having first and second input terminals connected to said first and second feedback lines, respectively and an output terminal connected to said second adder; and a third feedback line having one end connected to said input terminal of said low-pass filter.
Claim 2
Dependent Claim
163 words
A termination circuit for a two-wire transmission line, comprising: a low-pass filter connected in series to a four-wire transmitting line for transmitting a signal supplied from a two-wire transmission line; a serial connection of first to third adders and a reference resistance connected to a four-wire receiving line for supplying a receipt signal to said two-wire transmission line; a terminal impedance resultant filter including a switched capacitor and having an input terminal connected to an output terminal of said low-pass filter and an output terminal connected to an input terminal of said first adder; first and second feedback lines having first and second feedback amounts and connected to an input terminal and an output terminal of said low-pass filter, respectively; a subtractor having first and second input terminals connected to said first and second feedback lines, respectively and an output terminal connected to said second adder; and a third feedback line having one end connected to said input terminal of said low-pass filter.
Claim 3
Dependent Claim
26 words
A termination circuit for a two-wire transmission line, according to claim 1, wherein: said first and second feedback lines have a feedback amount of "1", respectively.
Claim 4
Dependent Claim
39 words
A termination circuit for a two-wire transmission line, according to claim 1, wherein: said first and second feedback lines have feedback amounts of K 1 and K 2 , where said K 1 and K 2 are arbitrary values.
References Cited (Backward Citations)
US4532384A
Cited
US4633225A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-03-14 | 1997-09-13 | 1998-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-14 | 2001-09-13 | 2002-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-03-14 | 2005-09-13 | 2006-03-15 | $7700.00 | Window Closed / Lapsed |