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Patent US5694439A successfully refreshed from Google Patents.
US5694439A
Expired / Lapsed
US
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Bi-directional low pass filtering method and apparatus
Assignee: Intel Corp
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Filing: 1995-03-21
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Granted: 1997-12-02
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Expires: 2015-03-21
Abstract
Abstract The present invention provides a bi-directional low pass filtering method and apparatus for attenuating out-of-baseband components of data transmitted from an encoder to a decoder over a transmission medium. In one embodiment of the present invention, the bi-directional low pass filtering apparatus includes a Chebyshev filter that has a first phase response. This Chebyshev filter is coupled to a phase correction circuit, which has a second phase response. This second phase response of the phase correction circuit is designed to oppose the first phase response in order to offset variations in group delay in the data due to the Chebyshev filter.
Inventors
- 👤 James T. Doyle
- 👤 Carl F. Liepold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:12
CPC Classifications
H; H03; H03H; H03H7/00; H03H7/01; H03H7/17; H03H7/1741; H03H7/1766; H03F; H03F3/00; H03F3/45; H03F3/45071; H03F3/45076; H03F3/4508; H03F3/45085; H03H11/00; H03H11/02; H03H11/04; H03H11/0422; H03H11/0444; H03H11/045; H03H7/0115; H04; H04L; H04L25/00; H04L25/02; H04L25/03; H04L25/03006; H04L25/03343; H04L5/00; H04L5/14; H04L5/16; H03F2203/00; H03F2203/45; H03F2203/45371; H03F2203/45574; H03F2203/45612
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
118 words
An encoder for transmitting data to a decoder over a transmission medium, the encoder comprising: a) a modulator for encoding a data bit stream supplied by a data source into a plurality of data symbol pulses; and b) a bi-directional low pass filter receiving said data symbol pulses, said low pass filter for filtering out out-of-baseband frequency components of said symbol pulses, said bi-directional low pass filter including: a Chebyshev filter having a first phase response, phase correction circuit coupled to said Chebyshev filter, said phase correction circuit having a second phase response, said second phase response opposing said first phase response in order to oppose variations in group delay of said data due to said Chebyshev filter.
Claim 2
Dependent Claim
118 words
An encoder for transmitting data to a decoder over a transmission medium, the encoder comprising: a) a modulator for encoding a data bit stream supplied by a data source into a plurality of data symbol pulses; and b) a bi-directional low pass filter receiving said data symbol pulses, said low pass filter for filtering out out-of-baseband frequency components of said symbol pulses, said bi-directional low pass filter including: a Chebyshev filter having a first phase response, phase correction circuit coupled to said Chebyshev filter, said phase correction circuit having a second phase response, said second phase response opposing said first phase response in order to oppose variations in group delay of said data due to said Chebyshev filter.
Claim 3
Dependent Claim
24 words
The encoder of claim 1, wherein said encoder further comprises a transmitter, said transmitter using a transmission medium to transmit data to a receiver.
Claim 4
Dependent Claim
20 words
The encoder of claim 1, wherein said modulator is coupled to said Chebyshev filter of said bi-directional low pass filter.
Claim 5
Dependent Claim
21 words
The encoder of claim 1, wherein said modulator is coupled to said phase correction circuit of said bi-directional low pass filter.
Claim 6
Dependent Claim
16 words
The encoder of claim 1, wherein said bi-directional low pass filter is implemented with discrete components.
Claim 7
Dependent Claim
16 words
The encoder of claim 1, wherein said bi-directional low pass filter is implemented with integrated circuits.
Claim 8
Dependent Claim
49 words
The encoder of claim 6, wherein said bi-directional low pass filter comprises: a switching network, said switching network enabling said bi-directional low pass filter to operate in a bi-directional manner; a voltage-to-current converter; a plurality of bi-quadratic filters, said bi-quadratic filters attenuating out-of-baseband data components, an all pass filter.
Claim 9
Dependent Claim
15 words
The encoder of claim 7, wherein said plurality of bi-quadratic filters are two pole filters.
Claim 10
Dependent Claim
121 words
An encoder for transmitting data to a decoder over a transmission medium, said encoder comprising: a) a modulator for encoding a data bit stream supplied by a data source into a plurality of data symbol pulses; and b) a bi-directional low pass filter receiving said data symbol pulses, said low pass filter for filtering out out-of-baseband frequency components of said symbol pulses, said bi-directional low pass filter including: a modified Chebyshev filter having a first phase response, phase correction circuit coupled to said modified Chebyshev filter, said phase correction circuit having a second phase response, said second phase response opposing said first phase response in order to oppose variations in group delay of said data due to said modified Chebyshev filter.
Claim 11
Dependent Claim
121 words
An encoder for transmitting data to a decoder over a transmission medium, said encoder comprising: a) a modulator for encoding a data bit stream supplied by a data source into a plurality of data symbol pulses; and b) a bi-directional low pass filter receiving said data symbol pulses, said low pass filter for filtering out out-of-baseband frequency components of said symbol pulses, said bi-directional low pass filter including: a modified Chebyshev filter having a first phase response, phase correction circuit coupled to said modified Chebyshev filter, said phase correction circuit having a second phase response, said second phase response opposing said first phase response in order to oppose variations in group delay of said data due to said modified Chebyshev filter.
Claim 12
Dependent Claim
24 words
The encoder of claim 9, wherein said encoder further comprises a transmitter, said transmitter using a transmission medium to transmit data to a receiver.
Claim 13
Dependent Claim
20 words
The encoder of claim 9, wherein said modulator is coupled to said Chebyshev filter of said bi-directional low pass filter.
Claim 14
Dependent Claim
21 words
The encoder of claim 9, wherein said modulator is coupled to said phase correction circuit of said bi-directional low pass filter.
Claim 15
Dependent Claim
16 words
The encoder of claim 9, wherein said bi-directional low pass filter is implemented with discrete components.
Claim 16
Dependent Claim
16 words
The encoder of claim 9, wherein said bi-directional low pass filter is implemented with integrated circuits.
Claim 17
Dependent Claim
49 words
The encoder of claim 14, wherein said bi-directional low pass filter comprises: a switching network, said switching network enabling said bi-directional low pass filter to operate in a bi-directional manner; a voltage-to-current converter; a plurality of bi-quadratic filters, said bi-quadratic filters attenuating out-of-baseband data components, an all pass filter.
Claim 18
Dependent Claim
15 words
The encoder of claim 15, wherein said plurality of bi-quadratic filters are two pole filters.
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) | 2000-12-01 | 2001-06-02 | 2001-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-12-01 | 2005-06-02 | 2005-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-12-01 | 2009-06-02 | 2009-12-02 | $7700.00 | Window Closed / Lapsed |