Pulse or digital communications – Repeaters – Testing
Patent
1987-09-23
1989-12-12
Safourek, Benedict V.
Pulse or digital communications
Repeaters
Testing
178 69N, 370 24, 379394, 357 12, H04B 304
Patent
active
048872784
ABSTRACT:
A post-equalizer and pre-equalizer circuit for use in communicating between nodes in a pulse amplitude modulated digital communication system is described. The post-equalizer circuit comprises a first variable zero circuit, a second variable circuit, and a gain shaper circuit wherein the gain and frequency location of the zeros in the zero circuits combined with the gain of the gain shaping circuit are simultaneously controlled by a control circuit which generates a control voltage which is a monotonically increasing function of cable loss. The control voltage generates a signal equal to the difference between the equalized signal and the original transmitted signal which is used to vary the resistance of voltage variable resistors in the form of FET's in each of the zero circuits and gain shaper circuits. If the cable loss is above a predetermined value, a pre-equalizer circuit is switched into the transmit path of the communication system and provides a gain, zero and pole at predetermined frequencies which pre-compensates for the extra loss incurred in transmission over length greater than can be equalized by the post-equalizer. Additionally, a bi-quad ACE circuit is described which provides a hyperbolic relationship between the zero frequency location and circuit gain utilizing a cascode amplifier and emitter follower circuit with a feedback loop through a voltage variable resistor.
REFERENCES:
patent: 2034703 (1936-03-01), Metzger
patent: 2236225 (1941-03-01), Thunell et al.
patent: 2522737 (1950-09-01), Bayard et al.
patent: 2678998 (1954-05-01), Young, Jr.
patent: 3151295 (1964-09-01), Haviland
patent: 3568100 (1971-03-01), Tarbox
patent: 3593142 (1971-07-01), Freeny et al.
patent: 3824501 (1974-07-01), Harris
patent: 4021738 (1977-05-01), Gitlin et al.
patent: 4227250 (1980-10-01), Wyner
patent: 4273963 (1981-06-01), Seidel
patent: 4493092 (1985-01-01), Adams
patent: 4507793 (1985-03-01), Adams
patent: 4550415 (1985-10-01), Debus, Jr., et al.
Integrated Network Corporation
Safourek Benedict V.
LandOfFree
Equalizer for digital transmission systems does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Equalizer for digital transmission systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Equalizer for digital transmission systems will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2126987