High-quality twisted-pair transmission line system for high-resolution video
View Patent ↗A system comprising a first filter having an input and an output adapted to compensate for the characteristics of a first length of twisted-pair wire is disclosed. A first bypass path has an input and an output for bypassing the first filter. A second filter has an input and an output adapted to compensate for the characteristics of a first length of twisted-pair wire. A second bypass path has an input and an output for bypassing the first filter. A third filter has an input and an output adapted to compensate for the characteristics of a first length of twisted-pair wire. A third bypass path has an input and an output for bypassing the first filter. The three filters can be configured form a signal path or one or more filters removed from the signal path by switching in bypass paths.
1. A transmission line filter system, comprising:
(a) a first filter having an input and an output adapted to compensate for the characteristics of a first length of twisted-pair wire;
(b) a first bypass path having an input and an output for bypassing said first filter;
(c) a second filter having an input and an output adapted to compensate for the characteristics of a second length of twisted-pair wire;
(d) a second bypass path having an input and an output for bypassing said first filter;
(e) a third filter having an input and an output adapted to compensate for the characteristics of a third length of twisted-pair wire;
(f) a third bypass path having an input and an output for bypassing said first filter;
(g) a coupling device for coupling an input high resolution video signal;
(h) a first input switch for connecting said coupling device to the input of said first filter or said first bypass path;
(i) a first output switch coupling the output of said first filter, when said first input switch is connecting said coupling device to the input of said first filter, or coupling said first bypass path when said first input switch is connecting said coupling device to said first bypass path;
(j) a second input switch for connecting said first output switch to the input of said second filter or said second bypass path;
(k) a second output switch coupling the output of said second filter, when said second input switch is connecting said first output switch to the input of said second filter, or coupling said second bypass path when said second input switch is connecting said first output switch to said second bypass path;
(l) a third input switch for connecting said second output switch to the input of said third filter or said third bypass path;
(m) a third output switch coupling the output of said third filter, when said third input switch is connecting said second output switch to the input of said third filter, or coupling said third bypass path when said third input switch is connecting said second output switch to said third bypass path; and
(n) an output coupling line coupled to receive the output from said third output switch.
2. A transmission line filter system as in claim 1 , further comprising a twisted-pair feed coupled to said coupling device.
3. A transmission line filter system as in claim 1 , wherein said second filter compensates for said second length and said first filter, and said first filter or said second filter is adjustable to compensate for the characteristics of a variable length of line.
4. A transmission line filter system as in claim 1 , wherein said second and third lengths are equal to each other.
5. A transmission line filter system as in claim 1 , wherein said third length is twice as long as said second length.
6. A transmission line system as in claim 1 , further comprising a clamping system coupling said third output switch to said output coupling line, said clamping system comprising a high-speed operational amplifier first clamp coupled to the output of said third output switch, the output of said operational amplifier first clamp being coupled to one end of a forward-biased semiconductor junction, the other end of said semiconductor junction being coupled to a second semiconductor clamp, said second semiconductor clamp having a second junction and exhibiting capacitance across said second junction, a third semiconductor clamp receiving the output of said second semiconductor clamp, said third semiconductor clamp being biased to cause a geometric increase in current flow through said third semiconductor clamp to regulate an undershoot condition at the output of said second semiconductor clamp.
7. A transmission line filter system as in claim 1 , further comprising a twisted-pair feed coupled to said coupling device, and wherein said second filter compensates for said second length and said first filter, and said first filter or said second filter is adjustable to compensate for the characteristics of a variable length of line.
8. A transmission line filter system as in claim 7 , wherein said second and third lengths are equal to each other.
9. A transmission line filter system as a claim 8 , wherein said filters are multiple filters, said filters comprising a plurality of resistor-capacitor networks.