Multistage capacitive crosstalk compensation arrangement
Methods and systems for providing crosstalk compensation in a jack are disclosed. According to one method, the crosstalk compensation is adapted to compensate for undesired crosstalk generated at a capacitive coupling located at a plug inserted within the jack. The method includes positioning a first capacitive coupling a first time delay away from the capacitive coupling of the plug, the first capacitive coupling having a greater magnitude and an opposite polarity as compared to the capacitive coupling of the plug. The method also includes positioning a second capacitive coupling at a second time delay from the first capacitive coupling, the second time delay corresponding to an average time delay that optimizes near end crosstalk. The second capacitive coupling has generally the same overall magnitude but an opposite polarity as compared to the first capacitive coupling, and includes two capacitive elements spaced at different time delays from the first capacitive coupling.
1. A telecommunications jack for use in a twisted pair system, the jack comprising:
a housing defining a port for receiving a plug;
a plurality of contact springs adapted to make electrical contact with the plug when the plug is inserted into the port of the housing;
a plurality of wire termination contacts for terminating wires to the jack;
a circuit board including conductive tracks that electrically connect the contact springs to the wire termination contacts, the circuit board having a first side and an opposite second side, wherein the plurality of contact springs extend from the first side of the circuit board and the plurality of wire termination contacts extend from the second side of the circuit board; and
means for crosstalk compensation between selected tracks of the circuit board including asymmetric capacitive coupling between a first wire pair and a second wire pair.
2. The telecommunications jack of claim 1 , wherein the means for crosstalk compensation includes a first zone of compensation a first time delay away from the capacitive coupling of the plug and a second zone of compensation at a second time delay from the first zone of compensation.
3. The telecommunications jack of claim 2 , wherein the means for crosstalk compensation includes two capacitive elements spaced at different time delays from the first zone of compensation to optimize far end crosstalk and having an average time delay that optimizes near end crosstalk.
4. The telecommunications jack of claim 2 , wherein the-capacitive coupling in the first zone of compensation has an opposite polarity than the capacitive coupling in the plug, and wherein capacitive coupling in the second zone of compensation has the same polarity as the capacitive coupling in the plug.
5. The telecommunications jack of claim 2 , wherein the second zone of compensation includes two capacitive elements that connect between different wires of the first wire pair and the second wire pair.
6. The telecommunications jack of claim 5 , wherein the means for crosstalk compensation includes two zones of crosstalk compensation between a third wire pair, and one of the first or second wire pairs, and wherein at least one of the two zones has asymmetric capacitive coupling.
7. The telecommunications jack of claim 5 , wherein the first wire pair is a 3-6 wire pair and the second wire pair is a 4-5 wire pair.
8. A telecommunications jack with a plurality of wire pairs for use in a twisted pair system, the jack comprising:
a housing defining a port for receiving a plug;
a plurality of contact springs adapted to make electrical contact with the plug when the plug is inserted into the port of the housing;
a plurality of wire termination contacts for terminating wires to the jack;
a circuit board including conductive tracks that electrically connect the contact springs to the wire termination contacts; and
means for crosstalk compensation including asymmetric capacitive coupling between a first wire pair and a second wire pair.
9. The telecommunications jack of claim 8 , wherein the means for crosstalk compensation includes a first zone having the asymmetric capacitive coupling between the first wire pair and the second wire pair, and a second zone with capacitive coupling between the first pair and the second pair and having a polarity opposite the polarity of the first zone.
10. The telecommunications jack of claim 9 , wherein the first zone is positioned nearer to the contact springs than the second zone.
11. The telecommunications jack of claim 9 , wherein the first zone includes two capacitive elements that connect between different wires of the first wire pair and the second wire pair.
12. The telecommunications jack of claim 11 , wherein the two capacitive elements have different magnitudes.
13. The telecommunications jack of claim 11 , wherein the second zone includes two capacitive elements that connect between different wires of the first wire pair and the second wire pair.
14. The telecommunications jack of claim 13 , wherein the second zone has asymmetric capacitive coupling, and wherein the two capacitive elements in the second zone have different magnitudes.
15. The telecommunications jack of claim 8 , wherein the means for crosstalk compensation is entirely on the circuit board.