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, the circuit board having first and second conductive layers separated from one another by a dielectric layer with conductive vias extending through the dielectric layer to provide electrical connections between the first and second conductive layers; and
a crosstalk compensation arrangement that provides crosstalk compensation between selected tracks of the circuit board, the crosstalk compensation arrangement including a zone of compensation including a capacitive coupling having a first capacitor plate defining a minor circular sector shape on the first conductive layer, and a second capacitor plate on the second conductive layer opposed to the first capacitor plate, the second capacitor plate defining a semicircular shape.
2. The telecommunications jack of claim 1 , wherein the zone of compensation is an unbalanced single zone of compensation.
3. The telecommunications jack of claim 2 , wherein the first conductive layer is on the first side.
4. The telecommunications jack of claim 2 , wherein the second conductive layer is between the first side and the second side.
5. The telecommunications jack of claim 1 , wherein the first and second capacitor plates at least partially overlap.
6. The telecommunications jack of claim 1 , further comprising at least one multi-zone compensation comprising a plurality of capacitive couplings between wire pairs.
7. The telecommunications jack of claim 6 , wherein the multi-zone compensation includes a first compensation zone a first time delay away from a capacitive coupling of the plug and a second compensation zone at a second time delay from the first compensation zone, the second compensation zone including two capacitive elements spaced at different time delays from the first compensation zone to optimize far end crosstalk and having an average time delay that optimizes near end crosstalk, wherein the capacitive coupling in the first compensation zone has an opposite polarity than the capacitive coupling in the plug, and wherein the capacitive coupling in the second compensation zone has the same polarity as the capacitive coupling in the plug.
8. The telecommunications jack of claim 7 , wherein the first compensation zone includes two capacitive elements that differ in magnitude.
9. The telecommunications jack of claim 7 , wherein the first and second zones of compensation are placed across the 3-6 and 4-5 wire pairs within the jack.
10. The telecommunications jack of claim 6 , wherein the multi-zone compensation includes:
a first coupling including first and second capacitive elements between two wire pairs of a jack, the first and second capacitive elements each having a differing magnitude of capacitive coupling to the two wire pairs to compensate for alien crosstalk; and
a second coupling including third and fourth capacitive elements between the two wire pairs of the jack at a second time delay from the first coupling, wherein the second time delay corresponds to an average time delay, and wherein different time delays of the third and fourth capacitive elements in the coupling are centered about the average time delay to optimize near end crosstalk and are spaced apart to reduce far end crosstalk.
11. The telecommunications jack of claim 6 , wherein the multi-zone compensation includes:
a first zone having an asymmetric capacitive coupling between two wire pairs, and a second zone with a polarity opposite the polarity of the first zone and having an asymmetric capacitive coupling between the two wire pairs, the first zone positioned nearer to the contact springs than the second zone, and wherein the first zone includes two capacitive elements that connect between different wires of one of the two wire pairs and the other of the two wire pairs, and wherein the two capacitive elements have different magnitudes.
12. The telecommunications jack of claim 11 , wherein the multi-zone compensation includes two zones of crosstalk compensation between a third wire pair, and one of the two wire pairs, and wherein at least one of the two zones has asymmetric capacitive coupling.
13. The telecommunications jack of claim 1 , wherein the unbalanced single zone of compensation is placed across the 1-2 and 4-5 wire pairs within the jack.