Crosstalk canceling pattern for high-speed communications and modular jack having the same

• US 20060154531A1
• Filed: 01/09/2006
• Published: 07/13/2006
• Est. Priority Date: 01/11/2005
• Status: Active Grant

• Current Assignee: Dongbu Daewoo Electronics Corporation (Dayou Holdings Co.,Ltd.)
• Original Assignee: Daeun Electronics Company Limited
• Inventors: Lee, Jung Suk, Kim, Dae Sung, Kim, Su Jong, Kim, Jung Gon
• Granted Patent: US 7,175,476 B2
• Time in Patent Office: Days
• US Class Current: 439/676
• CPC Class Codes: H01R 13/6466 on substrates, e.g. printed circuit boards [PCB]
• CPC Class Codes: H01R 13/6473 Impedance matching
• CPC Class Codes: H01R 13/6658 on printed circuit board H01R13/6666 - H01R13/6691 take precedence
• CPC Class Codes: H01R 24/64 for high frequency, e.g. RJ 45
• CPC Class Codes: H05K 1/0228 Compensation of cross-talk by a mutually correlated lay-out of printed circuit traces, e.g. for compensation of cross-talk in mounted connectors balanced signal pairs H05K1/0245
• CPC Class Codes: H05K 1/162 incorporating printed capacitors
• CPC Class Codes: H05K 2201/09236 Parallel layout
• CPC Class Codes: H05K 2201/10189 Non-printed connector
• CPC Class Codes: Y10S 439/941 Crosstalk suppression

Abstract

Disclosed herein are a crosstalk canceling pattern for high-speed communications and a modular jack having the same, which includes a compensating capacitor on a transmission line to cancel crosstalk due to parasitic capacitance generated between neighboring insert pins, and includes a second compensating capacitor to correct phase mismatch due to parasitic inductance generated in insert pins and transmission lines, when a high-frequency signal is applied. The modular jack having the crosstalk canceling pattern for high-speed communications includes a housing, a printed circuit board, a lower contact block, and an upper contact block. The hosing includes a plug insert hole, an insert pin locking plate, and a coupling guide part. The printed circuit board is a multi-layered structure having a plurality of compensating capacitors. The lower contact block is mounted to the lower surface of the printed circuit board. The upper contact block is mounted to the upper portion of the lower contact block, and divides UTP cable wires to be connected to IDC terminals.

Claims

1. A modular jack having a crosstalk canceling pattern for high-speed communications, the modular jack comprising a plurality of insert pins electrically connected to a modular plug, a plurality of IDC terminals connected to an UTP cable, a printed circuit board connecting the insert pins to the IDC terminals via a transmission line, and a first compensating capacitor provided on a transmission line of the printed circuit board to compensate for first parasitic capacitance generated between the insert pins, wherein

first parasitic inductance generated in the insert pins and a transmission line between the insert pins and the first compensating capacitor, and second parasitic inductance generated in a transmission line between the first compensating capacitor and the IDC terminals are symmetrical with respect to the first compensating capacitor;

and

a second compensating capacitor, generating second compensating capacitance, is provided in a transmission line adjacent to the IDC terminals so as to correct phase mismatch, due to an increase in capacitance caused by the first compensating capacitor and an increase in the first and second parasitic inductance.

2. The modular jack as set forth in claim 1, wherein the modular jack is constructed so that generation of the first parasitic capacitance and the first parasitic inductance generated in front of the first compensating capacitor is limited to be as small as possible, thus allowing the first parasitic capacitance and the first parasitic inductance to be more easily symmetrical to the second parasitic inductance and the second compensating capacitance generated in back of the first compensating capacitance.

3. The modular jack as set forth in claim 1, wherein the insert pins are vertically installed in such a way as to be spaced apart from each other by a predetermined distance in front and rear directions, so that inclination angles of the neighboring insert pins are differently changed when the insert pins are pressed by the modular plug, and the insert pins are not arranged to be parallel to each other but are staggered.

4. The modular jack as set forth in claim 3, wherein each of the insert pins is formed to be as short as possible, thus minimizing the magnitude of the parasitic inductance generated in the insert pins.

5. The modular jack as set forth in claim 1, wherein the first compensating capacitor is installed as near the insert pins as possible, thus minimizing the magnitude of the first parasitic inductance generated in the transmission line between the insert pins and the first compensating capacitor.

6. The modular jack as set forth in claim 1, wherein the second parasitic inductance generated in the transmission line between the first compensating capacitor and the IDC terminals is symmetrical to the first parasitic inductance generated in front of the first compensating capacitor.

7. The modular jack as set forth in claim 1, wherein the printed circuit board comprises three substrates and four patterned layers, transmission lines extending from the insert pins to the IDC terminals are formed on an upper surface of an upper substrate and a lower surface of a lower substrate, and the first compensating capacitor for compensating the first parasitic capacitance generated in the insert pins and the second compensating capacitor for correcting phase mismatch due to compensating capacitance and parasitic inductance are provided on upper and lower surfaces of a middle substrate.

8. The modular jack as set forth in claim 7, wherein the upper and lower substrates are compressed to be secured to the upper and lower surfaces of the middle substrate, respectively.

9. The modular jack as set forth in claim 7, wherein the printed circuit board is made of a material having a dielectric constant of 3.0 or higher, thus preventing capacitive coupling in a high-frequency area.

10. The modular jack as set forth in claim 7, wherein the middle substrate has ample thickness of 1.6 mm or higher.

11. The modular jack as set forth in claim 1, comprising:

a housing into which a modular plug is inserted;

upper and lower contact blocks into which an UTP cable is introduced; and

a printed circuit board to connect insert pins, electrically connected to the modular plug, to a plurality of IDC terminals connected to the UTP cable via a transmission line, wherein

the housing comprises;

a plug insert hole formed in a front surface of the housing so that the modular plug is tightly inserted into the plug insert hole;

an insert pin locking plate provided on a lower portion of the plug insert hole so that the insert pins inserted through a rear portion of the housing are locked to the insert pin locking plate; and

a coupling guide part integrally provided on the rear portion of the housing, and having a size which is suitable for accommodating a lower surface of the lower contact block;

the insert pins are locked to the insert pin locking plate, and contact the transmission line of the printed circuit board along the shortest possible distance;

the printed circuit board comprises a multi-layered structure having a plurality of compensating capacitors, with the insert pins and the IDC terminals passing through the printed circuit board;

the lower contact block is coupled at a lower surface thereof to the printed circuit board, and comprises;

a plurality of through holes formed at positions corresponding to the IDC terminals; and

front and rear rib walls provided to be higher than the IDC terminals passing through the through holes and be lower than the front surface of the housing, so that the lower contact block is slidably coupled to the housing along the coupling guide part thereof; and

the upper contact block comprises;

an upper plate having a size suitable for covering the lower contact block; and

side plates having terminal insert holes so that the IDC terminals are inserted into the terminal insert holes, so that the upper contact plate divides wires of the UTP cable introduced through a rear portion of the upper contact block, and connect the wires to the IDC terminals.

12. The modular jack as set forth in claim 11, wherein each of the insert pins comprises:

an insert part having a length which is suitable for passing through the printed circuit board;

a protruding stop part stopped by an upper surface of the printed circuit board; and

a bent part provided on an upper end of the stop part.

13. The modular jack as set forth in claim 11, wherein the insert part of each of the insert pins passes vertically through an associated pin contact hole of the printed circuit board to be connected to the transmission line, the stop part of each of the insert pins is stopped by the upper surface of the printed circuit board in such a way as to be in surface contact with the printed circuit board, and the bent part of each of the insert pins is bent toward the rear portion of the housing and is inclined at a predetermined angle to be in surface contact with a terminal of the modular plug.

14. The modular jack as set forth in claim 11, wherein the coupling guide part of the housing comprises a “

U”

-shaped plate which is open at an upper portion thereof, with locking holes and slide grooves being formed on rear portions of side walls of the coupling guide part.

15. The modular jack as set forth in claim 11, wherein the insert pin locking plate has a height which is suitable for accommodating a length of the stop part of each of the insert pins, and is positioned to be perpendicular to the front surface of the housing, with deep pin guide grooves and shallow pin guide grooves being provided on a rear portion of the insert pin locking plate in such a way as to be staggered.

16. The modular jack as set forth in claim 11, wherein two rows of insert pins pass through pin contact holes formed in a front portion of an upper surface of the printed circuit board in such a way as to be spaced apart from each other in front and rear directions in a zigzag manner, and two rows of IDC terminals pass through terminal contact holes formed in left and right sides of a rear portion of the upper surface of the printed circuit board.

17. The modular jack as set forth in claim 16, wherein each of the IDC terminals comprises:

a contact part having a length which is suitable for passing through an associated terminal contact hole of the printed circuit board;

a terminal body extending from the contact part, having a locking part which protrudes to a side of the terminal body, and having a size to be accommodated in an associated through hole of the lower contact block; and

a cutter provided on an upper end of the terminal body and comprising two blades.

18. The modular jack as set forth in claim 11, wherein the lower contact block integrally comprises:

locking hooks protruding from both side surfaces thereof, and engaging with the locking holes of the housing;

a protruding guide part vertically provided on an inner surface of the front rib wall;

a lower cable insert hole formed in the rear rib wall, and having a size to allow the UTP cable to be introduced through the rear rib wall;

an upper block guide vertically formed on an inner surface of the rear rib wall; and

a block locking part provided at a position around the upper block guide, and engaging with a detachable hook of the upper contact block.

19. The modular jack as set forth in claim 11, wherein the lower contact block comprises a plurality of through holes, the size of an outlet of each of the through holes being set to allow the cutter of each of the IDC terminals to pass through the outlet and allow the locking part of the terminal body of each of the IDC terminals to be stopped by the outlet.

20. The modular jack as set forth in claim 11, wherein the upper contact block comprises:

the upper plate comprising a bent surface which is concave at an upper surface thereof;

a protective cover protruding from a front end of the upper plate;

a guide groove vertically formed on a front surface of the upper contact block;

the detachable hook provided on a rear portion of the upper contact block, and locked to the block locking part of the lower contact block;

an upper cable insert hole formed in a rear surface of the upper contact block so that the UTP cable is inserted into the upper cable insert hole;

wire insert holes formed on lower portions of both side plates of the upper contact block in such a way as to be perpendicular to the terminal insert holes, so that the wires of the cable inserted into the cable insert hole are inserted into the wire insert holes in diagonal directions; and

a protrusion protruding from a lower surface of the upper plate, and dividing the wires of the introduced UTP cable, to be inserted into the wire insert holes.

21. A crosstalk canceling pattern installed on a printed circuit board of a modular jack for high-speed communications and canceling crosstalk, wherein

the printed circuit board comprises three substrates, transmission lines extending from insert pins to IDC terminals are formed on an upper surface of an upper substrate and a lower surface of a lower substrate, and a first compensating capacitor for compensating for first parasitic capacitance generated in the insert pins and a second compensating capacitor for correcting phase mismatch due to compensating capacitance generated in the first compensating capacitor and parasitic inductance generated in the insert pins and the transmission lines are provided on upper and lower surfaces of a middle substrate.

22. The crosstalk canceling pattern as set forth in claim 21, wherein the first compensating capacitor is installed near the insert pins, and the second compensating capacitor is installed near the IDC terminals.

23. A crosstalk canceling pattern for high-speed communications, having a first compensating capacitor which generates inverse-phase compensating capacitance so as to offset parasitic capacitance generated between a plurality of insert pins, wherein

a second compensating capacitor is provided in back of the first compensating capacitor, and generates second compensating capacitance to correct phase mismatch due to parasitic capacitance and inductance generated in front of the first compensating capacitor, and

the magnitude of first parasitic capacitance and second parasitic inductance is minimized so that the first parasitic capacitance generated in front of the compensating capacitance and first parasitic inductance generated in the insert pins and a transmission line between the insert pins and the compensating capacitor, are symmetrical to second compensating capacitance generated in back of the compensating capacitance and second parasitic inductance generated in a transmission lines between the compensating capacitor and IDC terminals.