Patent ID: 8333599

Claim:
A modular jack, defining an input port and an output port with a plurality of transmission lines formed therebetween, comprising: an insulative housing defining a receiving space; a printed circuit board disposed within the receiving space; a plurality of transformer cores and a common mode choke core disposed on the printed circuit boards; a plurality of conductive wires respectively winding around the transformer cores to form primary coils and secondary coils of the transformers cores, each of the secondary coils having two opposite ends electrically connected to the output port, each of the primary coils having two opposite ends; and a plurality of conductive wires extending from said opposite ends of the primary coils of the transformer cores and winding around the common mode choke core to form a plurality of common mode coils, each common mode coil having one end connected to one end of the primary coil and an opposite end electrically connected to the input port; wherein each of the transmission lines comprises the primary coil and the secondary coil of one of the transformers and two of said common mode coils connected to opposite ends of corresponding primary coil; wherein the primary coil and the secondary coil in each transmission line share individual one of the transformer cores and the common mode coils in all transmission lines share said common mode choke core in common; wherein said printed circuit board has first and second ends, a first array of conductive pads arranged at the first end, and a second array of conductive pads arranged at the second end, the transformer cores and the common mode choke core interposed between the first and second arrays of the conductive pads; and wherein said common mode choke core defines two holes parallel extending therethrough and forming a center wall therebetween, the common mode coils winding around the center wall in a same direction.