Patent ID: 7312683

Claim:
A symmetrical inductor, comprising: an insulating layer disposed on a substrate; first and second winding portions symmetrically arranged in the insulating layer, wherein each winding portion comprises first, second, third and fourth semi-circular conductive lines, and each semi-circular conductive line has a first end and a second end, wherein the first ends of the first and third semi-circular conductive lines of each winding portion are coupled to each other, the first ends of the second semi-circular conductive lines of the first and second winding portions are coupled to each other and the first ends of the fourth semi-circular conductive lines of the first and second winding portions are coupled to each other; and a first coupling portion disposed in the insulating layer between the first and second winding portions, comprising: a first pair of connection layers, wherein one of the first pair of connection layers is connected to the second ends of the first semi-circular conductive line of the first winding portion and the second semi-circular conductive line of the second winding portion, and the other one of the first pair of connection layers is connected to the second ends of the fourth semi-circular conductive line of the first winding portion and the third semi-circular conductive line of the second winding portion; and a second pair of connection layers, wherein one of the second pair of connection layers is connected to the second ends of the first semi-circular conductive line of the second winding portion and the second semi-circular conductive line of the first winding portion, and the other one of the second pair of connection layers is connected to the second ends of the fourth semi-circular conductive line of the second winding portion and the third semi-circular conductive line of the first winding portion; wherein one of the first and second pairs of the connection layers is upper cross-connections and the other pair is lower cross-connections.