An inductor device includes a first trace, a second trace, and a capacitor. The first trace includes a first sub-trace and a second sub-trace. The first sub-trace and the second sub-trace form a plurality of first wires together at a first side of the inductor device, and form a plurality of second wires together at a second side of the inductor device. The second sub-trace is coupled to one terminal of the first sub-trace at a first node. The third sub-trace and the fourth sub-trace form a plurality of third wires together at the first side of the inductor device, and form a plurality of fourth wires together at the second side of the inductor device. The fourth sub-trace is coupled to one terminal of the third sub-trace at a second node. The capacitor is coupled to the first node and the second node.