To provide a balanced transformer, which is miniaturized, widens a frequency band to be used and can prevent occurrence of migration.
Between an unbalanced terminal 11 and a dummy terminal 14, coils L1 and L2, having the same number of turns, are serially connected, between terminals 12 and 13 for balancing, coils L3 and L4, having the same number of turns, are connected and the node of both the coils is grounded. Also, between the terminal 11 for unbalancing and the ground, a coil L5 and a capacitor C4 are parallel-connected. Then, the coils L1 and L3 are coupled electromagnetically, and the coils L2 and L4 are coupled electromagnetically. Each of coils L1 and L2 or the like is configured, by overlapping the plural layers of conductor patterns printed on a dielectric insulating layer or the like and by linking them by means of a through-hole.
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