Abstract: A multilayer directional coupler which is easy to mass-produce and reduce in size, in which fine setting of the degree of electromagnetic coupling is facilitated, and which has a large bandwidth ratio, includes magnetic substrates, a laminate including first and second transformers, and external electrodes. One external electrode, which is connected to two ends of a primary coil of the first transformer, defines an input end for a main signal, and another external electrode defines an output end. A further external electrode, which is connected to two ends of a secondary coil of the second transformer, defines an output end for a sub-signal. A winding length ratio N1 of the secondary coil to primary coil of the first transformer and a winding length ratio N2 of the primary coil to secondary coil of the second transformer are each set to a value that is greater than about 1 and not greater than about 10. A ratio of the winding length ratio N2 to the winding length ratio N1 is greater than about 0.

Abstract: A laminated balun transformer that achieves improved balance characteristics and prevents the occurrence of parasitic inductance has an impedance transformation ratio of one to four and outputs balanced signals generated from an unbalanced signal. The laminated balun transformer includes a magnetic substrate, a laminated body, and external electrodes. The laminated body includes a first transformer, a second transformer, and a non-magnetic body which completely covers the first and second transformers from the outside. The first and second transformers are arranged side by side in a direction substantially parallel to the magnetic substrate. A primary coil of the first transformer and a secondary coil of the second transformer are configured to be 180-degree rotationally symmetric with respect to a center line, while a secondary coil and a primary coil are also configured to be 180-degree rotationally symmetric with respect to the center line L.

Abstract: A laminated balun transformer that achieves improved balance characteristics and prevents the occurrence of parasitic inductance has an impedance transformation ratio of one to four and outputs balanced signals generated from an unbalanced signal. The laminated balun transformer includes a magnetic substrate, a laminated body, and external electrodes. The laminated body includes a first transformer, a second transformer, and a non-magnetic body which completely covers the first and second transformers from the outside. The first and second transformers are arranged side by side in a direction substantially parallel to the magnetic substrate. A primary coil of the first transformer and a secondary coil of the second transformer are configured to be 180-degree rotationally symmetric with respect to a center line, while a secondary coil and a primary coil are also configured to be 180-degree rotationally symmetric with respect to the center line L.

Abstract: A multilayer directional coupler which is easy to mass-produce and reduce in size, in which fine setting of the degree of electromagnetic coupling is facilitated, and which has a large bandwidth ratio, includes magnetic substrates, a laminate including first and second transformers, and external electrodes. One external electrode, which is connected to two ends of a primary coil of the first transformer, defines an input end for a main signal, and another external electrode defines an output end. A further external electrode, which is connected to two ends of a secondary coil of the second transformer, defines an output end for a sub-signal. A winding length ratio N1 of the secondary coil to primary coil of the first transformer and a winding length ratio N2 of the primary coil to secondary coil of the second transformer are each set to a value that is greater than about 1 and not greater than about 10. A ratio of the winding length ratio N2 to the winding length ratio N1 is greater than about 0.