Patent ID: 7183872
Filing Date: 2007-02-27
Classification: H01P

Abstract:
1. A laminated balun transformer including a dielectric block formed by laminating a plurality of dielectric sheets, and a plurality of external electrodes formed on outer sides of the dielectric block, the plurality of external electrodes being used for a ground, input/output of an unbalanced signal, input/output of first and second balanced signals, and non-connection, wherein the dielectric block comprises; a first strip line having one end connected to the external electrode for input/output of the unbalanced signal; a second strip line having one end connected to the other end of the first strip line, the other end of the second strip line being opened; a third strip line formed in parallel with the first strip line, one end of the third strip line being connected to the external electrode for a ground and the other end of the third strip line being connected to the external electrode for input/output of the first balanced signal; a fourth strip line formed in parallel with the second strip line, one end of the fourth strip line being connected to the external electrode for a ground and the other end of the fourth strip line being connected to the external electrode for input/output of the second balanced signal; and a capacitance forming electrode formed in parallel with a portion of the other opened end of the second strip line and having one end connected to the external electrode for input/output of the unbalanced signal for forming a capacitance in parallel with the first and second strip lines, wherein the first to fourth strip lines are formed on different planes, and wherein the dielectric block further comprises a ground electrode connected to the external electrode for a ground for forming an electrical shielding between the first and third strip lines and the second and fourth strip lines in parallel with each other.