THREE-LINE BALUN TRANSFORMER

Japanese Patent JP3784782

B2

PROBLEM TO BE SOLVED: To provide a three-line balun transformer which is easy to design and is manufactured with a simple structure. SOLUTION: A balun transformer 50 is constituted of an unbalanced port 54 where an unbalanced signal is inputted or outputted, first and second balanced ports 55 and 56 where balanced signals and the like having a phase difference of 180° with equal magnitudes are outputted or inputted; a first line 51 having a first end connected to the unbalanced port 54 and a second end which is grounded; a second line 52 which is disposed in parallel with the first line 51 at a predetermined interval and has first and second ends, the second end being connected to the first balanced port 55; and a third line 53 which is disposed in parallel with the second line 52 at a predetermined interval, has a first end connected to the first end of the second line 52, and has a second end connected to the second balanced port 56.