Marchand balun formed in a laminated substrate and including main lines and sub-lines formed by partial lines having specified distance relationships

A balun comprising:

• a dielectric substrate in which a plurality of dielectric layers are laminated;
• an unbalanced terminal, a first balanced terminal, a second balanced terminal, and a reference potential terminal on the dielectric substrate;
• a first main line having a first end that is connected to the unbalanced terminal;
• a second main line having a first end that is connected to a second end of the first main line, and having a second end that is open;
• a first sub-line connected between the first balanced terminal and the reference potential terminal;
• and
• a second sub-line connected between the second balanced terminal and the reference potential terminal,
• wherein in the dielectric substrate, the first main line, the first sub-line, the second sub-line, and the second main line are arranged sequentially in a laminating direction,
• wherein the second sub-line comprises a first partial line connected to the second balanced terminal, and a second partial line connected between the first partial line and the reference potential terminal, and
• wherein the first partial line is on a first dielectric layer between a second dielectric layer having the second partial line and a third dielectric layer having the second main line.