Patent ID: 7876172

Claim:
A balanced-unbalanced conversion element comprising: a dielectric substrate; a first ¼-wavelength resonant line on a surface of the dielectric substrate and coupled to a first balanced terminal to form a first ¼-wavelength resonator; a second ¼-wavelength resonant line on the surface of the dielectric substrate and coupled to a second balanced terminal to form a second ¼-wavelength resonator; and a ½-wavelength resonant line on the surface of the dielectric substrate, the ½-wavelength resonant line including a first open-end-side line coupled to an unbalanced terminal and the first ¼-wavelength resonator and a second open-end-side line coupled to the second ¼-wavelength resonator to form a ½-wavelength resonator, wherein a first gap between the first open-end-side line and the first ¼-wavelength resonant line is different from a second gap between the second open-end-side line and the second ¼-wavelength resonant line.