Patent ID: 7663448
Filing Date: 2010-02-16
Classification: H01P

Abstract:
1. A laminated balun comprising: a dielectric member containing a plurality of laminated dielectric substrates; a balun section; and a matching circuit section, wherein the dielectric substrates include a first dielectric substrate, second dielectric substrate, third dielectric substrate, and fourth dielectric substrate which are sequentially arranged, the balun section has: a first earth electrode formed on a main surface of the first dielectric substrate; a second earth electrode formed on a main surface of the fourth dielectric substrate; a first transmission line which is formed on a main surface of the second dielectric substrate, one end of which is electrically connected to an unbalanced input/output terminal, and which has first and second portions; and second and third transmission lines on a main surface of the third dielectric substrate, the second transmission line being disposed so as to correspond to the first portion of the first transmission line and having one end thereof electrically connected to a first balanced input/output terminal, the third transmission line being disposed so as to correspond to the second portion of the first transmission line and having one end thereof electrically connected to a second balanced input/output terminal, and the matching circuit section is constituted by a patterned conductive film formed on the main surface of the third dielectric substrate or constituted by both a patterned conductive film formed on the main surface of the third dielectric substrate and the second earth electrode.