Patent ID: 9083301
Filing Date: 2015-07-14
Classification: H03H

Abstract:
1. A balance filter comprising: an unbalanced terminal; a first balanced terminal; a second balanced terminal; a ground terminal; an unbalanced-side coupling coil; a balanced-side coupling coil electromagnetically coupled to the unbalanced-side coupling coil; and an unbalanced-side capacitor; wherein a first end of the unbalanced-side coupling coil is connected to the unbalanced terminal; a second end of the unbalanced-side coupling coil is connected to the ground terminal; a first end of the unbalanced-side capacitor is connected to the unbalanced terminal and a second end of the unbalanced-side capacitor is connected to the ground terminal, and an LC parallel resonant circuit is defined by the unbalanced-side capacitor and the unbalanced-side coupling coil; a first end of the balanced-side coupling coil is connected to the first balanced terminal, and a polarity of the first end of the balanced-side coupling coil is the same as a polarity of the first end of the unbalanced side coupling coil; a second end of the balanced-side coupling coil is connected to the second balanced terminal; and the second end of the unbalanced-side coupling coil is directly physically and electrically connected to the balanced-side coupling coil.