Band-pass filter having three or more loop-shaped electrodes

摘要

Three coil electrode patterns are formed on one surface of a plate containing of a dielectric material. These coil electrode patterns are formed in loop shape, and are disposed in a magnetically connecting state with respect to each other. An input/output terminal pattern and an earth terminal pattern are drawn out from each of the two coil electrode patterns which are disposed toward the end portions of the plate. The input/output terminal pattern and the earth terminal pattern are disposed at a distance for each other so as to provide a predetermined impedance. An earth electrode pattern is drawn out from the center coil electrode pattern. An earth electrode pattern is formed opposite the coil electrode patterns with the plate between them. Earth terminal patterns are formed to the earth electrode pattern. The earth terminal patterns of the earth electrode pattern are connected to the earth terminal patterns of the coil electrode patterns. A trimming electrode may be formed for adjusting the passing band frequency of the band-pass filter optionally.