| 摘要 |
PURPOSE: To make it possible to regulate the frequency within a specified range by a method wherein a capacitor which is one constituent of a parallel resonator is divided into a plurality of capacitor elements and the frequency is regulated by trimming a capacitor electrode, one of the divided capacitor elements. CONSTITUTION: At the bottom in the thickness direction of a band pass filter, a protective layer 1 is formed. On the protective layer 1, a dielectric layer 3, a print coil 4, another dielectric layer 5, a capacitor forming layer 7, a capacitor forming layer for regulating input and output impedances 9, a capacitor forming layer 11 for a resonance circuit, a capacitor forming layer for regulating a frequency 13, second capacitor electrode layers for 2 resonance circuit 14a, 14b, and a protective layer 15 are formed in this order. Trimming of this filter is performed by trimming the second capacitor electrode layers 14a, 14b together with the protective layer 15 in the upper layer. By this method, the frequency can be regulated within a specified range even if the whole part of the electrodes is removed by trimming. |
