PURPOSE: To prevent deterioration in the attenuation characteristic by forming a recessed part to a location of a ground electrode opposed to a resonance electrode, making the gap between the tip face of the resonance electrode and the resonance electrode opposed part of the ground electrode wide and making the gap between the resonance electrode adjacent to the tip face and the ground connection part narrow.
CONSTITUTION: In an interdigital filter 1, a recessed part 5 is formed to a part of the ground electrodes 3a, 3b opposed to the resonance electrode 4 to make the gap S3 between the tip face of the resonance electrode 4 and the resonance electrode opposed part of arm electrodes 3a, 3b wide. Simultaneously, the gap S4 between the tip face and the ground electrode connection part of the adjacent resonance electrode 4 is made narrow. Thus, since the coupling capacitor with skipped by one stage is decreased, the deterioration in the attenuation characteristic is avoided.
HATTORI JUN
KATO HIDEYUKI
| JP61166603B |
| US4266206A | 1981-05-05 |
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