| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that when the realization of broadening a high-frequency monolithic filter at the center frequency of a 400 MHz band is attempted, an electrode area is reduced, a gap g between electrodes is extremely narrow about ten and severalμm, electrostatic coupling occurs between the electrodes, a guaranteed attenuation amount is largely deteriorated, the thickness of an electrode film becomes extremely thin about several hundreds ofÅ, and a terminal impedance becomes considerably larger than a requested termination condition. SOLUTION: First/second electrodes are arranged on one main surface of a crystal substrate apart at a prescribed interval and a third electrode is provided on the other main surface oppositely to the first/second electrodes in order to constitute a high-frequency and wideband MCF in the constitution of the monolithic filter. The monolithic filter is constituted by providing a large number of small spaces to electrode parts, which are close to the outside from the central part of the monolithic filter, of the first, second, and third electrodes. COPYRIGHT: (C)2005,JPO&NCIPI
|
