| 摘要 |
PROBLEM TO BE SOLVED: To provide a variable capacitance element in which a drop is suppressed in Q value due to voltage application at a desired frequency, and also, to provide a variable filter or the like in which insertion losses and phase characteristics are reduced. SOLUTION: The variable capacitance element includes a lower electrode layer, an upper electrode layer, and a dielectric layer that is sandwiched from above and below by the lower/upper electrode layers and has a density larger than that of the upper electrode layer. The phase characteristics of an impedance generated by the voltage application to the lower/upper electrode layers have periodic peaks corresponding to a frequency of a signal to be inputted or outputted. The frequency of the signal is located between the peaks adjacent to each other. COPYRIGHT: (C)2008,JPO&INPIT
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