| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an acoustic wave filter utilizing surface acoustic waves, capable of varying frequency characteristics by a simple configuration and suitably coping with temperature changes, and its control method. <P>SOLUTION: In an acoustic wave filter 1, an acoustic wave filter element 7, a temperature measuring element 9 and a heater element 11 are closely attached and formed on a surface of a diaphragm part 5 of a piezoelectric substrate 3. Thus, though the acoustic wave filter 1 has a simple configuration, the temperature of the acoustic wave filter element 7 is changed by the heater element 11 and the frequency characteristics of the acoustic wave filter element 7 are arbitrarily changed in real time. Especially, by controlling the acoustic wave filter element 7 to a desired temperature by heating the acoustic wave filter element 7 with the heater element 11 while measuring the temperature of the acoustic wave filter element 7 with the temperature measuring element 9, the frequency characteristics of the acoustic wave filter element 7 are adjusted to desired characteristics stably regardless of an ambient temperature. <P>COPYRIGHT: (C)2012,JPO&INPIT |
