| 摘要 |
PURPOSE: A passage frequency variable type surface elastic wave filter is provided to vary a passage frequency. CONSTITUTION: Variable pads(11) are formed between input/output electrodes(12,13) in a parallel and are electrically connected with side electrodes(14,15). The variable pads(11) are formed by a piezoelectric material to vary each interval(X). The side electrodes(14,15) control the interval of the variable pads(11) to vary a passage frequency by feeding a DC. The side electrodes(14,15) are connected with a power supplying source. In feeding an input signal to the input electrode(12), the signal is converted to an electric signal by the output electrode(13) after converting to a surface elastic wave via the variable pads(11). In feeding the DC, a potential is added to the variable pads(11). Thereby, the interval is changed. The passage frequency band is changed by changing a transferring time of the surface elastic wave between variable pads(11). |
