| 摘要 |
PURPOSE: To provide a ladder-type surface acoustic wave filter wherein its desired frequency adjustment can be performed by the one-time deposition of its insulation film, without narrowing its frequency band. CONSTITUTION: When the wavelength of one terminal surface acoustic wave resonator is called Λ , and the line width of a comb-type electrodes is called W, the ladder-type surface acoustic wave filter, the electrode-duty of the one terminal pair surface acoustic wave resonator defined by the formula, electrode duty = 2xW/Λ , is made larger in the parallel-arm resonator than in the series- arm resonator.
|
