| 摘要 |
PURPOSE: A surface acoustic wave filter is provided to reduce a loss of insertion and an attenuation characteristic of an input signal by using the first filter and the second filter. CONSTITUTION: A surface acoustic wave filter includes the first filter portion(40), the second filter portion(50), and a matching portion(60). The first filter reduces a loss of insertion in a filtering process of an external input signal. The second filter is operated together with the first filter. The second filter improves an attenuation characteristic of the input signal. The matching portion is installed between the first filter and the second filter in order to match the impedance of a filtered signal. The first and the second filter decides the loss of insertion and the attenuation characteristic according to an inter-digital transducer. |
