A SAW filter using bulk wave

摘要

PURPOSE: A surface acoustic wave filter using a bulk wave is provided to enhance characteristics of the surface acoustic wave filter by forming IDTs(Inter-Digital Transducer) on an upper face and a rear face of the surface acoustic wave filter. CONSTITUTION: A piezoelectric substrate(10) is formed by a piezoelectric material. The piezoelectric substrate(10) generates a surface acoustic wave filter. A plurality of IDT portions(11a,11b) is used for converting an electric signal and a surface acoustic wave. A plurality of signal transmitting portion(12a,12b) is located between the IDT portions(11a,11b) in order to transmit signals. The IDT portions(11a,11b) are formed with an input IDT portion(11a) for converting an input signal to the surface acoustic wave and an output IDT portion(11b) for converting the surface acoustic wave to an electric signal. The transmitting portions(12a,12b) is formed with the first transmitting portion(12a) and the second transmitting portion(12b).