SURFACE ACOUSTIC WAVE FILTER OF DUAL BAND/DUAL MODE SYSTEM

摘要

PURPOSE: A surface acoustic wave filter of a dual band/dual mode system is provided to form a communication system using different frequency bandwidths by using one surface acoustic wave filter. CONSTITUTION: The first input IDT(Inter-Digital Transducer)(16) converts an external electric signal to a mechanical signal in order to pass the first frequency band. The first output IDT(18) converts a filtered mechanical signal to the electric signal. The first ground bar(20) is formed between the first input IDT(16) and the first output IDT. The first SAW(Surface Acoustic Wave) filter portion performs a filtering process to pass the first frequency band. The second input IDT converts the external electric signal to the mechanical signal in order to pass the second frequency band. The second output IDT converts the filtered mechanical signal to the electric signal. The second ground bar is formed between the second input IDT and the second output IDT. The second SAW filter portion performs the filtering process to pass the second frequency band.