SURFACE ACOUSTIC WAVE DEVICE, AND RECEIVER AND COMMUNICATION SYSTEM USING THE DEVICE

摘要

PROBLEM TO BE SOLVED: To obtain an output of a matched filter at a high level efficiently by arranging one input comb-like electrode and two output comb-like electrodes onto a piezoelectric substrate so as to propagate surface acoustic waves in both directions generated from the input IDT effectively. SOLUTION: An input IDT 121 formed on a piezoelectric substrate 102 stimulates an input code string signal being a SAW signal. Electrode finger pairs of output IDTs 131 arranged in matching with a prescribed code string receive the SAW signal. Then the surface acoustic wave device is used for a matched filter by detecting the code string signal coincident with the code string. The SAW signal generated from the input IDT 121 is given at first to the electrode finger pair at the end of receiving the SAW signal in the 1st output IDT 131. Then after a time equivalent to one-chip length of the code string, the code string is fed at first to the electrode finger pair at the end of the input of the 2nd output IDT 132. The signal is sequentially given to the electrode finger pair closer to the input of the 1st output IDT and the 2nd output IDT alternately after the time equivalent to one-chip length of the code string.