| 摘要 |
PURPOSE:To set the band characteristic of two channels with one chip by giving a shift being an optional multiple of a wavelength decided by the sound velocity and the filter center frequency to the center in the crossing broadwise direction of a couple of comb-line electrodes. CONSTITUTION:A weighted comb-line electrode 2 and a normal form electrode 4 shifted by 1/8 wavelength at the center A in the crossing broadwise direction to the normal form electrode crossed straightly are provided on the plane of a piezoelectric substance 1. As a result, only an attenuation electrode is shifted without remarkable design change and a two-channel band characteristic is obtained by one filter. |
