| 摘要 |
PURPOSE:To realize delay lines for transmission and reception on one piezoelectric substrate, by providing reflective gratings, which reflect surface acoustic waves at right angles, and reed-screen type electrodes for input and output on the piezoelectric substrate. CONSTITUTION:The first reflective grating 12, the second reflective grating 13, and the third reflective grating 14 which reflect surface acoustic waves in the direction perpendicular to the propagation direction are arranged successively in parallel on a piezoelectric substrate 11. Reed-screen type electrodes 15, 16, 17, and 18 for input and output conversion are provided to the left of the reflective grating 12, both sides of the reflective grating 13, and the right of the reflective grating 14 respectively Surface waves radiated from the reed-screen type electrode 16 are reflected by reflective gratings 13 and 12 and reach the reed- screen type electrode 16, thus obtaining a down chirp delay line; and surface waves radiated from the reed-screen type electrode 17 are reflected by reflective gratings 13 and 14 and reach the reed-screen type electrode 18, thus obtaining an up chirp delay line. |
