| 摘要 |
<p>1491250 Surface wave devices NIHON DEMPA KOGYO CO Ltd 30 Dec 1974 [28 Dec 1973] 56006/74 Heading H3U [Also in Division H1] A lithium niobate plate, for use as a piezoelectric substrate in an elastic surface wave device providing a filter or delay line in VHF/UHF bands, is formed as a Y-cut single crystal rotated about the X-axis by an angle lying in the range 125À6 to 130À1 degrees. Where interdigital electrodes of uniform overlap are formed on the surface of the plate, a cutting angle in this range reduces the ratio of spurious component shear waves to the Rayleigh surface waves to at least 40 dB. An angle of cut of 127À86 degrees suppresses spurious components better than 65 dB, Fig. 4. Suppression may also be achieved with devices having non-uniform electrode overlap using the stated angles of cut.</p> |
