Piezoelectric devices for frequency control and selection in Japan

Typical results of the distribution of SAW velocity in a substrate as measured by the line-focus-beam ultrasonic microscope are reported. The designs of oscillator circuits using bulk wave and surface acoustic wave resonators are analyzed. Maximum input power for SAW devices is limited by electrode migration, which depends on the maximum stress at interdigital-transducer electrodes. Stress distribution in a SAW substrate can be calculated and shown graphically by the finite element method. The use of oriented Al electrodes, instead of ordinary amorphous Al electrodes, can increase the life of quartz-crystal SAW resonators over 1000 times. Finally, the reliability of dipped resin packages for TV VIF SAW filters is reported.<
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