APPARATUS FOR MEASURING PROPAGATING SPEED OF SURFACE WAVE ON SURFACE ACOUSTIC WAVE SUBSTRATE

摘要

PURPOSE:To make it possible to use the apparatus in actual mass-production shops, by applying the outputs having a time interval and a frequency interval to a measuring substrate, which is provided on a mutual conversion coupler for an electric signal and a surface acoustic wave signal, and computing a propagating speed based on phase difference and frequency data. CONSTITUTION:A sample to be measured 10 made of a single crystal of LiNbO3 is sucked to a mutual conversion coupler 25, in which a single crystal plate 4 having the same material and output electrodes 1 and 2 is contained in a vacuum-sucking holding container 11 made of metal. Outputs having a time interval DELTAt and a frequency interval DELTAf from a frequency oscillator 26 are inputted to the coupler 25 and measured by a frequency counter 28. The results are stored in a frequency array memory 30. The phase defference between the output and the input of the coupler 25 is measured by a phase difference measuring device 27 and stored in a correcting phase difference array memory 32 through a phase difference array memory 29 and a phase difference correcting device 31. Based on the data of both memories 30 and 32, the surface-wave propagating speed is computed by an operating means 33.