| 摘要 |
PURPOSE:To measure a specific position of a sample only in a specific detection area without reference to frequency by varying an F number with frequency effectively and fixing azimuth resolution. CONSTITUTION:A lower electrode 205 is vapor-deposited on one end surface of a lens material 200 and a piezoelectric thin film 220 is vapor-deposited thereupon. Further, two upper concentric electrodes 230 and 210 are provided thereupon and terminals 240 and 250 are provided to them respectively. Two terminals 250 and 240 of a sensor 300 which transmits and receives the ultrasonic convergent beam of an ultrasonic microscope are coupled with an ultrasonic wave transmitter receiver 320 through RF analog switches 310a and 310b. When the carrier frequency of the oscillator 320 is 330MHz, the upper electrodes 210 and 230 are driven with the switches 310a and 310b on, realizing F=0.7. Further, when the carrier frequency of the oscillator 320 is 600MHz, only the upper electrode 230 is driven with only the switch 310 on, realizing F=1.4. |
