| 摘要 |
PURPOSE:To reduce the size of an ultrasonic wave transceiver for plural frequencies by using oscillating elements 4 in common to plural resonance frequencies. CONSTITUTION:An integral number, e.g. four oscillation elements 4 which are as many as elements determined on the basis of the ratio of a maximum double tuned frequency and a basic frequency and have quarter-wavelength radiation surface size are connected longitudinally and laterally in parallel. Then, four parallel-connected oscillators 4 are used for the basic frequency and oscillators 4 are used independently for the maximum double tuned frequency. Therefore, the oscillators are used in common to plural oscillation frequencies, the need to provided a transceiver equipped with oscillators for the respective frequencies is eliminated, and the ultrasonic wave transceiver for the plural frequencies is reduced in size, so that side lobes are reduced. |
