[Retracted] Research and Development of Digital Assembly Process System for Ultrasonic Transducers

Table 1

Diffraction efficiencies at different frequencies.

Drive signal frequency/MHz	115	120	130	140	150	160	170	180
Measured wavelength/nm	620.0	602.6	565.6	534.6	508.3	484.8	465	448.5
Theoretical impedance diffraction efficiency	64.84	62.58	54.17	53.69	51.50	31.86	37.24	33.96
(12 − j × 5.5)/%	76.12	74.79	65.51	67.86	67.09	45.13	51.83	40.55