In general, a medical ultrasonic transducer is composed of piezoelectric layer, matching layer, and backing layer. Among them, the backing layer can shorten the duration of the ultrasonic pulse by attenuating the vibration of the piezoelectric layer resulting in increased axial resolution [1,2]. The thickness of the backing layer is typically very thick and heavy for enough attenuation effect. Therefore, reducing thickness of the backing layer can contribute to decrease overall weight of the transducer. Small-sized transducers such as intravascular ultrasound (IVUS) transducer would require the thin backing layer, especially. However, the thin backing layer can be suffered from insufficient attenuation effect and the unwanted reflected signal comes from the bottom of the thin backing.
In order to solve this problem, in this study, we investigated a structure of backing layer and proposed the novel structure of the backing layer capable of suppressing the generation of...