In this study, a phase-cancelled backing layer for ultrasound linear array transducer is presented. The proposed backing layer is composed of multiple blocks operated by phase inversion technique. Inside of the proposed backing layer, the phase of the reflected signal can be cancelled by adjusting acoustic impedance, piezoelectric layer contact area, and thickness of each block constituting the backing layer. Therefore, the total thickness of the backing layer can be significantly reduced while maintaining the performance. Using finite element analysis (FEA) simulation, its performance was verified based on the 8 MHz linear array transducer. Two types of bulk-type backing layers with different thickness were also simulated to compare the performance of the proposed method. In the case of narrow bandwidth signal without the matching layers, the 10 mm-thick bulk-type backing layer yielded a -6 dB bandwidth of 37.2%. When its thickness was reduced to 2 mm, the -6 dB bandwidth was decreased to 17.3% due to the reflected back-wall signals. However, the -6 dB bandwidth of the proposed backing layer with 2 mm thickness was 39.5%, which is similar to the thick bulk-type backing layer. In the case of broad bandwidth signal with the matching layers, the proposed transducer also exhibits similar performance compared with the thick bulk-type backing layer. The narrow bandwidth signal was experimentally demonstrated by using a prototype array transducer with the proposed technique, and the performance was similar to the simulation. Thus, the proposed method can reduce the thickness of the backing layer of the various array transducers.

中文翻译：

---

超声线性阵列换能器的相消衬层：建模和实验验证。

在这项研究中，提出了一种用于超声线性阵列换能器的相消衬层。所提出的背衬层由通过相转化技术操作的多个块组成。在建议的衬里层内部，可以通过调节声阻抗，压电层接触面积和构成衬里层的每个块的厚度来抵消反射信号的相位。因此，可以在保持性能的同时显着减小背衬层的总厚​​度。使用有限元分析（FEA）仿真，基于8 MHz线性阵列换能器验证了其性能。还模拟了两种具有不同厚度的块状背衬层，以比较该方法的性能。在窄带宽信号没有匹配层的情况下，10毫米厚的块状衬层的-6 dB带宽为37.2％。当其厚度减小到2 mm时，由于反射的后壁信号，-6 dB带宽减小到17.3％。但是，建议的厚度为2 mm的衬层的-6 dB带宽为39.5％，与厚的块状衬层相似。在具有匹配层的宽带宽信号的情况下，与厚体型衬层相比，拟议的换能器也表现出相似的性能。通过使用提出的技术的原型阵列换能器，实验证明了窄带宽信号，其性能类似于仿真。因此，所提出的方法可以减小各种阵列换能器的背衬层的厚度。