基于多条耦合器声表面波器件的小波重构

提出了一种基于多条耦合器声表面波器件实现小波重构的新方案．利用基于多条耦合器声表面波器件的传递函数等于输入与输出加权换能器传递函数之积的关系，对输入、输出叉指换能器分别进行小波和重构小波加权，在单块器件上实现了小波重构功能，避免了二次插入损耗的产生．利用多条耦合器和双声路对称结构，将沿晶体表面传播的体声波进行了分离和消除，抑制了三次渡越信号，降低了接收损耗，使器件的响应特性得到了改善．实验结果表明，用新方案实现的小波重构器件比用早期方案实现的小波重构器件在插入损耗、体声波抑制、通带波纹和接收损耗方面均有明显的改善．

Wavelet Reconstruction Using Surface Acoustic Wave Device Based on Multistrip Coupler

A novel scheme of wavelet reconstruction using surface acoustic wave(SAW) device based on multistrip coupler(MSC) is proposed.The scheme is established under the condition that the transfer function of SAW device based on MSC is the product of the transfer function of input weighted interdigital transducer(IDT) and that of output weighted IDT.Simultaneously, input IDT and output IDT are weighted with wavelet function and reconstruction wavelet function,respectively.Wavelet reconstruction function is realized in one SAW device,which avoids second insertion loss.Furthermore,MSC and dual track symmetric structure can separate and eliminate bulk acoustic wave(BAW) propagating along crystal surface,suppress triple transit signal and decrease the receiving loss,which improves the response performance of device.The experimental results confirm that the insertion loss,BAW suppression,passband ripples and receiving loss of the wavelet reconstruction device using the new scheme are remarkably improved using early schemes.