A Fast Hierarchical Cascade Technique Simulation Method for Surface Acoustic Wave Devices

In order to optimize the time-consuming of hierarchical cascade technique (HCT) during finite-length surface acoustic wave (SAW) device simulation, an impro-ved HCT simulation method was proposed. To improve the stability of calculation and accelerate the simulation, the system matrix is preprocessed by combining column scaling and equilibrium pretreatment technology, which can reduce the condition number and meet the single-precision numerical calculation requirement. An improved mirror cascade method was used to decrease the number of basic unit blocks, which can be extended to rotary cascade to reduce the number of cascade operations. A search tree was designed to find the optimal cascade sequence and make the number of cascading operations to be the minimum. The numerical experiments were carried out that the simulation speed of the proposed HCT simulation method for finite-length SAW devices was 30%-80% faster than that of mirror cascade and single-precision HCT method and 2-3 times faster than that of traditional HCT simulation. A Quartz resonator was manufactured to further testify the feasibility of the proposed method. The experimental results showed that the simulated Y11 is close to the measured Y11, while the speed of the proposed HCT method was 2.16 times faster than the traditional HCT. The experimental results verify that the proposed method can accelerate the SAW device simulation process.