单向单相分布式声反射结构的声表面波滤波器

Single Phase Unidirectional DART Structure SAW Filter

分析了均匀分布式声反射(DART)和抽指DART换能器的结构,并用准静态分析法和反射列阵模型(REM)推导出它们的P矩阵、Y矩阵及S12参数。设计了一个中心频率为140 MHz,相对带宽为0.1%,插入损耗10 dB,波纹小于1 dB,带外大于40 dB的窄带低损耗滤波器。压电基片材料为水晶,器件封装尺寸为13 mm×6.5 mm的表贴外壳。

This paper describes of uniform DART（Distributed Acoustic Reflection Transducer） structure and withdrawal weighted DART structure was analyzed. P-matrix,Y-matrix and S12 parameter by quasi-static formulate and REM（Reflective Array Model） was achieved. SAW filter with 140 MHz center frequency and a fractional bandwidth of 0.1 percent was designed and fabricated on a ST-X quartz substrate. An insertion loss of 10 dB and passband ripple of 1 dB and stop-band attenuation of 40 dB or more were achieved. Device package size was 13 mm × 6.5 mm in SMD.