S波段网格型FBAR滤波器的研制

Research and Fabrication of the Lattice-Type FBAR Filter for S Band

介绍了一种单端口,端口阻抗为50Ω的S波段宽带薄膜体声波谐振器（FBAR）滤波器,该滤波器采用网格型结构的FBAR滤波器芯片级联巴伦芯片实现。对宽带FBAR滤波器芯片的设计过程、工艺实现过程进行了说明。采用0.35μm Ga As工艺实现了3~8 GHz频率范围的巴伦芯片,在FBAR滤波器芯片的中心频率处,幅度不平衡度为0.53 d B,相位不平衡度为0.55°。制备的FBAR滤波器通带频率范围为3 100~3 400 MHz,1 d B带宽约为369 MHz,在2 660 MHz和3 840 MHz处带外抑制分别为45.6 d Bc和41.3 d Bc,尺寸仅为12 mm×7 mm×2.9 mm。将实测结果与仿真结果进行了对比,两者一致性很好。

A kind of wideband film bulk acoustic resonator（ FBAR） filter for S band was introduced,which has only one input port and one output port,and the ports impedance are both 50 Ω. The filter was realized by the cascading lattice-type FBAR filter chip and Balun chips. The design and technics process were illustrated for the wideband FBAR filter chip. Balun chip was realized by 0. 35 μm Ga As technology with the frequency range of 3- 8 GHz,the amplitude unbalance and phase unbalance are 0. 53 d B and 0. 55° respectively at the center frequency of the FBAR filter chip. The frequency range of the FBAR filter is from 3 100 MHz to 3 400 MHz,the 1d B bandwidth is 369 MHz,the stopband rejection at 2 660 MHz and 3 840 MHz are 45. 6 d Bc and 41. 3 d Bc respectively,the size of the FBAR filter is only 12 mm × 7 mm × 2. 9 mm. Comparing the measured results and simulation results,the consistency is very good.