用于C波段的薄膜体声波谐振器滤波器

A Film Bulk Acoustic Resonator Filter for C Band Application

研制了一种工作于C波段的薄膜体声波谐振器(FBAR)滤波器。首先利用FBAR的一维Mason等效电路模型对谐振器进行设计,然后采用实际制作的谐振器模型构成阶梯型结构FBAR滤波器,利用ADS软件对FBAR滤波器进行电路原理图以及版图设计优化。仿真结果表明,滤波器的中心频率为5.5 GHz,中心插损为1.79 dB,1 dB带宽为115 MHz,5.3 GHz处抑制为40.29 dBc,5.7 GHz处抑制为64.32 dBc。采用空气隙结构实现了C波段FBAR滤波器芯片,并采用陶瓷外壳进行气密封装。测试结果显示,滤波器的中心插损为2.19 dB,1 dB带宽为111 MHz,5.3 GHz处抑制为26.88 dBc,5.7 GHz处抑制为60.96 dBc。对测试结果与仿真结果的差异进行了分析。

A kind of film bulk acoustic resonator(FBAR) filter for C band application was deve-loped. The resonator was designed using one dimensional Mason equivalent circuit model firstly. On the basis of the prepared resonator model, the ladder FBAR filter was established. The circuit schematic and layout of the FBAR filter was designed and optimized by ADS software. The simulation results show that the filter center frequency is 5.5 GHz, the insertion loss at center frequency is 1.79 dB, the 1 dB bandwidth is 115 MHz, and the rejections at 5.3 GHz and 5.7 GHz are 40.29 dBc and 64.32 dBc, respectively. The FBAR filter chip was realized using air-gap structure. The ceramic package was used in order to ensure hermetization. The measured results show that the filter insertion loss at center frequency is 2.19 dB, the 1 dB bandwidth is 111 MHz, and the rejections at 5.3 GHz and 5.7 GHz are 26.88 dBc and 60.96 dBc, respectively. The differences between measured results and simulation results were analyzed.