图1 基于L型结构的FBAR滤波器的工作原理

Fig. 1 Operating principle of the L-type FBAR filter (a) Electrical characteristics of the idealized FBAR; (b) Fundamental unit of the L-type structure; (c) Transmission response

图2 FBAR与压电薄膜的等效电路模型

Fig. 2 FBAR and the equivalent circuit model of piezoelectric thin film (a) Schematic structure of FBAR; (b) Mason equivalent circuit model of the piezoelectric thin film

图3 双工器的非线性失真[23]

Fig. 3 Nonlinear distortion of the duplexer[23] (a) Circuit diagram; (b) Signal distribution

图4 基于AlN薄膜的BAW谐振器[25]

Fig. 4 BAW resonator based on AlN thin film[25] (a) Nonlinear circuit model; (b) Second harmonic response; (c) Third harmonic response

图5 具有边缘布拉格反射层结构的谐振器[31]

Fig. 5 Resonator with edge Bragg reflection layer structure[31]

图6 FBAR的(a)横截面和(b)俯视图[35]

Fig. 6 (a) Cross-section and (b) top view of FBAR[35]

图7 BAW谐振器离散化模型及电极馈电引线[36]

Fig. 7 Discretized model and electrode feed lines of BAW resonator[36] (a) Schematic representation of discretized resonator model; (b) Two resonators in series and connected by broad lead; (c) Single resonator connected by narrow lead

图8 基于单晶和多晶AlN的3.55 GHz FBAR滤波器[54]

Fig. 8 3.55 GHz FBAR filter based on single-crystal and polycrystalline AlN[54] (a) Measured power sweep at right band edge of the filters; (b) Measured insertion loss of the filters versus input power

图9 单晶AlN-FBAR滤波器[55]

Fig. 9 Single crystal AlN-FBAR filter[55] (a) Actual layout; (b) Simulated and measured transmission response curves

图10 FBAR滤波器传输响应的测量值[64]

Fig. 10 Measured values of transmission response of FBAR filter[64]

图11 基于Al0.8Sc0.2N薄膜制备的FBAR滤波器的实验结果[65]

Fig. 11 Experimental results of FBAR filter fabricated with Al0.8Sc0.2N film[65] (a) Transmission response of FBAR filter; (b) Return loss of the FBAR filter

图12 Sc掺杂量对Al1−xScxN薄膜质量及表面形貌的影响[69]

Fig. 12 Effect of Sc-dopant concentration on crystal quality and surface morphology of Al1−xScxN thin films[69] (a-c) TEM dark-field images and electron diffraction patterns for 10%, 31%, and 42% Sc content; (d-f) Corresponding SEM plane views

图13 两步法(Sample 1)和单步PVD工艺(Sample 2)所获FBAR的性能对比[86]

Fig. 13 Performance comparison of FBAR obtained by two-step (Sample 1) and single PVD (Sample 2) processes[86] (a) Frequency impedance characteristic curves; (b) Smith chart

图14 SABAR工艺示意图[87]

Fig. 14 Schematic diagram for SABAR process[87] (a) Combination of PLD and MOCVD AlN film; (b) Bottom electrode and bonding layer sputtered on top of AlN layer; (c) Resonator structure

图15 结合FBAR与IPD技术的N77频段混合滤波器[88]

Fig. 15 N77-band hybrid filter based on FBAR and IPD technology[88] (a) Design schematic; (b) Simulated transmission response curve

图16 基于FBAR与IPD技术的N41频段混合滤波器[89]

Fig. 16 N41-band hybrid filter based on FBAR and IPD technology[89]

图17 用于滤波器参数预测的卷积混合网络[94]

Fig. 17 Convolutional hybrid network for the filter parameter prediction[94]

图18 LTE 4G/5G射频前端模块结构[98]

Fig. 18 LTE 4G/5G radio frequency front end module structure[98]