本研究旨在探討 COMSOL Multiphysics 與 ANSYS 平台於單埠薄膜體聲波共振器（Film Bulk Acoustic Resonator, FBAR）模擬上的應用與整合方法，並進一步分析外部電路對元件諧振特性的影響。傳統模擬多侷限於壓電區域之建模與理想終端激勵，難以涵蓋實際操作中外部非壓電區域（如傳輸線、接地結構、封裝空腔）所產生之寄生效應。為克服此限制，本研究提出一套跨平台模擬流程：以 COMSOL 建構壓電主體結構並進行頻域分析，匯出一埠阻抗資料（S1P），再於 ANSYS Circuit 中連接外部傳輸線模型，實現非壓電區參數與匹配行為之聯合模擬。
初步模擬結果顯示，單純使用 COMSOL 與整合 ANSYS Circuit 兩種方式下的阻抗響應存在顯著差異，特別是在諧振頻率與匹配行為方面。基於此觀察，進一步設計三組不同外部電路條件，分別改變基板介電常數與傳輸線長度，以對應外部等效電容與電感之變化，進行更深入之比較與分析。模擬結果顯示，傳輸線參數主要改變了串聯諧振頻率的位置，且電感變化造成之頻率漂移更為顯著；反諧振頻率則相對穩定，顯示其受壓電區主導的特性。Smith 圖與 Q 值響應進一步驗證了模擬準確性與匹配效能。綜合而言，本研究所提出之多平台整合方法不僅提升模擬精度，也有助於未來高頻元件設計中更真實地考慮封裝與電路環境的交互效應。

This study investigates a cross-platform simulation method integrating COMSOL Multiphysics and ANSYS Circuit for modeling single-port Film Bulk Acoustic Resonators (FBARs). Traditional FBAR modeling usually focuses only on the piezoelectric region and uses ideal terminal excitations, which fails to reflect parasitic effects introduced by external structures such as transmission lines and packaging. To address this, COMSOL is used to build the FBAR core structure and extract its impedance response, which is then imported into ANSYS Circuit for circuit-level simulation.
The primary finding shows that the impedance and resonance response of the device differs notably between standalone COMSOL simulation and the COMSOL–ANSYS integration, particularly in resonance frequency and matching performance. Based on this observation, three additional configurations—modifying substrate permittivity and transmission line length—are explored to further study external circuit impacts. Results indicate that external inductance and capacitance mainly influence the series resonance frequency, while the anti-resonance frequency and Q value remain relatively stable.

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