以集總電路模型擷取單埠表面聲波共振器結構參數

Determination Structure Parameters of One-port Surface Acoustic Resonators from Lumped Circuit Model

黃姵棻(Pei-Fen Huang)

指導教授 ： 王曙民

義守大學/電機資訊學院/電機工程學系/碩士(2019年)

摘要

隨著行動通訊產業快速發展，IC製程技術與壓電材料上的進步，開啟表面聲波元件應用於射頻頻率之門，其中，階梯結構表面聲波濾波器因具備低插入損失、寬頻、高旁帶抑制能力、低形狀因子等優異特性，特別適合行動電話中之射頻濾波器。然而，如何藉由高頻電路模擬軟體之模擬電路轉換為表面聲波元件結構，係為開發元件時遭遇之關鍵瓶頸。本研究針對上述問題提出以集總元件模型合成階梯結構表面聲波射頻濾波器，利用類神經網路來將高頻模擬軟體所求得之RLC電路與SAW共振器結構間搭起一座橋樑，有效縮短開發時間。首先，由模擬程式建立SAW結構與相對應集總電路之資料庫，以類神經網路訓練學習出其中的規則，驗證訓練成效後，以一LTE TX濾波器為設計規格，使用利用本論文建立之程式，取得各項SAW共振器結構參數，合成階梯結構表面聲波濾波器並驗證之。

關鍵字

表面聲波共振器 ； 階梯結構表面聲波濾波器 ； 類神經網路

並列摘要

Due to the rapid development of the mobile communication industry, the evolution of IC process technology, and the improvement of piezoelectric materials, surface acoustic wave (SAW) devices have been applied in RF frequency range. Ladder-type SAW filter has find its place in mobile phone as RF filter because of its excellent characteristics such as low insertion loss, high side-band rejection and low shape factor. However, for RF engineering, the key bottleneck is how to convert the lumped model into the structure parameters which include the period of the interdigital transducer (IDT), the numbers of pairs of IDT, the aperture of IDT, the metal thickness ratio of electrode and the metallization ratio, of the one-port SAW resonators. In this work, we studied and proposed the approach which builds a bridge between the lumped circuit model and structure parameters of a one-port SAW resonator. The database of the values of the lumped circuit model corresponding to the structure parameters of the one-port SAW resonators was established first. Then, a four-layered neural network was adopted to learn and obtain the relationship between structure parameters and the lumped circuit model of the one-port SAW resonators. After verifying the training results, a six-stage LTE Tx ladder-type SAW filter was developed to demonstrate the proposed approach.

並列關鍵字

SAW resonator ； Ladder-type SAW filter ； Neural network

參考文獻

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