新型三階濾波天線之研究與開發

Abstract

本計畫擬為三年期之計畫，主要目的在於結合天線與濾波器特性，將天線與濾波器一起設計，達 成一新型濾波天線 (filtering antenna) 的設計，其三年之研究規劃詳列如下： 第一年 (2008/8-2009/7) (一) 一階天線等效電路模型之建立：ㄧ階天線模型可分為串聯共振與並聯共振型，針對這二種共振類 型之一階天線，實際模擬其天線架構，涵蓋其寄生效應等等，建立具明確性與可靠性的等效電路 模型。 (二) 具一階天線極點 (pole) 之新型三階濾波天線的設計：利用濾波器之設計方法進行天線的設計。 將以一階天線取代三階濾波器之最後一階，使天線提供濾波器其中之一階模態，產生新型濾波天 線，其同時具有良好的濾波特性與輻射效應，並可使電路縮小化。 第二年 (2009/8-2010/7) (一) 二階天線等效電路模型之建立：提出多種具二階極點之天線，並建立其等效電路模型。 (二) 具二階天線極點(pole) 之新型三階濾波天線的設計：利用濾波器之設計方法進行天線的設計。將 以二階天線取代三階濾波器之最後二階，使天線提供濾波器其中之二階模態，產生新型濾波天線， 其同時具有有良好的濾波特性與輻射效應，且能讓結構更為小型化。 (三) 具一傳輸零點之濾波天設計:設計具傳輸零點之濾波天線，參考一般頻帶凹口(band-notch)之設計 方式，或缺口基板結構(Defected ground structure, DGS)之特性，改變二階天線之本體結構使之具 有傳輸零點，並藉由利用等校電路模型，使具零點之濾波天線有適當之濾波器規格。 第三年 (2010/8-2011/7) (一) 雙頻天線等效模型與雙頻濾波器之電路架構建立：模擬與應用多種雙頻多階之濾波器，並建立其 等效電路模型。 (二) 新型雙頻濾波天線之設計：設計雙頻之濾波器，並以一雙頻天線架構取代濾波器之一部份，使天 線與濾波器同時共振於相同頻段，而濾波器之二個頻段中的模態之一由雙頻天線所提供，產生新 型雙頻濾波天線，其同時具有有良好的濾波特性與輻射效應，並達到電路面積微小化。 (三)多傳輸零點之濾波天線設計:將具二階或多階極點的天線，修改天線結構，參考在饋入端使用多階 的DGS，或改變天線放置或饋入方式，產生額外的串、並聯電容或電感，進而在通帶外產生兩個 以上的傳輸零點，使濾波天線有更佳的通帶外抑制能力。

This project will be completed in three years. The object is integrated antenna and filter and then the novel filtering antenna design can be achieved. The contents of this project are organized as follows: In the first year (2008/8-2009/7) (1) To establish the equivalent-circuits of the single-mode antenna: The model of the single-mode antenna can be divided into series and shunt resonant types. With regard to the two kinds of resonant-type antenna, the proper equivalent circuit models can be established by full wave simulation and circuit simulation tools. (2) To design a third-order filtering antenna with one antenna pole: By using the design rules of the third-order bandpass filter, the third-order filtering antenna can be designed. The last order of the third-order bandpass filter can be replaced by the single-mode antenna. Therefore, the novel filtering antenna can be designed and it can provide filtering and radiating functions, and the circuits can be miniaturized. In the second year (2009/8-2010/7) (1) To establish the equivalent-circuits of the dual-mode antenna: Various dual-mode antennas will be proposed, and the equivalent circuit modesl of these antennas will be established. (2) To design a third-order filtering antenna with two antenna poles: By using the design rules of the third-order bandpass filter, the antenna can be designed. The last two order of the third-order bandpass filter can be replaced by the dual-mode antenna then two of the resonant modes of the filter can be provided by the radiator. Therefore, the novel filtering antenna can be designed and the circuits can be further smaller. Moreover, the novel filtering antenna can filte and radiate well. (3) To design filtering antenna with transmission zero: By modifying the antenna structure, the transmission zero can be inserted into antenna frequency response. In the third year (2010/8-2011/7) (1) To establish the equivalent circuits of the dual-band bandpass filter and the dual band antenna: Various dual-band bandpass filter will be proposed and simulated, and the equivalent circuit models of these filters will be established. Also, the circuit models of various dual band antennas will be established. (2) To design a dual-band third-order filtering antenna: To design a circuit structure of a dual-band bandpass filter, and one part of the filter’s structure will be replace by a dual-band antenna. Some resonant modes will be provided by the dual-band antenna. Therefore, the novel dual-band filtering antenna can be designed, and all the structure can be further smaller. (3) To design the filtering antenna with multiple transmission zeros: To find the methods of modifying the antenna structure, which can provide more than one transmission zeros in antenna frequency response.