2017-08-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/701591摘要：本計畫預計發展一套三維近場微波成像演算法，理論上擁有比文獻中同類型的其他方法更高的解析度、準確度與數值穩定度，適用於單天線成像架構且計算快速。吾人將從天線互易定理與接收天線之等效開路電壓關係式出發，推導出微波成像關係式，利用吾人所提出之相位補償法及輔助方程式加以求解，可有效解決成像解析度與數值穩定性之問題，得到數值上穩定且誤差縮小之矩陣方程式。此外，我們將分析所提出成像演算法之空間解析度及其對於雜訊之抗拒能力，也將提出精確的低通數值濾波器，以便篩選出空間頻域中真正需要求解的方程組之集合，進一步縮短計算時間。由於本計畫所提出之成像演算法可延伸應用至雙天線掃描架構，相關的理論與分析亦將一併探究；據此可討論結合單天線雙極化與雙天線雙極化掃描架構之可行性，並比較其優劣，期能達到更好的成像品質。最後，我們將透過一系列的模擬與實驗結果成像驗證所提出之成像演算法之效能並與其他方法進行比較。<br> Abstract: This project will combine a recently proposed three-dimensional near-field holography and the theory related to the open-circuit voltage. The combined theory will be suitable for a high gain antenna to work for the three-dimensional near-field holography. The three-dimensional near-field holography which we cited is much different from the conventional one which deals with the electromagnetic waves like the acoustic waves and only solves the equations based on the scalar wave problem. Therefore, some electromagnetic interactions with matter are ignored, and it’s also not well-suited for the near-field application. The holography we cited is based on the fundamental equation of the electromagnetic scattering problem. It means that the electromagnetic scattering phenomenon is considered more exactly, and hence the image quality is improved in three-dimensional near-field imaging. Also, it still retains the advantage of holography, i.e., fast and simple. However, this technique still has some disadvantages that are two probes scheme and unsuitable for high gain probe antenna. The motivation for this project is to correct these disadvantages. First, this project will begin with single probe scheme and a high gain probe antenna due to simplification of the system and improvement of the signal to noise ratio. To develop a corresponding theory, we apply the open-circuit voltage of the receiving antenna which could fully describe the characteristic of the antenna. Then we solve the integral equation as the cited paper mentioned and deal with some other accompanied numerical problem. The simulation results in the initial step are great, and further experimental test should be implemented in the future. This project is expected to accomplish the theory of three-dimensional near-field holography for high gain probe antenna and the setup of the measurement system.電磁散射逆散射微波全像術微波成像近場electromagnetic scatteringinverse scatteringmicrowave holographymicrowave imagingnear field