矩形波導尾牆開槽朝有損半空間媒介輻射問題之動差法分析

Abstract

在此我們考慮矩形波導尾牆開槽朝有損半空間輻射的電磁波傳輸問題,此 問題中,藉由動差法(Moment method)推導與求解運算式.尾牆上的特性 ,以兩個孔隙的導納矩陣表示,其中一個表示波導區域,另一個則表示半空 間區域,且這兩個導納矩陣彼此互相獨立,可以分開求解.這問題的解能以 通常的兩個 n-端 (n-port) 網路與電流源並聯連接表示之.而這電流源與 存在尾牆孔隙上的切線磁場相關,且此時孔隙上必須以無窮大導電板隔絕. 藉由這個方法我們可以計算出尾牆上的等效磁流.一但磁流決定,這問題便 以或得解決, 而且這兩個區域的電磁場與一些相關的參數可以藉由各區域 的格林函數 ( Green's function ) 求得. The problem of transmission of electromagnetic waves from a rectangular waveguide into lossy half-space through an end- wall slot is considered. The operator equation is derived and solved via the method of moments. The aperture characteristics are expressed in terms of two aperture admittance matrices, one for waveguide region and one for half-space region.The solution can be represented by two generalized n-port networks connected in parallel with current sources.The current sources are related to the tangential magnetic field which exists over the aperture region when the aperture is closed by an infinite electric conductor. By this method , we can calculate the equivalent magnetic current on the aperture. Once the magnetic current is found , the problem is solved and the fields and the field- related parameters of interest in both regions can be evaluated in a straightforward manner.