共面波導饋入全彼薛夫激發耦合式開槽陣列天線之設計

Abstract

陣列天線會因為每個單一元素天線激發量的不同，而形成不同的輻射場型。本論文研究一個激發量分佈是 Chebyshev分佈，也就是sidelobe level相同的共面波導饋入耦合式開槽陣列天線。 傳統上設計陣列天線，由於需考慮各天線單元間的耦合效應，所以必須由場論計算出各元素天線的電場或磁場，進而求出等效阻抗或導納值。本論文提出一系統化方法，結合現有模擬軟體，不需經由場論計算即可求得等效阻抗值，之後藉由適當的分配各元素天線的阻抗值，我們便可設計激發量分佈為Chebyshev分佈的陣列天線。 在最後為了驗證此一設計方法，實際製作了四元素及六元素的耦合式開槽天線和理論結果相比較。實驗結果證明此一耦合式開槽天線之設計是可行的。

Different radiation patterns will be induced by different excitation distribution in the antenna array. A coplanar waveguide fed coupling slot antenna array with Chebyshev excitation with equal side lobe level is investigated in this thesis. Conventionally, to consider the mutual coupling between each element in an antenna array, we need to calculate the active impedance or admittance by calculating electric field or magnetic field first. This thesis proposes a systematic method combined with commercial software package to derive the active impedance. The major advantage is that it removes the need for calculation by field theory. After the active impedances are obtained, a CPW fed coupling slot antenna array can be designed with proper impedance matching. Finally, a 4-element and 6-element CPW fed coupling slot antenna array with Chebyshev excitation are designed and fabricated to clarify the design method. From the simulated and experimental results, the design of the coupling slot antenna array is proved to be practical.