波束可掃描之波導漏波天線設計－理論分析與天線製作量測

Abstract

本論文旨在以理論分析、軟體模擬、天線製作及實驗量測，來探討波束可掃描之波導漏波天線的可行性。 為使天線具有波束掃瞄的能力，於槽孔導波管內的縱向軸上，置放一介電板，因槽孔導波管的橫向電場屬不均勻分布，變化該介電板置放在槽孔導波管內橫軸向的位置，對槽孔導波管內的電磁場產生不等量的干擾，因此改變漏波之縱向傳波常數，以改變漏波波束之主輻射角，令天線具有波束掃瞄之能力。在理論分析部分，使用“縱向諧振方程”，推導色散關係式，以計算波導傳波常數的相位常數及耗損常數。 本論文中之理論分析、軟體模擬及實驗量測所得之天線場型分布及波束之主輻射角等數據，都很接近，證明本波束可掃瞄天線之設計，確為可行。在Ku波段操作，天線波束掃描之範圍，可達23度。

In this dissertation, we presented a beam adjustable antenna made up of a slitted waveguide and a dielectric slab. In order to steer the radiation main-beam angle, we changed the phase constant of the waveguide mode by inserting a dielectric slab to perturb its field distribution. The direction of radiation main-beam can be steered by dynamically changing the position of the dielectric slab. In the theoretical analysis, the dispersion relation including the phase and attenuation constants, were determined by solving the transverse resonance equation. An agreement between the theoretical and experimental radiation pattern verifies the beam-steering mechanism. Up to 23o beam-steering angle can be achieved using this approach.