本論文提出利用不規則形狀反射板之寬頻圓極化孔徑天線設計。天線由L形結構饋入矩形孔徑和L形寄生元件所組合而成，藉由L形饋入結構，從而產生圓極化。L形饋入結構加入矩形金屬與殘段，從而拓寬阻抗頻寬；使用L形寄生元件與擾動結構，產生五個圓極化模態，從而拓寬軸比頻寬。最後在孔徑天線下方加入反射板，用以提高天線增益，除此之外，不規則形狀能降低天線剖面厚度。本論文設計於Ka頻段(26.50-40.00 GHz)。 論文中天線的設計使用台灣半導體研究中心RO4003板製程製作，天線厚度為0.125λ0(λ0為26.5GHz的自由空間波長)。量測結果顯示|S11|頻寬36.13%(27.76 GHz-40.00 GHz)，3-dB軸比頻寬18.20%(26.71 GHz-32.06 GHz)和4.43%(34.61 GHz-36.18 GHz)，天線峰值增益7.97 dBi，所提出之天線在各個模態中皆為右手圓極化輻射。 ;The thesis proposes the broadband circularly polarized aperture antenna using a reflector of irregular shape. The antenna is composed of L-shaped structure feeding a rectangular aperture and L-shaped parasitic element. Circular polarization is achieved due to the L-shaped feeding structure. Also, adding rectangular metal and stubs to the feeding structure can enhance the impedance bandwidth. By using the L-shaped parasitic element and perturbative structure can produce five circular polarization modes, thereby enhancing the axial-ratio bandwidth. Finally, a reflector is added under the aperture antenna to increase the antenna gain. In addition, the irregular shape of the reflector can reduce the thickness of the antenna profile. The proposed design accommodates the frequency band 26.5 GHz-40.0 GHz of Ka band. The proposed designs in the thesis use the RO4003 board process from Taiwan Semiconductor Research Institute, and the antenna thickness is 0.125λ0 (λ0 is the free space wavelength of 26.5 GHz). The measured results show that |S11| bandwidth is 36.13% (27.76 GHz-40.00GHz), the 3-dB axial ratio bandwidths are 18.20% (26.71 GHz-32.06 GHz) and 4.43%( 34.61 GHz-36.18 GHz), and the peak gain is 7.97 dBic. The proposed antenna is right-handed circularly polarized in all modes.
