近毫米波汽車防撞系統陣列天線之研發

Abstract

摘要 本論文將會完成一組24GHz 8×8的微帶天線陣列做為汽車防撞感測器之前端天線。天線的設計使用平面式結構以避免破壞車身之美觀。在單一天線設計我們採取的是單埠隙孔耦合微帶天線結構，為了增加隙孔耦合效果我們把隙孔設計成H 型。而在饋入電路的設計上使用並列饋入的方式以達成同相位不同電壓。此外，反射板可使天線背面的幅射減低。此陣列預估主波束寬約10度至15度，增益約18dBi，旁波低於-20dB。

Abstract A 24 GHz 8×8 array antenna used as the front-end antenna of a vehicle collision avoidance sensor is to be designed and demonstrated in this thesis. The aperture-coupled microstrip antennas, which possess a planar configuration and can be integrated with the array feeding network, are adopted as array elements to make the whole design compact. To increase the coupling efficiency, the aperture is designed with H shape. The array is expected to possess a main-lobe beamwidth of about 10° to 15°, a gain of 18 dBi, and side-lobe levels lower than -20 dB. To fulfill these requirements, the chebyshev parallel feed approach with various power dividers of different power ratios is used. Finally, a metal reflector is suitably placed behind the array antenna to decrease antenna's back radiation.