毫米波360°連續可調式相移器及其於波束掃描反射式陣列天線之應用

Abstract

本論文提出一個適用於毫米波頻段的波束掃描反射式陣列天線之架構，具備高增益、窄波束、波束掃描等特性。此外，為達成反射式陣列天線之波束掃描功能，本論文亦設計一反射式類比相移器，具有360度連續可調之相位變化，並且具有結構簡單、製作容易及成本低廉的優點。除了完成上述天線及相移器設計，本論文也會分析相移器應用於反射式陣列天線之波束掃描情形。 首先，介紹現有文獻用來設計具有波束掃描功能的反射式陣列天線之天線輻射單元及其架構所使用的相移器；而這正是反射式陣列天線是否具有波束掃描功能之關鍵。接著，介紹相移器原理與各種不同設計的相移器，並從中選擇適合本論文使用的天線架構的相移器，完成其在毫米波頻段的設計與量測。第三部分是完成反射式陣列天線的反射面設計，並搭配前述所設計的相移器構成具有波束掃描功能的反射面。最後，探討反射式陣列天線之輻射電磁場組成，將其分成「散射電磁場」與「再輻射電磁場」，並以此方式驗證波束掃描之功能。

This thesis proposes an architecture of beam steering reflectarray antenna at millimeter wave bands, which has the properties of high-gain, narrow beamwidth, beam steering, etc. Besides, in order to achieve the beam steering function of the reflectarray antenna, this thesis also designs a reflective-type analog phase shifter with phase tuning range of more than 360°. It has the advantages of simple structure, easy manufacture and low cost. In addition to completing the design of reflectarray antenna and phase shifter mentioned above, this thesis also analyzes the beam steering function of the beam steering reflectarray antenna. In the first chapter, the radiating elements and the associated phase shifters, which are used to design beam steering reflectarray antenna by some existing literature, have been introduced. This is the critical factor whether the reflectarray antenna has the function of beam steering. The fundamental of phase shifter and different types phase shifter are introduced in chapter two. In chapter three, we choose the phase shifter which is suitable for the antenna architecture used in this thesis and complete its design and measurement in the millimeter-wave bands. Chapter four completes the design of the reflecting surface of the reflectarray antenna and combine it with the phase shifter designed in chapter three to form a reflecting surface with the function of beam steering. In the last chapter, the composition of the radiating electromagnetic field of the reflectarray antenna will be discussed in terms of “scattering field” and “re-radiated field”, which were used to verify the function of beam steering.