Dielectric-Resonator- Fed Active Horn Antenna

本論文藉由整合號角狀天線（horn antenna）、介電共振器（dielectric resonator）與功率放大器(power amplifier)，成為一可攜式的高指向性天線。在帶狀線與波導的轉接中，藉由介電共振器而增加信號耦合的效率。當此轉接方式用於號角天線時，相對於傳統轉接方式，介電共振器的使用可以提供項對寬的頻寬並改善天線的幅射場型。 藉由天線與功率放大器的結合，可得到更高之天線增益。最後，將兩個號角天線組合於一基板上，經分析與設計後與可得到和(sum)與差模(difference)的天線幅射場型。本架構可以用在衛星通訊、短距離傳輸、微波測試系統及訊號偵測器等；也可做成模組化，以增加系統的擴充性。In this thesis, a high directivity active horn antenna is designed and analyzed, and which is implemented by integrating the horn antenna, dielectric resonator and power amplifier. Using DRs in the stripline-to-waveguide transition, signals can couple to stripline or waveguide efficiently. An 8 \% impedance bandwidth and better radiation patterns in the $E$-plane radiation is observed. By integrating power amplifiers into the horn antenna, antenna gain is increased by 7.1 dB without increasing the circuit volume. Chokes are used to reduce the backward radiation. Finally, dual horn antennas are designed and implemented. Sum and difference patterns are also observed as expected. The invention can be applied in many fields such as satellite communication, short term communication, microwave detection system, and signal detector, etc. They can be moduled for extensive application.Abstract Table of Contents ii List of Figures vii 1 Introduction 1 2 Active H-plane Horn Antennas . . . . . . . . . . . . . . . . . . . .16 2.1 Waveguide-Fed Horn Antennas . . . . . . . . . . . . . . . . . . . . . . 16 2.2 Dielectric Resonator . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . 19 2.3 Power Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . 22 2.4 Class-A Power Amplifier Design . . . . . . . . . . . . . . . . . . . . . 29 3 DR-Enhanced Waveguide-Fed H-plane Horn Antenna 35 3.1 Antenna Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 3.2 Simulations and Measurements . . . . . . . . . . . . . . . . . . . . . . 37 3.3 DR-Enhanced Horn Antenna with Power Amplifier . . . . . . . 40 3.4 Reduction of Back-Radiation . . . . . . . . . . . . . . . . . . . . . 41 4 Dual Horn Antennas 47 4.1 Sum and Difference Patterns . . . . . . . . . . . . . . . . . .. . . . 47 4.2 Antenna Element . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5