以10GHz鎖相迴路相移器為基礎的鎖模光纖雷射頻率穩定與時基調整電路

Abstract

隨著現代電子科技與通訊系統的日新月異，我們需要一個能提供特定頻率的穩定振盪器及相位連續可調的相位移器。 因其特殊應用在相陣列天線，無線通訊，光通訊及電光取樣系統，相位連續可調的微波訊號或是由光處理及光電轉換而得到的光時脈訊號已經被廣泛研究。 在本論文中，我們提出以10GHz電子式數位鎖相迴路相移器為基礎的鎖模光纖雷射頻率穩定與時基調整電路來完成諸如相位連續可調，操作容易及擁有極高的相鎖穩定度等優點，並且能克服一般傳統電子式鎖相迴路相移器受限予電子電路頻寬的限制而提高到Ku頻帶。

本論文主要有三大部分組成: 第一部分介紹鎖相迴路的觀念架構以及相移器的基本操作原理。第二部分簡述鎖模光纖雷射及其運作方式。第三部分主要探討整個數位式鎖相迴路相移器的實現及實驗量測結果，包含系統使用的主要積體電路的操作規範以及利用軟體模擬以高頻微波帶的共平面波導管(CPW)作為高頻佈線layout，並應用在主動式鎖模光纖雷射控制驅動電路。

在實際研究量測結果顯示將控制電壓從0到8伏特的變化下，此數位式鎖相迴路相移器之最大相移範圍可達到723度;且其對應的線性響應為90.375度/伏特。而在長時間穩定性測 量下，系統的微擾度方面可小至0.022度。

With the evolution of modern electronic technology and communication system came the need to provide stable oscillation and continuous phase shift at particular frequencies. Continuously tuning the phase of microwave signal or optical clock via optical or optoelectronic technique has been extensively studied since its particular applications in phased-array antennas (PAAs), wireless/fiber communication and electro-optic sampling (EOS) system. In this thesis, we demonstrate a 10GHz electronic type digital phase locked loop with phase shifter (DPLL-PS) based circuitry for frequency stabilization and delay-time tuning of mode-locked fiber lasers. We propose the electronic type DPLL-PS to establish the phase continuous tunable, operation easily and high phase lock stability and especially to improve the drawback of limited bandwidth up to Ku band range. This thesis consists of three main parts: the first introduces the concept of phase locked loop and operation principle of phase shifter. The second part describes briefly the methods of mode-locked fiber lasers. The third part demonstrates the implementation and test results. In our research, the maximum phase deviation is up to 723o under the change in controlling voltage of 8.0 volts, which is completely independent of operating frequency. A linear transferred function of the DPLL-PS with responsivity of 90.375 o/volt was measured. The phase fluctuation of the DPLL-PS can be as small as 0.022o.