Instability Analysis of a Microwave Voltage-Controlled Oscillator

本論文分別由阻抗、導納、反射係數、穩定因子及正規行列式函數(normalized determinant function, NDF)分別討論振盪器之不穩定性線性分析方法。 通常分析振盪器不穩定性是採用阻抗、導納、反射係數、穩定因子K-Δ及μ，但其前提是羅列特(Rollet)條件須成立。所以回歸到電路的網路行列式(network determinant)，由正規行列式函數分析振盪器的不穩定性。 有關壓控振盪器設計，首先討論電晶體及回授組態，然後分別使用不同之線性方法分析其不穩定性，並輔以模擬說明，雖然量測結果與模擬之振盪頻率不吻合，但接近模擬顯示之可能振盪頻率。This thesis presents the instability analyses using various linear methods including impedance, admittance, reflection coefficient, stability factor, and normalized determinant function (NDF). Instability of oscillator is usually analyzed with impedance, admittance, reflection coefficient, stability factor K-Δ and μ, but the Rollet proviso should be satisfied. Therefore, the use of circuit network determinant to analyze the oscillator instability through NDF is applicable. On the voltage controlled oscillator design, we firstly investigate the various configurations of transistor and its feedback network. Various linear methods are then applied to perform the instability analysis with the help of MWO microwave software. Although the measurement result of oscillation frequency is not consistent to that of the simulation result, it is close to the possible oscillation frequency shown in the simulation.誌謝…………………………………………………………………i 中文摘要………………………………………………………………ii 英文摘要………………………………………………………………iii 目錄…………………………………………………………………….iv 第一章 不穩定性線性分析方法………………………………………1 1.1 振盪器原理…………………………………………………1 1.2起振條件…………………………………………………………2 1.2.1阻抗………………………………………………………3 1.2.2導納………………………………………………………3 1.2.3反射係數…………………………………………………5 1.3散射參數 與穩定因子K-Δ及μ………………………………5 1.4奈奎斯特準則……………………………………………………7 1.5正規行列式函數…………………………………………………9 第二章 微波壓控振盪器設計與模擬分析……………………………11 2.1電晶體組態與回授網路選擇…………………………………11 2.1.1共源極組態及模擬分析…………………………………11 2.1.2共閘極組態及模擬分析…………………………………20 2.2起振條件分析…………………………………………………29 2.3正規行列式函數分析…………………………………………31 2.4匹配網路選擇…………………………………………………33 第三章 電路製作與驗證………………………………………………36 3.1電晶體組態及回授網路製作驗證……………………………36 3.2壓控振盪器特性量測驗證……………………………………38 第四章 結論……………………………………………………………40 參考文獻……………………………………………………….……….4