低雜訊放大器設計

Abstract

本文提出一套低雜訊放大器之新型匹配設計方法。此種匹配技術將只使用 串聯元件而無並聯元件。根據此特殊之匹配網路技巧，輔以傳統之史密斯 圖及現代微波計算機輔助設計程式所提供之便利功能，將可順暢地完成放 大器之設計工作。吾人利用此套方法設計了五個不同頻段，不同級數，不 同組態之低雜訊放大器原型。並以本實驗室成熟之微波積體電路技術實際 製作。由精密之量測結果顯示，所設計之低雜訊放大器之特性將可由模擬 程式預期。同時，更進一步地利用電磁數值程式精確地模擬元件特性，並 配合漢威公司成熟及控制良好之砷化鎵製程技術，實際製作了四個單晶微 波積體電路，顯示此新型之平面匹配方法將可應用於各領域。 A new design approach for matching a low-noise amplifier (LNA) is presented in this thesis. This novel impedance-matching technique will use series matching elements only without shunt elements. On the basis of this unique technique for matching networks, as well as the aid of the conventional Smith chart manipulation and the convenient facilities available from microwave computer-aided design (CAD) program, the design tasks hence can be accomplished easily and efficiently. Five LNA prototypes with different frequency bands and configurations were designed by using this design approach and fabricated practically by the mature microwave integrated circuit (MIC) technique in our laboratory. As compared with the measured data and simulation results, it was shown that the performances of these LNAs can be predicted. Moreover, we designed four monolithic microwave integrated circuits (MMICs) by using the electromagnetic simulator to accurately simulate their components and fabricated them by the mature and well- controlled GaAs fabrication techniques supported by the Hexawave Inc. It indicates that this new coplanar matching approach can be utilized in every area.