單晶微波低雜訊放大器設計

Abstract

本文提出一套低雜訊放大器之系統化設計方法.此套方法乃是根據元件 之特性,利用史密斯圖操作方式,得到適當的匹配網路及元件值.同時利用 現代化計算機輔助設計所提供之便利功能,將可簡化設計過程及迅速完成 工作. 吾人利用此套方法,配合漢威公司提功之1um砷化鎵今半接面場效 電晶體製程之元件庫模型,設計一適用於1.9GHz之二級低雜訊放大器原型. 經由程式模擬,工作於1.9GHz期小訊號增益和雜訊表現分別為15.4dB和2.3 dB.在5伏特之工作電壓下,總消耗電流為60毫安培.此電路目前正由漢威工 司製程之中. A system design approach for designing a multi-stage low noise amplifier is presented. It is based on the conventional Smith chart manipulation and the unique termination technique for matching networks. And it takesadvantages of the facilities available from microwave computer-aided design(CAD) programs, the design tasks hence can be accomplished easily and efficiently. By using this design approach, the peototype of a 1.9 GHz two-stage amplifier(LNA) was designed. We simulate the circuit with models of the cell library provided by Hexawave Inc. . The results for the 1.9 GHz amplifier show a small-signal gain of 15.4dB and Noise Figure of 2.3dB with a 5V power supply while drawing 60mA current. The LNA is now being fabricated by Hexawave Inc. .