應用於超寬頻之低雜訊放大器

Abstract

本論文提出適合用於超寬頻的低雜訊放大器。在元件的選擇上，使用由GCTC所提供的異質接面雙載子電晶體( heterojunction bipolar transistor, HBT )。電路架構上，則採用達靈頓回授式放大器結構。除了基本架構外，本論文另外提出三種衍生架構： (1)為節省功率損耗，利用一個基極和集極相接的電晶體取代基本架構中提供偏壓的電阻。 (2)為改善雜訊指數，在輸出級並聯數個電晶體。 (3)為提高增益，直接串接兩個基本架構。 除了理論分析和模擬結果，實際製作出來的電路和量測結果呈現在最後一個章節中。

Low noise amplifiers for ultra-wideband application are presented in this thesis. Darlington feedback topology has been adopted to design a broadband amplifier and demonstrated using heterojunction bipolar transistors (HBT). Except for the basic Darlington feedback topology, three other derivative configurations are introduced in this thesis: (1) To save the power consumption, a transistor, whose base and collector are connected together, is utilized to substitute the bias resistor. (2) To improve the noise figure, parallel several transistors at the output stage. (3) To get higher insertion gain, cascade two basic configurations. In addition to theoretical analyses and simulation results, the circuits and measurement results are presented in the last chapter.