應用分散式架構設計之寬頻放大器

Design of Broadband Amplifiers Using Distributed Configurations

巫新淦(Shin-Gann Wu)

指導教授 ： 黃天偉

國立臺灣大學/電機資訊學院/電機工程學研究所/碩士(2007年)

https://doi.org/10.6342/NTU.2007.10577

摘要

在寬頻系統中，如光纖通訊、超寬頻射頻通訊及無線電天文望遠鏡，由於傳輸速度相當快、資料頻寬大，需要低成本、平坦的頻率響應及高頻之電路。此類電路已是目前的研究重點。本論文主要包括微波分散式放大器之設計及實現。
本論文的目的在於利用分散式架構設計寬頻之放大器。文中回顧了放大器的基本操作原理及基礎定律，並且討論到雜訊和輸出功率。然後再針對兩種寬頻放大器架構討論之：一種為傳統分散式放大器(CDA)，另一種為串接單級分散式放大器(CSSDA)。
本論文共提出四個電路，皆是使用已封裝之離散電晶體，製作於FR4 印刷電路板上：
第一個為2.4GHz單級放大器，這是一個基本且架構簡單的入門放大器，製作於厚度0.6mm的FR4 印刷電路板上，偏壓在VCE=3V、IC=10mA時，於2.4GHz量得增益為6.6dB，輸入及輸出反射損耗分別為31.4dB及30.1dB，隔離度為16dB。
第二個為兩級寬頻放大器，製作於厚度1.6mm的FR4 印刷電路板上，偏壓在VDS=4V、IDS=43.1mA時，於0.5~3GHz量得增益為10.1±1.4dB，輸入及輸出反射損耗分別大於9.1dB及12.4dB，隔離度大於20dB。
第三個為四級寬頻放大器，製作於厚度1.6mm的FR4 印刷電路板上，偏壓在VDS=4V、IDS=94.8mA時，於0.5~3GHz量得增益為15.1±1.6dB，輸入及輸出反射損耗分別大於10.8dB及10.5dB，隔離度大於50dB。
第四個為CSSDA寬頻放大器，製作於厚度1.6mm的FR4 印刷電路板上，偏壓在VDS=2V、IDS=10.6mA時，於0.5~6GHz量得增益為21.5±3.5dB，輸入及輸出反射損耗分別大於8.5dB及11dB，隔離度大於50dB。

關鍵字

分散式 ； 寬頻放大器

並列摘要

Circuits with cost efficiency, flat frequency response and high frequency are required in wideband systems, such as optical communication, ultra-wide band (UWB) communication and the radio astronomy telescope. The designs of such circuits become important research topics recently. This dissertation includes the design methodology and implementation of microwave distributed amplifiers.
The purpose of this dissertation is using distributed configurations to design wideband amplifiers. The basic operation and fundamental principles of the amplifiers are reviewed. The noise and power performances of the amplifiers are also discussed. Then we discussed two kinds of broadband amplifier configurations. One is the conventional distributed amplifier (CDA), and the other is the cascaded single-stage distributed amplifier (CSSDA).
Four circuits are proposed in this thesis. All of them are implemented using packaged discrete transistors on a FR4 PCB.
The first is a 2.4GHz single-stage amplifier. This is an amplifier with the most basic and simple configuration. The amplifier is fabricated on a 0.6-mm thick FR4 PCB. When the bias is VCE=3V and IC=10mA, at 2.4GHz, the measured gain is 6.6dB, and the input return loss is 31.4dB, and the output return loss is 30.1dB, and the isolation is 16dB.
The second is a two-stage wideband amplifier. It is fabricated on a 1.6-mm thick FR4 PCB. When the bias is VDS=4V and IDS=43.1mA, around the 0.5-3GHz, the measured gain is 10.1±1.4dB, and the input return loss is better than 9.1dB, and the output return loss is better than 12.4dB, and the isolation is better than 20dB.
The third is a four-stage wideband amplifier. It is fabricated on a 1.6-mm thick FR4 PCB. When the bias is VDS=4V and IDS=94.8mA, in the 0.5-3GHz range, the measured gain is 15.1±1.6dB, and the input return loss is better than 10.8dB, and the output return loss is better than 10.5dB, and the isolation is better than 50dB.
The fourth is a CSSDA wideband amplifier. It is fabricated on a 1.6-mm thick FR4 PCB. When the bias is VDS=2V and IDS=10.6mA, about the 0.5-6GHz range, the measured gain is 21.5±3.5dB, and the input return loss is better than 8.5dB, and the output return loss is better than 11dB, and the isolation is better than 50dB.

並列關鍵字

distributed ； broadband amplifiers

參考文獻

[1] G. Gonzalez, “Microwave Transistor Amplifiers Analysis and Design,” ed., Prentice-Hall, Inc., 1997.

[2] D. M. Pozar, “Microwave Engineering,” ed., John Wiley & Sons, Inc., 2005.

[3] J. Rollet, “Stability and Power-Gain Invariants of Linear Twoports,” IRE Transactions on Circuit Theory, vol. 9, issue 1, pp. 29-32, March 1962.

[4] D. K. Shaffer and T. H. Lee, “A 1.5-V, 1.5-GHz CMOS low noise amplifier,” IEEE J. Solid-State Circuits, vol. 32, pp. 745-759, June 1997.

[5] B. Razavi, “RF Microelectronics,” Prentice-Hall, Inc., 1998.