超寬頻低雜訊放大器設計

Design of Ultra-Wideband Low-Noise Amplifers

江世華(Shih-Hua Chiang)

指導教授 ： 王多柏

國立臺北科技大學/電資學院/電腦與通訊研究所/碩士(2012年)

摘要

在無線通訊系統中，低雜訊放大器是不可或缺的關鍵性元件。因此，如何設計具有低雜訊與高增益的放大器是一個值得探討的重點。
本論文研究的重點分為三大部分，第一部份超寬頻使用微機電電感之低雜訊放大器是使用TSMC 0.18-μm Mixed Signal RF CMOS MEMS製程來設計與實現。此顆晶片下線時配合CIC微機電後製程，利用電漿反應離子將電感下方基板腐蝕掉，使電感成懸浮狀態。有效提升電感品質因數，進而提升超寬頻低雜訊放大器的增益與降低雜訊指數。第二部份使用交叉耦合對之寬頻差動低雜訊放大器是使用TSMC 0.18-μm Mixed Signal RF CMOS製程來設計與實現。為了再更進一步增強低雜訊放大器增益，我們亦提出寬頻低雜訊放大器電路中加入交錯耦合對來增加增益。第三部份超寬頻使用變容器實現多頻帶抑制之低雜訊放大器是使用TSMC 0.18-μm Mixed Signal RF CMOS製程來設計與實現。此晶片設計首要目的係使用變容器與主動式電感組合成可調整頻帶之帶拒濾波器，進而實現多頻帶抑制的超寬頻低雜訊放大器。利用控制電壓來調整變容器的容值，可以有效調整放大器操作頻帶，並且同時有效抑制0.9 GHz、1.8 GHz、2.4 GHz、5.2 GHz等干擾頻帶。

關鍵字

超寬頻低雜訊放大器 ； 微機電製程 ； 差動低雜訊放大器 ； 交叉耦合對 ； 變容器 ； 主動式電感

並列摘要

Low noise amplifier is a critical component in the wireless communication system, hence how to design an amplifier with low noise and high power gain is a important issue.
This thesis is divided into three parts. In the first part, an ultra wideband low noise amplifier using micromachined inductor is design in 0.18-?m TSMC Mixed Signal RF CMOS MEMS technique. To overcome severe quality factor degradation, a 0.18-?m CMOS compatible post-process is utilized in this work. With the undercut created by the plasma reactive ion etching, the Si substrate underneath the spiral coils was removed, leaving a suspended inductor structure on the wafer surface. The power gain will be enhanced and noise figure will be improved as well due to quality factor be improved. In the second part, the wideband differential low noise amplifier with cross-coupled pair is design in 0.18-?m TSMC Mixed Signal RF CMOS technique. For further improvement in the power gain, the cross-coupled pair is utilized in this work. In the third part, the variable capacitor was employed to accomplish the multiband rejection in this low noise amplifier design. The notch frequency is determined by the active inductor and accumulation varactor for multiband rejection which covered over the main interference band including 0.9, 1.8, 2.4, and 5.2 GHz.

並列關鍵字

Ultra-Wideband Low-Noise Amplifers ； MEMS process ； Varactor ； Differential Low-Noise Amplifers ； Cross-Coupled Pair ； Active Inductors

參考文獻

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