MOSFET雜訊分析及其低雜訊電路的應用

Abstract

本篇論文包含兩個部份：第一部份討論PCSNIM架構下，低雜訊放大器最佳化設計的方法。有別於傳統PCSNIM的設計方法是先固定電流，本篇論文提出固定電流密度的設計方法，而使用此方法將遭遇如何選擇最佳元件尺寸的問題，因此必須掌握各不同尺寸的MOSFET元件之雜訊參數。為了實際應用於低雜訊放大器設計，針對TSMC 0.18m CMOS製程之MOSFET元件進行雜訊參數萃取，並配合低雜訊放大器的雜訊公式得到最佳化設計的方法。 論文第二部分主要為探討適用於各種常見通訊系統之低雜訊電路實作，所有電路皆採用TSMC 0.18m SiGe BiCMOS製程技術實現。首先實作應用於WLAN系統中，2.4GHz與5.8GHz雙頻帶共存式低雜訊放大器，藉由將三個電感纏繞在一起達到縮小面積的效果。另外也實作了應用於UWB系統中的超寬頻放大器，使用Chebyshev帶通濾波器的方式，以達到足夠的頻寬。最後，實作應用於DBS系統中的Ku頻段低雜訊降頻器，利用被動混頻器的特性，有效的降低低雜訊降頻器的功率消耗。

This thesis is mainly classified into two major parts. On the first part, we discuss how to optimize the design of a low noise amplifier (LNA) by PCSNIM technique. Unlike conventional PCSNIM design, which fixes the current first, we provide a method which fixes the current density first. This method will encounter the problem of choosing the optimal device size, so being aware of noise parameters under different sizes of MOSFET device is essential. To practically apply to the LNA design, we extract the noise parameters of MOSFET device using TSMC 0.18m CMOS process technology, and with the noise formulas of the LNA, we can develop the optimal method. On the second part, we focus on low noise circuits which are suitable for common communication system applications, and all the circuits are implemented by TSMC 0.18m SiGe BiCMOS process technology. First, we implement a 2.4/5.8-GHz concurrent dual-band LNA which is applied to a WLAN system, and the area can be minimized by wrapping these three inductors together. Second, we also implement an ultra-wideband low noise amplifier which is applied to a UWB system, and we manage to gain enough bandwidth by using chebyshev bandpass filter. Last, we implement a Ku-band low noise block (LNB) applied to a DBS system, and the power consumption of the LNB can be effectively decreased because of passive mixer’s characteristics.