李泰成臺灣大學：電子工程學研究所陳冠鈞Chen, Guan-JunGuan-JunChen2007-11-272018-07-102007-11-272018-07-102006http://ntur.lib.ntu.edu.tw//handle/246246/57218近年來，隨著無線通訊技術的發達，人們希望能夠隨時隨地傳送資料交換訊息，所以對於頻寬的需求量愈來愈大。然而目前頻譜使用的方式效率並不高。因此，感知無線電系統概念應之而生。感知無線電系統是一種能偵測外界環境變化，並且動態地改變自己的頻寬、調變、功率以及其它參數的無線電系統。所以，此系統能達到最佳的表現與最大的傳輸率。本論文的感知無線電系統應用在5 GHz的UNII頻帶。希望能與該頻帶原主要使用者－802.11a系統共存，並且不打擾到原主要使用者的運作。 此感知無線電系統在運作中需要一個八個頻道多相位濾波器，及即本篇論文的重點。由於初步的試驗與功能的驗證，本論文僅實現中間四個頻道，即四個頻道多相位濾波器。此四個頻道多相位濾波器是由兩個可調式複數濾波器所組成。應用複數濾波器改變中心頻率的技巧與gm-C濾波器改變頻寬的方法。經過適當的組合，就可完成四個頻道多相位濾波器。此濾波器能夠根據系統需求任意選擇不同頻道，並且已在台積電0.18微米製程中實現。With advance in the technology of wireless communication, people are able to transmit data and exchange information anywhere anytime nowadays. Hence the demand on the bandwidth is increasingly higher. However, at present, the frequency spectrum usage is not very efficient, so cognitive radio systems are proposed to solve the issue. This system has capability to sense the environment variances, and dynamically adjusts its bandwidth, modulation, power, and other parameters, in order to achieve optimal performances and maximum transmission rate. The cognitive radio system presented in this thesis is aimed at 5-GHz UNII band. We expect that the system coexists with the primary user, 802.11a, without interference. The cognitive radio system in operation requires a 8-channel poly-phase filter, which is the subject of this thesis. Due to the functional verification and the nature of trial of the research, this thesis only accomplishes the middle 4 channels, 4-channel poly-phase filter. The 4-channel poly-phase filter consists of two programmable complex filters. The programmable center frequency technique of the complex filter and the programmable bandwidth method of the gm-C filter are applied. The 4-channel poly-phase filter can be completed through appropriate combinations. The filter is able to select different channels according to the demand of the system, and has been fabricated in a TSMC 0.18-μm CMOS technology.Chapter 1　Introduction 1 1.1　Motivation and Research Goals 1 1.2　Thesis Overview 2 Chapter 2　Cognitive Radio Systems 3 2.1　Introduction to the Cognitive Radio System 3 2.2　The 4-Channel Poly-Phase Filter 7 Chapter 3　Basic Concepts 9 3.1　Gm-C Filter 9 3.1.1　Modeling of the Gm Cell 9 3.1.2　Resistors 10 3.1.3　Gyrators 11 3.1.4　A Second-order Low-Pass Filter Prototype 13 3.2　Complex Filters 15 3.3　Programmable Bandwidth 17 Chapter 4　Implementation of the 4-Channel Poly-Phase Filter for Cognitive Radio Systems 19 4.1　Architecture of the 4-Channel Poly-Phase Filter 19 4.2　Architecture of the Complex Filter 22 4.3　 Low-Pass Filter Prototype 23 4.3.1　A Chebyshev Low-Pass Filter 23 4.3.2　A Fourth-order Gm-C Low-Pass Filter 24 4.4　Bridge Gyrators 26 4.5　Tunable Gm Cell 27 4.5.1　Controllable Transconductor 27 4.5.2　Tunable Gm Cell 28 4.5.3　Common-Mode Feedback Circuit 30 4.6　Noise and Linearity Requirements 32 4.6.1　Noise 32 4.6.2　Linearity 34 4.7　Automatic Tuning Techniques 36 4.7.1　Gm-CU Frequency Tuning 37 4.7.2　Voltage-Controlled Oscillator Frequency Tuning 39 4.7.3　Voltage-Controlled Filter Frequency Tuning 40 Chapter 5　Simulation and Experimental Results of the 4-Channel Poly-Phase Filter 43 5.1　Simulation Results 43 5.1.1　HSPICE Behavioral Simulation 43 5.1.2　HSPICE Transistor-Level Simulation 45 5.2　Experimental Results 49 5.2.1　Testing Strategies 49 5.2.2　Experimental Results 50 Chapter 6　Conclusions and Discussions 55 6.1　Conclusions 55 6.2　Discussions 56 Bibliography 571338773 bytesapplication/pdfen-US複數濾波器多相位濾波器感知無線電complex filterpoly-phase filtercognitive radio systemthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/57218/1/ntu-95-R93943039-1.pdf