Table Of Content

Antenna Design for Cognitive Radio For a complete listing of titles in the Antennas and Electromagnetics Analysis Library, turn to the back of this book. Antenna Design for Cognitive Radio Youssef Tawk Joseph Costantine Christos Christodoulou Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the U.S. Library of Congress. British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library. Cover design by John Gomes ISBN 13: 978-1-60807-953-7 © 2016 ARTECH HOUSE 685 Canton Street Norwood, MA 02062 All rights reserved. Printed and bound in the United States of America. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the publisher. All terms mentioned in this book that are known to be trademarks or service marks have been appropriately capitalized. Artech House cannot attest to the accuracy of this information. Use of a term in this book should not be regarded as affecting the validity of any trademark or service mark. 10 9 8 7 6 5 4 3 2 1 Contents Preface xi 1 Introduction to Cognitive Radio 1 1.1 Why Cognitive Radio? 1 1.2 Towards a Cognitive Radio 2 1.3 Spectrum Interweave and Underlay 4 1.4 The Cognitive Radio Cycle of Actions (ODAL) 8 1.5 The Observe Part of a Cognitive Radio Cycle 9 1.5.1 Interweave Mode 9 1.5.2 Underlay Mode 10 1.6 The Decide Part of a Cognitive Radio Cycle 11 1.6.1 Interweave Mode 12 1.6.2 Underlay Mode 12 1.7 The Act Part of a Cognitive Radio Cycle 12 1.7.1 Interweave Mode 14 1.7.2 Underlay Mode 14 1.8 The Learn Part of a Cognitive Radio Cycle 14 v vi Antenna Design for Cognitive Radio Contents vii 1.8.1 Interweave Mode 15 1.8.2 Underlay Mode 15 1.9 Discussion 15 References 16 2 Software-Defined Radio and Cognitive Radio: A Systems Overview 21 2.1 Introduction 21 2.2 What Is Software-Defined Radio? 22 2.3 Wireless Transceiver Architectures 24 2.3.1 Single-Band Architectures 24 2.3.2 Multiband Architectures 26 2.3.3 Software-Defined Radio Architectures 28 2.4 Cognitive Radio Architectures 31 2.5 Tunable Analog RF Components 34 2.5.1 Tunable Bandpass Filters 35 2.5.2 Tunable Power Amplifiers 36 2.6 Discussion 38 References 38 3 Antenna Design Requirements for Cognitive Radio 43 3.1 Introduction 43 3.2 Antenna Parameters 44 3.2.1 Reflection Coefficient 44 3.2.2 Realized Gain 46 3.2.3 Radiation Pattern 46 3.2.4 Quality Factor 47 3.3 Antenna Design Limitations 48 3.4 Antenna Design Specifications for Cognitive Radio 51 3.4.1 Mobile Terminals 52 3.4.2 Spectrum Interweave Cognitive Radio 53 3.4.3 Spectrum Underlay Cognitive Radio 56 vi Antenna Design for Cognitive Radio Contents vii 3.5 Antenna Design for Cognitive Radio Antenna Systems Using Reconfigurable Filters 57 3.6 Comparison Between the Antenna Design Requirements for the Spectrum Interweave and Underlay Cognitive Radio 59 3.7 Antenna Design Limitations for Cognitive Radio Interweave and Underlay 60 3.8 Discussion 61 References 62 4 Wideband-Sensing Antennas for Cognitive Radio 65 4.1 Introduction 65 4.2 History of UWB Antennas 66 4.3 Categories of UWB Antennas 67 4.4 Frequency-Independent Antennas 69 4.4.1 Printed Spiral Antenna 70 4.5 Nonplanar UWB Antennas 73 4.6 Planar UWB Antennas 75 4.6.1 Miniaturized Triangular Sheet Antenna 77 4.6.2 Planar UWB Monopole 78 4.7 Printed UWB Antennas 84 4.8 Printed UWB Slot Antennas 88 4.9 Printed UWB Horn Antennas 89 4.9.1 Coplanar Vivaldi Antenna 90 4.9.2 Antipodal Vivaldi Antenna 91 4.10 Printed UWB Antenna with Notches 93 4.10.1 Printed UWB Antenna with Fixed Notches 93 4.10.2 Printed UWB Antenna with Reconfigurable Notches 96 4.11 Discussion 99 References 100 viii Antenna Design for Cognitive Radio Contents ix 5 Communicating Reconfigurable Antennas for Cognitive Radio 107 5.1 Introduction 107 5.2 Overview of Reconfigurable Antennas 108 5.3 Antenna Reconfiguration Using RF MEMS 113 5.4 Antenna Reconfiguration Using PIN Diodes 117 5.5 Antenna Reconfiguration Using Varactors 123 5.6 Antenna Reconfiguration Using Thermal-Switching Components 129 5.7 Antenna Reconfiguration Using Optical Photoconductive Switches 131 5.8 Graph Modeling Switch-Reconfigurable Antennas for Redundancy Reduction 135 5.9 Antenna Reconfiguration Using Mechanical Actuators 137 5.10 Antenna Reconfiguration Using Material Change 140 5.11 Implementation of Reconfigurable Antennas in Spectrum Interweave Cognitive Radio 145 5.12 Analysis of Reconfigurable Antennas in Cognitive Radio 154 5.13 Discussion 154 References 155 6 Reconfigurable Filtennas for Cognitive Radio 163 6.1 Introduction 163 6.2 Design of Microwave Filters 164 6.3 Printed Transmission Line Characteristics 170 6.4 Bandpass Filter Designs 172 6.5 Bandstop Filter Designs 174 6.6 Ultrawideband Filter Designs 176 viii Antenna Design for Cognitive Radio Contents ix 6.7 Reconfigurable Filters 179 6.8 Reconfigurable Filtennas 185 6.9 Discussion 187 References 189 7 Implementation of MIMO Antennas on Cognitive Radio 193 7.1 Introduction 193 7.2 Modeling the Propagation Effects 194 7.3 MIMO Antenna Basics 196 7.4 Isolation Improvement in MIMO Antenna Systems 201 7.5 Reconfigurable MIMO Antenna Structures 205 7.6 MIMO Antennas for Cognitive Radio 212 7.7 Discussion 217 References 218 8 Machine-Learning Implementation in Cognitive Radio 221 8.1 Introduction 221 8.2 Categories of Machine-Learning Algorithms 222 8.3 Basic Review of Neural Networks 223 8.3.1 Neural Network Concepts 223 8.3.2 Neural Network Learning Connections’ Weights 224 8.3.3 Back-Propagation Learning 225 8.3.4 Mathematical Model of a Neural Network 225 8.4 Neural Network FPGA Controller Design 227 8.4.1 Neural Network Modeling Procedure 228 8.5 Neural Network Implementation 229 8.5.1 Neural Network Modeling of a Reconfigurable Antenna Based on PIN Diodes 230 8.5.2 Neural Network Modeling of a Varactor-Based Reconfigurable Filtenna 232