Design strategies for electrically small antennas, actively matched with non-foster elements

255 Pages·2017·5.97 MB·English

www.uc3m.es
DOCTORAL THESIS
DESIGN STRATEGIES FOR
ELECTRICALLY SMALL ANTENNAS,
ACTIVELY MATCHED WITH
NON-FOSTER ELEMENTS
Author:
Luis Fernando Albarrac´ın-Vargas
Advisor:
Daniel Segovia Vargas
DEPARTMENT OF SIGNAL THEORY AND
COMMUNICATIONS
Legan´es, July 18th of 2017

DOCTORAL THESIS
DESIGN STRATEGIES FOR ELECTRICALLY
SMALL ANTENNAS, ACTIVELY MATCHED
WITH NON-FOSTER ELEMENTS
Author: Luis Fernando Albarrac´ın-Vargas
Advisor: Dr. Daniel Segovia-Vargas
Firma del Tribunal Calificador:
Firma
Presidente: Prof. Miloˇs Maz´anek
Secretario: Prof. Luis Enrique Garc´ıa-Mun˜oz
Vocal: Prof. Marco A. Antoniades
Calificaci´on:
Legan´es, July 18th of 2017

A mi familia.

La vida no es la que uno vivi´o,
sino la que uno recuerda,
y c´omo la recuerda para contarla.
What matters in life is not what happens to you
but what you remember and how you remember it.
Gabriel Garc´ıa-Ma´rquez

CONTENTS
Contents vii
Agradecimientos / Acknowledgements xi
Resumen xiii
Abstract xv
Terms and Abbreviations xvii
Preface xxi
1. Introduction 1
1.1. Description of the Problem . . . . . . . . . . . . . . . . . 1
1.1.1. Definition of an Electrically Small Antenna (ESA) 2
1.2. Typical Applications of ESAs . . . . . . . . . . . . . . . . 3
1.3. Fundamental Performance Properties of an ESA . . . . . 5
1.4. Active Circuits Applied to Impedance Matching. . . . . . 9
1.4.1. Possible Applications of Actively Matched Small
Antennas . . . . . . . . . . . . . . . . . . . . . . . 12
1.5. Motivation, Objectives and Contribution . . . . . . . . . . 13
1.6. Organization of the Dissertation . . . . . . . . . . . . . . 14
2. Impedance Matching Techniques for ESAs: Background 17
2.1. Fundamental Parameters of Antennas . . . . . . . . . . . 17
2.1.1. Radiation Pattern . . . . . . . . . . . . . . . . . . 17
2.1.2. Directivity . . . . . . . . . . . . . . . . . . . . . . 19
2.1.3. Gain . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.1.4. Effective Aperture Area and Aperture Efficiency . 21
2.1.5. Phase Pattern and Phase Center . . . . . . . . . . 22
2.1.6. Polarization . . . . . . . . . . . . . . . . . . . . . . 22
2.1.7. Input Impedance . . . . . . . . . . . . . . . . . . . 23
2.1.8. Radiation Resistance . . . . . . . . . . . . . . . . . 23
2.1.9. Bandwidth . . . . . . . . . . . . . . . . . . . . . . 24
2.2. A Brief History of Electrically Small Antennas . . . . . . 25
2.3. Classification and Most Typical ESA Structures. . . . . . 27
2.4. Performance Characteristics of ESAs . . . . . . . . . . . . 28
2.4.1. Antenna Impedance of an ESA . . . . . . . . . . . 29
2.4.2. Quality factor Q . . . . . . . . . . . . . . . . . . . 31
2.4.3. Bandwidth and Passive Matching . . . . . . . . . . 34
2.4.4. Radiation efficiency . . . . . . . . . . . . . . . . . 36
2.5. Passive Impedance Matching Constraints . . . . . . . . . 36
2.6. Impedance Matching Using Active & non-Foster Networks 39
2.6.1. Tunable Antennas Technique . . . . . . . . . . . . 41
2.6.2. Non-Foster Impedance Matching: Concept. . . . . 43
2.6.3. Foster’s Reactance Theorem and non-Foster
Elements . . . . . . . . . . . . . . . . . . . . . . . 45
2.7. Transistor-based Non-Foster Elements: Realizations . . . 47
2.7.1. Negative Impedance Converters (NICs) . . . . . . 47
2.7.2. Negative Impedance Inverters (NIIs) . . . . . . . . 53
2.8. Negative Impedance Converters for ESAs . . . . . . . . . 58
2.8.1. Cascade and Series Topologies . . . . . . . . . . . 58
2.8.2. Embedded non-Foster Matching Networks . . . . . 64
3. Embedded Non-Foster Matching Networks for ESAs 67
3.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 67
3.2. Two-Port Antenna Approach for Active Impedance
Matching . . . . . . . . . . . . . . . . . . . . . . . . . . . 69