Differential Antennas: Theory and Practice

✍ Scribed by Yueping Zhang

• Publisher: Wiley-IEEE Press
• Year: 2024
• Tongue: English
• Leaves: 355
• Edition: 1
• Category: Library

✦ Synopsis

A comprehensive introduction to the theory and practice of differential antennas

The first antennas ever created were differential antennas, in the dipole and loop constructions, before the subsequent creation of the single-ended or monopole antenna. Dozens of basic antenna configurations have been invented since then, the majority of them differential. The theory and design of differential antennas therefore has an impact on a huge range of fields which make use of electromagnetic waves.

Differential Antennas contains a thorough, comprehensive overview of these antennas, their theory, and their practical applications. It details the relationship between differential and single-ended antennas, which may act as tools for determining the properties of one when the other is known. This book offers an analysis of the role differential antennas play in wireless communication and sensing. Overall, it stands as an essential contribution to a key area of communications technology.

Differential Antennas readers will also find:

• Chapters covering topics including microstrip antennas, shorted patch antennas, grid array antennas, and other designs
• Tables and figures illustrating key data, antenna structures, and more
• Instructions for measuring differential antennas for characterization and specification purposes

Differential Antennas is ideal for senior and graduate level students, researchers, and radio frequency engineers.

✦ Table of Contents

Cover
Series Page
Title Page
Copyright Page
Dedication Page
Contents
About the Author
Preface
Acknowledgments
Chapter 1 Introduction
1.1 Background
1.2 Balanced and Unbalanced Antennas
1.3 Even and Odd Modes
1.4 Differential and Single-Ended. Circuits
1.5 An Important Ratio
1.6 Mixed-Mode. S-Parameters
1.7 Balun
1.8 Concluding Remarks
References
Chapter 2 Differential Wire Antennas
2.1 Introduction
2.2 Dipole and Monopole Antennas
2.3 Folded Dipole and Monopole Antennas
2.4 Loop and Half-Loop. Antennas
2.5 Loop-Dipole. and Half-Loop-Monopole. Antennas
2.6 Yagi-Uda. and Half-Yagi-Uda. Antennas
2.7 Concluding Remarks
References
Chapter 3 Differential Slot Antennas
3.1 Introduction
3.2 Slot and Half-Slot. Antennas
3.2.1 Input Impedances
3.2.2 Radiation Characteristics
3.3 Self-Complementary. Antennas
3.4 Yin-Yang. Antennas
3.4.1 Basic Differential Structure
3.4.2 The Array Model and the Distribution of Current
3.4.3 Electromagnetic Field
3.4.4 The Input Impedance
3.4.5 Radiation Characteristics
3.4.6 Basic Single-Ended. Structure
3.5 Concluding Remarks
References
Chapter 4 Differential Microstrip Patch Antennas
4.1 Introduction
4.2 Cavity Model
4.2.1 Electrically Thin or Thick Substrate
4.2.2 Fields in the Cavity
4.2.3 Radiation Fields
4.2.4 Polarization
4.2.5 Directivity and Radiation Efficiency
4.2.6 Input Impedances
4.2.7 Reflection Coefficients
4.2.8 Resonance and Electrical Separation
4.2.9 Quality Factor and VSWR Bandwidth
4.3 Rectangular Patch
4.3.1 Resonant Modes
4.3.2 Resonant Frequencies
4.3.3 Radiation Characteristics
4.3.3.1 Radiated Fields
4.3.3.2 Cross Polarization
4.3.3.3 Radiation Conductance and Directivity
4.3.3.4 Radiation Efficiency and Effective Loss Tangent
4.3.4 Impedance Characteristics
4.3.4.1 Differential Input Impedance
4.3.4.2 Fundamental Resonance and Electrical Separation
4.3.4.3 Resonant Differential Input Resistance
4.3.5 Quality Factor
4.3.6 Differential Versus Single-Ended. Rectangular Microstrip Patch.Antennas
4.3.6.1 Excitation and Suppression of Resonant Modes
4.3.6.2 Input Impedance Ratio
4.3.6.3 Reduction of Cross-Polarized. Radiation
4.3.6.4 Performance Improvement
4.3.7 Design Procedure
4.4 Circular Patch
4.4.1 Resonant Modes
4.4.2 Resonant Frequencies
4.4.3 Radiation Characteristics
4.4.3.1 Radiated Fields
4.4.3.2 Cross Polarization
4.4.3.3 Radiation Conductance and Directivity
4.4.3.4 Radiation Efficiency and Effective Loss Tangent
4.4.4 Impedance Characteristics
4.4.4.1 Differential Input Impedance
4.4.4.2 Fundamental Resonance and Electrical Separation
4.4.4.3 Resonant Differential Input Resistance
4.4.5 Quality Factor
4.4.6 Differential Versus Single-Ended. Circular Microstrip Patch.Antennas
4.4.6.1 Excitation and Suppression of Resonant Modes
4.4.6.2 Input Impedance Ratio
4.4.6.3 Reduction of Cross-Polarized. Radiation
4.4.6.4 Axial Ratio Improvement
4.4.7 Design Procedure
4.4.7.1 Design for Linear Polarization
4.4.7.2 Design for Circular Polarization
4.5 Stacked Patch
4.5.1 Quasi-Even. and Odd Modes
4.5.2 Resonant Frequencies
4.5.3 Design and Optimization
4.5.4 Design Examples
4.5.5 Results and Discussion
4.6 Patch Arrays
4.6.1 Feed Networks
4.6.2 Mutual Coupling
4.6.3 Reduction of Mutual Coupling
4.6.3.1 Modification to the Patch, Substrate, or Ground Plane
4.6.3.2 Integration of Electromagnetic Bandgap Structures
4.6.3.3 Utilization of Additional Structures
4.6.4 Design Considerations
4.6.4.1 Frequency Scanning Array
4.6.4.2 Phased Array
4.6.4.2.1 A Differential Architecture from Circuits to Antennas
4.6.4.2.2 The Use of Baluns in the Feed Network
4.7 Applications
4.8 Concluding Remarks
References
Chapter 5 Differential Microstrip Shorted Patch Antennas
5.1 Introduction
5.2 SPA and DSPA
5.2.1 Resonant Modes
5.2.2 Coupling and Resonance
5.2.3 Radiation Characteristics
5.2.4 Frequency Ratio and Size Reduction
5.2.5 Experiment Results
5.3 Modified SPA and DSPA
5.3.1 Radiation Characteristics
5.3.2 Design and Experiment
5.4 PIFA and DPIFA
5.4.1 Analysis and Design
5.4.2 Experiment
5.5 ME and DME Dipoles
5.5.1 Feeding Techniques
5.5.2 Resonant Frequency
5.5.3 Operating Principle
5.5.4 Design of DME Dipole and Array
5.5.5 ME Dipole Array Applications
5.6 Concluding Remarks
References
Chapter 6 Differential Microstrip Slot Antennas
6.1 Introduction
6.2 Resonant Modes
6.3 Excitation of Resonant Modes
6.4 Half-Wavelength. Microstrip Slot Antenna
6.5 Full-Wavelength. Microstrip Slot Antenna
6.6 Concluding Remarks
References
Chapter 7 Differential Microstrip Grid Array Antennas
7.1 Introduction
7.2 Basic Configuration
7.3 Principle of Operation
7.4 Fundamental Characteristics
7.4.1 Resonant Frequency
7.4.2 Impedance Bandwidth
7.4.3 Half-Power. Beamwidth
7.4.4 Gain
7.4.5 Gain Bandwidth
7.5 Differential Excitation
7.6 Design Procedure, Formulas, and Examples
7.7 An Impedance Matching Technique
7.8 A Slow-Wave. Structure
7.9 Dual Current Modes
7.10 Co-Aperture. Dual Bands
7.11 Applications
7.11.1 60-GHz. Radios
7.11.2 79-GHz. Radars
7.11.3 Full Duplex Radios and MIMO Systems
7.11.4 RF Energy Harvester and Wireless Power Transfer
7.12 Concluding Remarks
References
Chapter 8 Differential Printed Antennas
8.1 Introduction
8.2 Quasi-Yagi. Antennas
8.2.1 Surface Wave
8.2.1.1 Guided by Grounded Dielectric Substrate
8.2.1.2 Guided by Ungrounded Dielectric Substrate
8.2.2 Design of Differential Quasi-Yagi. Antenna
8.2.3 Quasi-Yagi. Antenna Arrays
8.2.3.1 Mutual Coupling
8.2.3.2 Decoupling Structures and Effects
8.3 Fractal Antennas
8.3.1 The Sierpinski Gasket Monopoles
8.3.1.1 Original Sierpinski Gasket Monopole
8.3.1.2 Design Formulas
8.3.1.3 A Sierpinski Gasket Monopole Fed by a Microstrip Line
8.3.2 The Sierpinski Gasket Dipoles
8.4 Spiral Antennas
8.4.1 The Equiangular Spiral Antenna
8.4.1.1 Frequency Independence
8.4.1.2 Current Distributions
8.4.1.3 Input Impedance
8.4.1.4 Radiation Patterns
8.4.1.5 Gain
8.5 Applications
8.6 Concluding Remarks
References
Chapter 9 Differential Antenna Measurements
9.1 Introduction
9.2 Impedance
9.2.1 The S-Parameters. Method
9.2.2 The Balun Method
9.2.2.1 A 180o Power Divider as the Balun
9.2.2.2 A 180o Hybrid Coupler as the Balun
9.2.3 The Mixed-Mode. S-Parameters. Method
9.2.4 Comparison of the Methods
9.3 Efficiency
9.3.1 The Wheeler Cap Method
9.3.2 The Source-Stirred. Chamber Method
9.4 Radiation Pattern
9.5 Gain
9.6 Concluding Remarks
References
Index
EULA