This book presents the proposal for the novel designs of the wideband Magneto-Electric (ME) dipole antenna for various applications in wireless communication. The standard ME dipole consists of a planar dipole, which acts like an electric dipole, and a vertically oriented quarter wave shorted patch, equivalent to a magnetic dipole. The research demonstrates the good electrical characteristics for the proposed designs of the wideband ME dipole antenna and shows low cross-polarization radiations, stable antenna gain across the operating frequency band and almost identical radiation patterns in the E- plane and H-plane. Literature confirms the design of the ME dipole antenna as linearly polarized, circularly polarized or differentially fed antenna and this thesis presents five novel structures of ME dipole antenna for applications like airborne radar, Ultra-Wide Band (UWB), mobile communication and satellite communication. After examining a number of feeding techniques designed to enhance the impedance bandwidth of ME dipole antenna, which includes co-axial-to-patch probe feeding, transition of microstrip-to-parallel strip line feeding, differential feeding, the book presents all the novel designs using co-axial probe feeding.
Table of Contents
Chapter 1 Introductory Chapter
1.1 Introduction
1.2 Review of Previous Research
1.2.1 Wideband unidirectional patch antenna
1.2.2 Bandwidth Enhancement Techniques for Conventional unidirectional Microstrip Patch Antenna
1.2.2.1 U-slot Technique
1.2.2.2 L-shaped Probe Technique
1.2.3 The Dipole Antenna
1.2.3.1 Bandwidth Enhancement Techniques for Dipole Antenna
1.2.4 Complementary Antenna
1.2.4.1 Complementary Antenna Composed of Slot Antenna and Parasitic Wires
1.2.4.2 Complementary Antenna Composed of Slot Antenna and a Monopole
1.2.5 Magneto-Electric Dipole Antenna
1.2.5.1 Magneto-Electric Dipole Antenna with Modified Ground Plane
1.2.5.2 Magneto-Electric Dipole Antenna with Differential Feed
1.2.5.3 Circularly Polarized Magneto-Electric Dipole Antenna
1.2.5.4 Planar Printed Magneto-Electric Dipole Antenna
1.2.5.5 Reconfigurable Magneto-Electric Dipole Antenna
1.2.5.6 Millimeter Waves Magneto-Electric Dipole Antenna
1.3 Objectives
1.4 Structure of the Book
Chapter 2 Design of an End-Fire Magneto-Electric Dipole Antenna
2.1 Introduction
2.2 Antenna Description and Design Geometry
2.3 Current Distribution in the Magneto-Electric Dipole Antenna
2.4 Simulation and Measured Results
2.5 Parametric Study
2.5.1 Effect of Variation in length of Capacitive Arm
2.6 Conclusion
Chapter 3 Design of a Differentially-fed Magneto-Electric Dipole Antenna
3.1 Introduction
3.2 Electrical Parameters of Differentially fed Antenna
3.3 Antenna Description and Design Geometry
3.4 Simulation and Measured Results
3.5 Conclusion
Chapter 4 Design of Magneto-Electric Dipole Antenna with Modified Ground Plane
4.1 Introduction
4.2 Principle of Operation
4.3 Design of E-Shaped Antenna without Cavity
4.4 Performance of E-Shaped Antenna without Cavity
4.5 E-Shaped Antenna with Rectangular Cavity Reflector
4.5.1 Effect of Height of Rectangular Cavity
4.5.2 Effect of Width of Rectangular Cavity
4.6 Simulation and Measurement Results
4.7 Conclusion
Chapter 5 Design of a Planar Circularly Polarized Magneto-Electric Dipole Antenna
5.1 Introduction
5.2 Antenna Geometry and Design
5.3 Current Distribution
5.4 Simulations and Measurements
5.5 Parametric Study
5.5.1 Effect of Length of ground Plane
5.5.2 Effect of Width of ground Plane
5.5.3 Effect of Width of Feed Line
5.6 Conclusion
Chapter 6 Design of a Magneto-Electric Monopole Antenna
6.1 Introduction
6.2 Antenna Design and Geometry
6.3 Current Distribution
6.4 Analysis of Magneto-Electric Monopole Antenna
6.5 Simulation and Measurement Results Analysis
6.6 Parametric Study
6.6.1 Effect of Height of Monopole Antenna
6.6.2 Effect of length of Feed of Monopole Antenna
6.6.3 Effect of Width of Ground Plane
6.6.4 Effect of Length of Ground Plane
6.10 Conclusion
Chapter 7 Concluding Remarks
Research Objectives and Themes
This thesis focuses on the advancement of high-performance, wideband, and low-profile antenna systems, specifically investigating novel classes of Magneto-Electric (ME) dipole and monopole antennas. The primary objective is to design and analyze antenna configurations that provide stable gain, wide impedance bandwidth, and nearly identical E-plane and H-plane radiation patterns, suitable for various modern wireless communication applications ranging from airborne radar to satellite and mobile communications.
- Development of end-fire ME dipole antennas for airborne radar applications.
- Implementation of wideband, differentially-fed ME dipole antenna structures for UWB systems.
- Enhancement of gain characteristics through modified ground plane and cavity designs.
- Exploration of circularly polarized planar antenna designs for X-band applications.
- Design and optimization of ME monopole antennas to achieve size reduction and multiband operation.
Excerpt from the Book
1.2.4 The Complementary Antenna
The concept of complementary antenna consisting of an electric dipole and a magnetic dipole caught an attraction to achieve an equal E-plane and H-plane radiation pattern along with stable performance over the frequency range [52]. According to the law of electromagnetic theory, an electric dipole shows a figure eight radiation pattern in E-plane and a figure O pattern in the H-plane; while a magnetic dipole shows figure O radiation pattern in the E-plane and a figure eight radiation pattern in the H-plane. Simultaneous excitation of both electric dipole and magnetic dipole, with an appropriate amplitude and suitable phase difference, a unidirectional radiation pattern with equal E-plane and H-plane can be obtained. The practical implementation of this antenna was proposed in 1974 [53]. Another design, having a passive dipole, placed in front of a slot, was reported [54]. The technique, based on a slot and dipole combination, was realized by many investigators [55-57], however, all of these designs [52-57] suffer from serious drawback of either having narrow bandwidth or possessing a bulky structure.
Chapter Summaries
Chapter 1 Introductory Chapter: This chapter provides an overview of microstrip patch antennas and the evolution towards ME dipole antennas, highlighting their wideband characteristics and potential for modern wireless communications.
Chapter 2 Design of an End-Fire Magneto-Electric Dipole Antenna: A novel wideband antenna with end-fire radiation capabilities for airborne radar applications is introduced, utilizing a Z-shaped feed design.
Chapter 3 Design of a Differentially-fed Magneto-Electric Dipole Antenna: This chapter details an improved broadside ME dipole antenna designed for UWB applications that eliminates the need for bulky off-chip baluns.
Chapter 4 Design of Magneto-Electric Dipole Antenna with Modified Ground Plane: The design of a broadband, linearly polarized ME dipole antenna with a rectangular cavity reflector is presented to achieve enhanced gain and stable performance.
Chapter 5 Design of a Planar Circularly Polarized Magneto-Electric Dipole Antenna: This chapter demonstrates a pioneering planar circularly polarized ME dipole antenna designed for X-band applications.
Chapter 6 Design of a Magneto-Electric Monopole Antenna: An effort to reduce the size of the ground plane is explored through the introduction of an unsymmetrical E-shaped electric monopole antenna for C-band applications.
Chapter 7 Concluding Remarks: The concluding chapter summarizes the key achievements in wideband antenna research and highlights the potential of the proposed designs for integration into high-performance antenna arrays.
Keywords
Magneto-Electric Dipole, UWB, Wideband Antenna, End-Fire Radiation, Differentially-fed, Circular Polarization, X-Band, C-Band, Microstrip Patch Antenna, Ground Plane Modification, Impedance Bandwidth, Antenna Efficiency, Radiation Pattern, Wireless Communication, Antenna Array.
Frequently Asked Questions
What is the primary focus of this research?
The research focuses on the development and optimization of various classes of Magneto-Electric (ME) dipole and monopole antennas to meet the increasing demand for wideband, low-profile, and high-gain antenna systems in wireless communications.
Which key antenna types are covered in this work?
The thesis covers several types of antennas, including end-fire ME dipole antennas, differentially-fed ME dipole antennas, planar circularly polarized ME dipole antennas, and ME monopole antennas.
What is the main goal of the proposed designs?
The primary goal is to achieve stable antenna gain, wide impedance bandwidth, and symmetrical E-plane and H-plane radiation patterns, while maintaining low cross-polarization and low back-lobe radiation across the operating frequency bands.
What scientific methodology is utilized in this study?
The research relies on numerical simulations using the Method of Moments (MoM) via the IE3D software, followed by physical fabrication and experimental validation using vector network analyzers (VNA) and measurement systems.
What is covered in the main section of the thesis?
The main sections systematically progress through different antenna designs, providing geometrical descriptions, theoretical analyses of the feeding structures, results for impedance and gain, and parametric studies for each design.
Which keywords characterize this thesis?
Key terms include Magneto-Electric Dipole, Ultra-Wideband (UWB), Circular Polarization, Impedance Bandwidth, Radiation Pattern, and Antenna Array, among others.
Why is a Z-shaped feed used in Chapter 2?
The Z-shaped feed is introduced to achieve an end-fire radiation pattern by counterbalancing the capacitive and inductive reactances, which is particularly suitable for airborne radar applications.
What are the advantages of a differentially-fed antenna?
Differentially-fed structures offer benefits such as common-mode rejection, low mutual coupling, reduced harmonic interference, and the elimination of bulky off-chip baluns, leading to more compact designs.
What novelty does the antenna in Chapter 5 provide?
Chapter 5 presents the first true planar circularly polarized magneto-electric dipole antenna specifically designed for X-band satellite and radar communication applications.
- Quote paper
- Neetu Marwah (Author), 2021, The Perspective of Magneto-Electric Dipole Antennas, Munich, GRIN Verlag, https://www.grin.com/document/1139999
