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.
At a glance
- Five antenna structures designed and fabricated for wireless applications across five frequency bands
- Method-of-moments IE3D simulations compared with measurements of a fabricated end-fire antenna
- Cavity reflector study varies height across 32, 34 and 36 mm
- Monopole input impedance derived and plotted using MATLAB
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
Objectives and Topics
This work investigates how magneto-electric antenna structures can be designed for wideband wireless applications while addressing impedance bandwidth, gain, polarization and radiation-pattern requirements. It develops and evaluates dipole and monopole configurations using electromagnetic simulation, prototype fabrication, measurements and parametric analysis.
- Complementary electric and magnetic radiators
- End-fire and differentially fed dipole designs
- Modified ground planes and cavity reflectors
- Planar circular polarization for X-band applications
- Magneto-electric monopole design and equivalent-circuit analysis
Excerpt from the Book
3.3 Antenna Description and Design Geometry
Figure 3.1 represents the photograph of designed and fabricated differentially-fed ME dipole antenna along with 3-D geometry of the proposed feeding structure. Figure 3.2 shows the side view and top view of proposed differentially-fed ME dipole antenna. For the sake of simplicity the geometry of proposed antenna is made symmetric about X-Z and Y-Z planes. All the initial calculations for the proposed antenna have been carried out for a center frequency f0=1.5GHz. The antenna has been designed considering three parts- radiation structure, feeding structure and the ground plane. The radiation structure is designed using vertically oriented quarter wave shorted patch as magnetic dipole and a planar dipole as an electric dipole. The novel feeding structure has been designed in such a manner that it can provide equal excitation to magnetic dipole and electric dipole for wideband impedance matching. The feeding structure has four vertical parallel strips hanging on two sides of horizontal plate to form a pair of front strips and a pair of back strips. The two front vertical strips have been connected via a 9mm wide horizontal copper strip, which is 2mm above the ground plane. A 50ohm SMA connector is placed at the center to make first port. The same process has been repeated for both the vertical strips present in the back and formed the second port. These sets of front and back parallel strips behave like a balanced transmission line. The horizontal plate has been designed to couple the differential signal to the radiating structure. The two SMA ports have been used together to form differential input ports. These differential ports consist of port 1+, where SMA connector 1 is connected and port1-, where SMA connector 2 is connected.
Ground plane and all the parts of the proposed antenna have been made of copper sheet having thickness of 0.3mm. The radius of each of the SMA connector has been chosen as 0.635mm and the length over the ground plane has been chosen as h=2mm. The designed antenna has been optimized and simulated on MOM based IE3D software. The purpose of optimization was to maximize the gain and impedance bandwidth while maintaining the unidirectional as well as stable radiation pattern in the entire range of frequency operation. Table 3.1 gives the optimized geometrical parameters of the proposed antenna.
Chapter Summaries
Chapter 1 Introductory Chapter: The opening chapter reviews patch, dipole and complementary antennas and outlines the objectives of the proposed magneto-electric designs.
Chapter 2 Design of an End-Fire Magneto-Electric Dipole Antenna: This chapter presents a Z-shaped feed and an end-fire antenna intended for airborne radar applications, including design geometry and simulated and measured performance.
Chapter 3 Design of a Differentially-fed Magneto-Electric Dipole Antenna: The chapter develops a differentially fed structure and discusses its electrical parameters, geometry and experimental evaluation.
Chapter 4 Design of Magneto-Electric Dipole Antenna with Modified Ground Plane: An E-shaped antenna is examined with and without a rectangular cavity reflector, including studies of cavity dimensions.
Chapter 5 Design of a Planar Circularly Polarized Magneto-Electric Dipole Antenna: The chapter describes a printed X-band antenna and examines how ground-plane and feed dimensions affect its characteristics.
Chapter 6 Design of a Magneto-Electric Monopole Antenna: This chapter presents a non-planar monopole, its current distribution and equivalent-circuit analysis, followed by measurements and dimensional studies.
Chapter 7 Concluding Remarks: The final chapter brings together the designs and discusses their potential wireless applications.
Keywords
magneto-electric dipole, magneto-electric monopole, wideband antennas, impedance bandwidth, differential feeding, end-fire radiation, circular polarization, ground plane, cavity reflector, antenna gain, radiation pattern, method of moments, IE3D, wireless communications
Frequently Asked Questions
What is this work about?
It examines the design and evaluation of wideband magneto-electric dipole and monopole antennas for wireless communication.
What are the main topics?
The work covers complementary radiators, feeding structures, radiation patterns, polarization, ground-plane modifications and antenna performance.
What is the primary objective?
The objective is to develop antenna designs suited to different wireless applications while addressing bandwidth, gain and radiation characteristics.
What research methods are used?
The research combines literature review, method-of-moments electromagnetic simulation, prototype fabrication, measurements, equivalent-circuit modelling and parametric studies.
What does the main part discuss?
It presents five antenna configurations, explaining their geometry, operation and evaluation through simulations and measurements.
Which keywords characterize the work?
Key terms include magneto-electric dipole, monopole, wideband antenna, impedance bandwidth, differential feed, circular polarization and radiation pattern.
How is the end-fire antenna fed?
The end-fire design uses a Z-shaped feed to excite its electric and magnetic dipole elements.
What is distinctive about the planar antenna?
The planar design combines T-shaped electric dipoles, shorted stubs, an inverted U-shaped feed and a truncated ground plane for circularly polarized X-band operation.
How is the monopole antenna analyzed?
Its analysis includes current distribution, an equivalent circuit and input-impedance calculations, alongside simulation and measurement.
- Quote paper
- Neetu Marwah (Author), 2021, The Perspective of Magneto-Electric Dipole Antennas, Munich, GRIN Verlag, https://www.hausarbeiten.de/document/1139999
