Dedicated to a new class of wideband antenna, significantly developed over the past two decades, this book is the ultimate reference on magnetoelectric dipole antennas. The author is world-renowned for his pioneering work on antennas and has continuously developed the magnetoelectric dipole antenna since 2006. With contributions from the author and his students as well as results from research groups worldwide, the development of this novel antenna is fully captured. The theory and design are presented step-by-step, using simple technical explanations, making the contents accessible to readers without specialized training in antenna designs. Including the various applications of the antenna such as communications, global positioning, sensing, radar, medical imaging, and IoT, this book endeavors to demonstrate the versatility and interdisciplinarity of the antennas.

Major techniques for enhancing the bandwidth of magnetoelectric (ME) dipoles available in the literature are reviewed and discussed. Designs with single-input port and differential input ports are reported. Hopefully, it can help the readers to appreciate the beauty of these interesting designs and inspire innovative designs for future applications.

As the textbook is concerned with the application of immersed boundary methods for complex flow simulations, some general preliminary considerations are necessary in order to make the book self-consistent.

Basic concepts about fluids, their governing equations and the fundamentals relating to numerical integration are introduced and discussed.

Using a simple numerical example of the flow around a square cylinder, the relation between spatial numerical resolution and smallest flow scale is introduced and explained in connection with the successive requirements of immersed boundary methods.

A final discussion of the concepts of verification and validation of a numerical model closes the chapter.

In this chapter, techniques for size reduction of the magnetoelectric dipole available in the literature are reviewed. The relative advantages of employing the folded patch technique, dielectric-loaded method, and the metamaterial-loaded approach are compared. Designs with single-input port and differential input ports are also reviewed. Hopefully, possible new techniques will be achieved by readers after reviewing all these interesting designs.

When the flow and immersed object dynamics are two-way coupled, the problem is a fluid-structure interaction and additional changes are necessary to implement immersed boundary methods. Depending on the coupling between flow and structure solvers (loose or strong), the nature of the structure (rigid or deformable body) and the specific solution algorithms, several possibilities are available and this chapter aims at providing insights to guide the choice.

The performance of the basic linearly polarized magnetoelectric dipole is reviewed in detail to prepare the readers to appreciate other sophisticated designs in the chapters to follow. A new equivalent circuit of the antenna is given, which is different from the previous one proposed in the literature. The current density distributions on the antenna surfaces are provided to help understand the operating principle of the magnetoelectric antenna. The effect of ground plane size and sidewall height on the radiation patterns is given. Finally, a design guideline is suggested.

Substantial amount of work on the development of ME dipoles has been published by the originator’s group and other researchers and scholars over the past decade. It is now the appropriate time to review those findings and put those useful designs into appropriate perspectives. After providing the necessary background in understanding the importance of the ME dipoles in this introductory chapter, the detailed design guideline and performance of various ME dipoles with different characteristics will be presented and discussed in the chapters to follow.

This chapter is devoted to numerical examples and applications intended as tutorials for the interested reader. The possibility to download and use a computer code together with the book is given, and some of the described examples can be replicated using the provided code. The examples are of increasing complexity and they range from simple two-dimensional flows up to complex three-dimensional problems with fluid-structure interaction.

A detailed description of the computer code is also included in order to allow the readers to quickly get acquainted with the method and allow them to modify it according to their needs.

This chapter begins with a motivation to use computational models in scientific and technical applications. An overview of the advantages and drawbacks of numerical simulations with respect to laboratory experiments is given and advancements in various fields are discussed.

After this general introduction, a historical overview of the subject is presented and the present state of the art is discussed. In particular, it is shown that immersed boundary methods are being used in all fields of computational science and the number of scientific publications per year has been increasing with a constant acceleration over the past two decades: This has resulted in an exploding research field in which a reference textbook is still missing.

Finally, the objective of the book and the plan of the various chapters is given.

Various feeding techniques and antenna structures for achieving dual-polarized and circularly polarized ME dipoles will be reviewed. Since some circularly polarized ME dipoles can be developed from dual-polarized ME dipoles, these two classes of ME dipoles are considered and reviewed together here.

The development of linearly polarized magnetoelectric (ME) dipoles operated at lower microwave frequencies is reviewed. Magnetoelectric dipoles can be fabricated at low costs, as they are purely made of metal plates at a few GHz range. Designs with modified L-shaped probe feeds for various purposes are first presented. Magnetoelectric dipoles with modified dipole shapes and feeds for enabling the antennas to be d.c. grounded are summarized. The aperture coupling technique was widely applied for the designs of microstrip antennas. Magnetoelectric dipoles with aperture-coupled feeds were also proposed in the literature. Their characteristics are presented. Differentially fed ME dipoles are also reviewed. The performance of ME dipoles for MIMO systems is discussed, which is of topical interest for 5G applications. Some recent applications of linearly polarized ME dipoles in different array environments are also presented.

As IBMs have gained popularity, their use has expanded to multiphysics problems in which the Navier-Stokes equations are only one among many other possibilities. In this chapter, a list of advanced applications is described in which IBMs are used to solve heat transfer, phase change and chemical reaction problems. These examples are intended as suggestions to extend the application of immersed boundary methods to complex physics problems.

The various forcing strategies to be implemented in the governing equations are described in this chapter. Two big categories are first introduced, namely continuous forcing and discrete forcing methods. The various techniques are then detailed and the steps needed to implement them into an existing flow solver are described.

As any immersed boundary method has to be coupled with a solution algorithm for the governing equations, pseudo-compressibility and fractional-step methods are described in detail and some issues related to their combination with IBMs illustrated.