Preface

Electromagnetic compatibility (EMC) and electromagnetic interference (EMI) are of interest in almost all aspects of modern daily life. The increased use of and dependence on wireless communication, remote control of critical devices, and machine-to-machine communications make the world more connected and thus more vulnerable to interference and attacks. Therefore, new applications require different treatments and materials that suit their respective environments. For example, flexible and smart reconfigurable material could be of use in biomedical applications. In avionic applications, lightweight, aerodynamic material is of interest. This book addresses recent developments in EMC and EMI in medicine and health care, automotive and avionic industries, the Internet of Things (IoT), industry, and mobile communication. It also presents and examines efficient design tools and testing methods. The book consists of five sections containing fifteen chapters.

The first section covers the electromagnetic spectrum of corona discharge (CD), which concentrates its energy at a very narrow signal below 70 MHz to a level that does not affect radio communication systems. Also addressed are clinical issues and EMC requirements for implantable medical devices such as cardiac pacemakers and vagus nerve stimulators. A life cycle assessment of flexible electromagnetic shields assesses flexible EM shields of fabrics with inserted conductive yarns with and without magnetron plasma coating. Results show that plasma-coated fabric has a substantial impact on the environment. In addition, the section discusses the design, construction, and validation of a high-performance open-area test site (OATS) based on long experience that helps calibrate laboratories and write EMC standards.

The second section analyzes the possibility of cost and space reduction for EMC systems based on multiprobe nearfield measurement systems in combination with OTA (over the air measurements), reference-less systems, spherical nearfield transformation, phase reconstruction, modal filtering, source reconstruction, and software-defined radio receivers. A chapter on sources reconstruction using electromagnetic time reversal (EMTR) identifies the transient disturbance sources in power electronics. This is followed by a study about the characterization of the electromagnetic nearfield radiated emissions using a time-domain analysis to provide an equivalent model consisting of a set of electromagnetic dipole parameters.

The third section discusses analysis and design of absorbers for EMC applications. It introduces analysis and modeling of ferrite-based absorbers for low-frequency applications (below 1 GHz). Different kinds of pyramidal absorbers are presented. Analytical and numerical approaches for predicting their performance and the combination of the ferrite tile and pyramidal dielectric absorbers, including the influence of carbon loading and the use of a matching layer on their performance, are also discussed. This section introduces graphene material in addition to the millimeter-wave application using metamaterial. Artificial surfaces and media for EMC and EMI shielding are discussed for recent advances in lightweight, lowprofile electromagnetic absorbing media, such as metamaterials, metasurfaces, and nanomaterial-based solutions, which may suppress unwanted RF and microwave noises.

The fourth section focuses on EMI issues. EMI pre-compliance measurements reveal sources of interference focusing on the EMC of a prototype of electrical equipment such as LED boards and audio equipment. Electromagnetic emissions due to power converters and methods to measure and reduce the noise fields are presented through simulations and computations. Engineers and researchers working in the development of electrical equipment and the general public interested in EMC issues will find this information helpful.

Finally, the book presents several computational methods on different aspects of EMC. It introduces the Traveling Current Source (TCS) model fundamentals and current reflections at the ground and the upper end of the return stroke channel. It also includes a generic model of the radiation from rectangular film capacitors as a power electronics component, which are sources of electromagnetic radiation. An efficient simulation approach based on hybrid time and frequency-domain algorithms is presented. The computational complexity of the proposed algorithm is analyzed, demonstrating the effectiveness and efficiency of the proposed approach of modeling grounding systems for application in EMC to illustrate the impact of nearby grounding grids. A two-dimensional finite element method of electromagnetic wave propagation through the soil is also formulated. In addition, the boundary value problem is employed to solve the Helmholtz time-harmonic electromagnetic model.

> **Ahmed Kishk** Department of Electrical and Computer Engineering, Concordia University, Montreal, Canada

Section 1
