This book focuses on recent advances in the field of planar antenna design and their applications in various fields of research including space communication, mobile communication, wireless communication, and wearable applications. Planar antennas are also used in medical applications including microwave imaging, medical implants, hyperthermia treatments, and wireless wellness monitoring. However, most of these applications still use bulky antenna systems which hamper their efficiency and applicability despite high application potential. The primary objective of recent antenna research is the reduction in size and complexity. Students, scholars and researchers are used to doing mathematical modelling and pattern measurements in simulated environments only. Our aim is to show academic and industry researchers as well as advanced students and lecturers in electronics, electrical and instrumentation engineering how to do measurements in real-world environments. This book will present planar antenna design concepts, methods, and techniques to enhance performance parameters, as well as applications for IoTs and device-to-device communication. We will provide the latest techniques used for the design of antennas in terms of their structures, defected ground, MIMO, and fractal design. This book will also address the specific steps to resolve issues in designing antennas and how to design conformal and miniaturized antenna structures for various applications.