Textbook in PDF format The text begins by covering the fundamental concepts, and new advances in the field of antenna theory, antenna hardware, and propagation. It further explains the designing of metamaterials microstrip patch antennas for medical applications, photonic crystals of millimeter wave signals for 5G communications, dual-band miniaturized circular antennas for wireless networks, and ultra-thin compact flexible antennas for wearable applications. This book: Presents the design and development of S-shaped and T-shaped microstrip path antennas for industrial applications. Highlights the use of W-shaped and metamaterials microstrip patch antennas for medical applications. Covers photonic crystals of millimeter wave signals for 5G communications. Showcases the importance of compact and wideband slot antenna for wireless communications. Illustrates the design of an ultra-thin compact flexible antenna for wearable applications. It is primarily written for senior undergraduates, graduate students, and academic researchers in the fields including electrical engineering, electronics, and communications engineering, antenna design, and microwave engineering