This book introduces the design process using HFSS to realize practical antennas. An overview of the commercial software to solve antenna design problems is introduced. Choice of solver for the specific antenna type is also explored in this book. Insights about the applications of HFSS are also presented. Design flow with detailed reasoning for a generic antenna simulation is discussed, which gives a thorough understanding of the simulation settings. A simple antenna is investigated in detail to equip readers with the analytical skills required to solve challenging antenna problems. A software perspective of the antenna parameters and its practical significance is also elaborated in the book. A detailed presentation on transmission lines and its graphical analysis is included. Numerous variants of classic antennas are analyzed in-depth to solidify the reader's design skills in these approaches. An exclusive chapter on fabrication and measurements is included to correlate the simulation results with those of the corresponding experimental results. Tips and tricks to ace simulations in High Frequency Structure Simulator (HFSS) is presented toward the end of the book.