This book delves deeply into the substrate integrated suspended line antenna technologies and evaluates its potential to replace conventional three-dimensional (3D) metal-based antennas. Over the years, studies on substrate integrated suspended line antennas have captivated engineers and scientists from the antennas and related engineering fields, all aiming to achieve low-cost and low-loss characteristics. The book establishes a fundamental framework for this topic, while emphasizing the importance of substrate integrated suspended line antennas in the wireless communication and radar...