An antenna is the interface between the radio waves propagating through space and the electric currents flowing in metal conductors. It is utilized in conjunction with a transmitter or receiver. It can be built to transmit and receive radio waves preferentially in one direction or equally in all horizontal directions. Antennas are necessary for wireless communication systems to function properly at both the transmitter and receiver ends. The rapid development of wireless communication systems has in turn led to the development of innovative antenna technologies such as meta-material antennas, diversity antennas, smart antennas, and various software-defined antenna systems that are making their way onto the market to support modern wireless communication. Smart antenna is an antenna array with digital signal processing algorithms, which identify spatial signatures, which in turn are used by the smart antenna to calculate beamforming vectors that are used to track and locate the antenna beam on a mobile or target. This book aims to shed light on the concept of smart antennas and wave propagation for wireless communication. It also elucidates new techniques and their applications. This book aims to equip students and experts with the advanced topics and upcoming concepts in this area.