Book excerpt: This book presents state-of-the-art millimetre wave antennas for next generation 5G communications. The propagation losses associated with the millimetre waves and the signal blockage due to the objects present between transmitter and receiver require novel antenna topologies to address these issues. Various aspects of antenna design related to millimetre wave 5G communication including 28-GHz channel characteristics, mmWave antenna requirements, antenna design strategies for 28 GHz, MIMO/multibeam antennas, and mmWave lens antennas are highlighted. Apart from the general antenna requirements and study related to the 28 GHz frequency band, various new metamaterial-based antennas employing uniaxial or biaxial anisotropic media that enhance the antenna radiation performance are covered in detail. In addition, various new antenna systems such as wide-scan antenna arrays, dual-polarized antennas, and dual-beam/multibeam antennas are covered in this book. The book concludes with the glimpses of the millimetre wave lens antennas and the design of very thin planar metamaterial lens for 5G massive MIMO applications.