Book 819

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.


Book 859

This book presents the design of different switching and resonant devices using the present state-of-the-art radio frequency (RF) micromachining (MEMS) technology. Different topologies of MEMS switches have been discussed considering optimum performances over microwave to millimeter wave frequency range. Wide varieties of micromachined switching networks starting from single-pole-double-throw (SPDT) to single-pole-fourteen-throw (SP14T) are discussed utilizing vertical and lateral actuation movements of the switch. Different transduction mechanisms of micromachined resonators are highlighted that includes capacitive, piezoelectric, and piezoresistive types. The book provides major design guidelines for the development of MEMS-based digital phase shifters, tunable filters, and antennas with extensive measurement data. Apart from the radio frequency (RF) requirements, an extensive guideline is given for the improvement of the reliability of micromachined switches and digital phase shifters where multiple switches are operating simultaneously. It takes multiple iterations and extensive characterizations to conclude with a reliable MEMS digital phase shifter, and these aspects are given one of the prime attentions in this book. Detailed performance analysis of metamaterial inspired MEMS switches is then discussed for application in millimeter wave frequency bands up to about 170 GHz. The book concludes with future research activities of RF MEMS technology and its potential in space, defense, sensors, and biomedical applications.