An antenna is of substantial importance for a communication system as the design of
an air interface is mainly reliant on the antenna design. With the significant wireless
evolution from 1G to 6G, technologies and network capacities are also evolving to
fulfill the promptly growing customer demands. These continually increasing demands
have gone concurrently with extensive technological accomplishments of the antenna
design community. This chapter discusses the sub-6 GHz and millimeter-wave (mm-wave)
fifth-generation (5G) antennas, including antenna arrays, multiple-input, multiple-output
(MIMO) technology, beam-steering techniques, metasurfaces, and other techniques to
achieve the current and impending fast connectivity. Moreover, the design specifications,
research directions, various technologies expected to be involved, and challenges
in the design, fabrication, and measurement of the sixth-generation (6G) antennas
at the THz band have also been presented. In addition, antenna-in-package (AiP) and
antenna-on-chip (AoC) technologies with proper technology solutions have also been
discussed.
