With the massive growth of wireless data in mobile broadband communications, millimeter-wave (mm-wave) communication is an alternative enabling technique for fifth generation (5G) wireless communication systems. More importantly, mm-wave offers large frequency spectrum bands ranging from 30GHz to 300GHz that can be utilized to provide very high capacity (i.e., multigigabits per-second data rates). Moreover, because of the small wavelength at mm-wave frequencies, we can exploit large antenna elements in a small physical area, meaning beamforming schemes are feasible. Nevertheless, high directional antennas should be used due to overcoming the severe path loss and absorption in mm-wave frequencies. Further, the antennas should be steerable in angle and range directions to support point-to-point (multipoint) communications. So far, mm-wave communication has utilized phased-array antennas arrangement which is solely angle dependent. This review paper presents recent array technology, namely, frequency modulated frequency diverse array (FDA) for mm-wave communication applications with an emphasis on beamforming. In FDA, small frequency increment is added across the elements. In doing so, an array beam is generated which is angle-range-time dependent without the need of phase shifters. This feature has several promising potentials in mm-wave communications. In this review, the object is to bring to the fore this advance FDA technology to mm-wave communications community to call for more investigations. We review FDA research progress up to date and highlight the potential applications in mm-wave communications.
A Tutorial on Optical Feeding of Millimeter-Wave Phased Array Antennas for Communication Applications
