Ultra-wideband arrays

In this chapter, we focus on these modern challenges faced by wideband array designers, and the substantial advancements which have been made over the past 5 years. Initially, we provide a review of UWB array designs to familiarize the reader with the two most common groups of UWB arrays. These are developed with an overview of their basic principles, practical design considerations, and illustrative examples from the literature. Thereafter, we delve into the particular challenges associated with designing these arrays for the emerging applications at millimeter-wave frequencies.