Port Isolation and Array Spacing of a 5 × 5 Rotman Lens Frequency Decomposer

Dynamic frequency allocation is a critical aspect for the fifth-generation (5G) wireless technology. With strong movement toward millimeter-wave frequencies, analog decomposition of frequency sub-bands is of great importance. In this article, we deeply investigate some of the characteristics of a Rotman lens frequency decomposer in terms of bandwidth, channel isolation, and physical size. This study shows that a compromise between flexibility, optimality, and physical size is needed for Rotman lens frequency decomposer, which in turn is motivated (and weighted) by the required application.