Modern microwave communication systems generally employ filtering subsystems composed of narrowband filters suitably interconnected, whose purpose is the separation (or combination) of several RF signals allocated in different segments of the frequency spectrum (channels). Such subsystems are generally referred to as “Multiplexers.” Actually, several classes of multiplexers exist, which may differ, even noticeably, in overall topology. These classes can be grouped in two very general families: manifold-coupled multiplexers and star-junction multiplexers. In a past issue of IEEE Microwave Magazine, an overview of the design techniques for the former family was given, so this article will focus on the star-junction multiplexers.