A Metamaterial Series-Fed Linear Dipole Array with Reduced Beam Squinting

Abstract

The recent implementation of negative-refractive-index (NRI) media by periodically loading host transmission-lines (TL) with lumped-element series capacitors and shunt inductors has led to the development of numerous practical devices based on NRI-TL metamaterials (MTM). The MTM feed networks were shown to be useful in series-fed linear arrays for effectively replacing one-wavelength long conventional meandered transmission lines, thus achieving compact, broadside radiators, whose beam squints less with frequency. In addition, the MTM feed networks can be used to create linear arrays whose main beam remains virtually fixed at a negative angle from broadside as the frequency is varied. Alternatively, a single CPS MTM feedline operating inside the radiation cone can be used to implement a leaky-wave antenna (LWA), which can be recognized as the dual of the CPW line to create a backward LWA