Theory of Electromagnetic Radiation in Nonlocal Metamaterials — Part II: Applications

We deploy the general momentum space theory developed in Part I in order to explore nonlocal radiating systems utilizing isotropic spatially-dispersive metamaterials. The frequencydependent angular radiation power density is derived for both transverse and longitudinal external sources, providing detailed expressions for some special but important cases like time-harmonicand rectangular-pulse-excited small dipoles embedded into such isotropic metamaterial domains. The fundamental properties of dispersion and radiation functions for some of these domains are developed in examples illustrating the features in nonlocal radiation phenomena, including differences in bandwidth and directivity performance, novel virtual array effects, and others. In particular, we show that by a proper combination of transverse and longitudinal modes, it is possible to attain perfect isotropic radiators in domains excited by small sinusoidal dipoles. The directivity of a nonlocal small antenna is also shown to increase by possibly four times its value in conventional local domains if certain design conditions are met. © 2020