Enhancing wireless on-chip links: Theoretical insights into metal placement in hybrid plasmonic waveguide-fed nanoantennas

Abstract

This study marks a pioneering exploration of how metal placement and the number of metal layers influence the design of hybrid plasmonic waveguide (HPW)-fed nanoantennas, both theoretically and numerically, laying a cornerstone for the development of on-chip wireless links. Emphasizing the creation of a horizontal radiation pattern, the use of dielectric and HPW-based directors has been investigated, examining their effects on radiation direction through identical and opposing configurations. Utilizing genetic algorithms to theoretically solve the complex dispersion equation, key optical properties including propagation length, confinement factor, figure of merit, and effective refractive index have been studied. These properties are essential for evaluating performance across dielectric and metal cap structures, as well as metal-insulator-metal HPW designs, accommodating both long-range (LR) and short-range (SR) transverse magnetic (TM) modes. Furthermore, for the first time, the proposed multi-layer HPW-fed nanoantenna achieves high gains of 10.4 and 8.79 dB for LR and SR modes, respectively, with radiation efficiencies of 0.084 and 0.45 dB. This comprehensive analysis, including a point-to-point wireless link validation using novel topologies, sets a new benchmark for optimizing on-chip communication systems.