Experimental demonstration of compact spoof localized surface plasmons.

In recent years, the study of generating and detecting localized surface plasmons (LSPs) has been expanded from the optical regime to microwave regime. In this Letter, the compact spoof LSPs are introduced through both numerical simulations and near-field measurements. It is observed that the compact LSP structure could effectively reduce the resonant frequency with a stronger resonance strength (GdBsm) and a higher Q-factor. Both electric near-field and surface-current distributions are monitored to examine the resonance processes of the LSP particle.