Three-Dimensional Bandstop Frequency-Selective Structures Based on Gielis-Shaped Loop Resonator

In this paper, a three-dimensional bandstop frequency-selective structure (FSS) based on Gielis-shaped loop resonator is proposed. A Gielis shape profile for the full and half loop resonator provides a reduction in operating frequency by around 10% compared to a circular profile for a fixed unit cell size. S parameters of an equivalent circuit model for the half Gielis loop unit cell is also discussed.