A thin and broadband absorber using double-square loops

This letter presents a design of thin and broadband absorbers using a two-dimensional (2-D) periodic array of double-square loops printed on a dielectric substrate. Lumped resistors are inserted into the four sides of the loops to absorb the incident electromagnetic wave. Simulated and measured results for the radar cross-section (RCS) of a finite 2-D array of double-square loops are in good agreement and both show that the novel absorber can reduce a conducting plate's RCS greatly over a wide frequency range.