Periodic comb reflection frequency selective surface for interference reduction

This paper describes a passive periodic comb reflection frequency selective surface (CR-FSS) which enables deployment of several high capacity Wi-Fi nodes in a small office scenario by reducing potential interference between each. The CR-FSS is designed to reduce transmission between adjacent access points down a corridor by reducing the forward scatter, and redirecting it as backscatter. The surface design comprises a comb structure based on Bragg´s Law, which determines the point where maximum backscatter occurs. By optimising the period of the comb structures we can control the direction of the reflected wave over a predefined range of frequencies. Simulations validate the frequency selectivity of the surface design and show that the peak reduction in forward scatter can be controlled. Results show that peak reductions in forward scatter of at least 8 dB occur between 12 and 15 GHz for the simulated design. The surface reduces forward scatter by at least 6 dB between angles of incidence of 40° to 80°, with a peak reduction of 12.8 dB at 53°.