Abstract Frequency Selective Surfaces (FSS) are increasingly being used in telecommunications systems due to the numerous advantages presented by this sort of structure, among them low cost, ease of fabrication, and low profile stand out. This work reports the design, fabrication, and characterization of a multilayer frequency-selective absorber (FSA) for broadband operation. The proposed structure shows an absorption performance (operating in the frequency range between 2 GHz and 6 GHz) within the transmission band. The absorber consists of cascaded frequency selective surfaces, which are composed of both conductive square loops, which reflect incident signals, and resistive ones, which act as an absorbing layer. To verify the absorbing structure performance, full-wave numerical simulations and measurements are presented. The measured results are in good agreement with the numerical ones and show that the design performs absorption above 80% within the range of 2.48 GHz to 6.13 GHz, which verifies the project properties. Besides that, numerical results show that the proposed absorber has a proper response under oblique incidence up to 30°. FSS (FSS cost fabrication out frequencyselective FSA (FSA operation operating band surfaces loops signals layer fullwave full wave 80 248 48 2.4 613 13 6.1 properties 30 30° 8 24 4 2. 61 1 6. 3

Abstract In this paper, we propose a simple technique to analyze absorber/transmitter frequency selective surfaces (FSS). The structure is formed by two FSS, one resistive and one conductive. Both FSS are printed on an FR4 dielectric substrate. The square loop and crossed dipole are the geometries considered in this paper. The technique combines two simple approaches, the equivalent circuit method, and the scattering matrix method. Two prototypes were built for validation purposes. Simulated and measured results are in good agreement.

Abstract This paper presents a microstrip phased array using High Impedance Surface - Electromagnetic Bandgap (HIS-EBG) in order to minimize the effects of mutual coupling among the antenna elements. Each element of the array is fed by a coaxial cable allowing the beam steering by controlling the signal of the input port of each element. This phased array operates at X Band as well as the bandgap of the HIS-EBG structure. Its main applications are satellite communication and broadcasting systems. Results show reductions in the mutual coupling up to 12 dB, and improvements in the return loss and gain.