Design of an FP/EBG Antenna with Metamaterial PRS Saber DAKHLI 1,2 , Kourosh MAHDJOUBI 2 , Jean-Marie FLOC’H 3 , Hatem RMILI 1,4 and Habib ZANGAR 1 . 1 Sys’COM, ENIT, University of Tunis El Manar, BP 37, Tunis le Belvédère 1002 Tunis, Tunisia. 2 IETR, University of Rennes 1, Campus Beaulieu - bât.11D 263 ave. du Général Leclerc CS 74205, 35042 Rennes Cedex, France. kouroch.mahdjoubi@univ-rennes1.fr 3 IETR, INSA Rennes, 20 avenue buttes des coësmes, 35043, Rennes, France. jeans-marie.floch@insa-rennes.fr 4 ISSAT Mahdia, University of Monastir, 5111, Sidi Messaoud, Mahdia, Tunisia. hatem.rmili@issatm.rnu.tn Abstract—FP/EBG antennas have received intensive attention and large investigations during the last decade. The development of such structure opened the field for real industrial applications in the microwave domain, especially for the antenna design. In this paper we present an FP/EBG antenna operating around 2GHz. The structure consists of a Fabry-Perot Cavity composed of a ground plane, an air cavity and a Partially Reflecting Surface (PRS) made of SRR cells (Slot Ring Resonator). The simulation results show a directivity enhancement of about 4 dB. This structure can be used as directive antenna in communication systems. Index Terms—Metamaterial, Fabry-Perot cavities (FP), EBG structures, Split Ring Resonators (SRR), Microstrip Antenna. I. INTRODUCTION EBG (Electromagnetic Band Gap) structures have the ability to improve antenna performances such as directivity. FP/EBG antenna (fig. 1) is composed of a ground plane which reduces the back radiation, a primary source and a Fabry-Perot Cavity which is highly frequency selective and is used as frequency filter in optics and many other domains. Here, we use it as an angular or spatial selective component which allows to send the electromagnetic wave in a privileged direction. Figure 1. FP/EBG antenna. This paper presents the design of an FP/EBG antenna operating around 2 GHz in order to enhance the directivity of a microstrip antenna. [1-2-3]. In the following section, we will present the expressions that allow to design the antenna and to compute its geometrical parameters and theoretical performances (bandwidth, beamwidth and directivity). II. THEORETICAL EXPRESSIONS OF IDEAL FP ANTENNA According to [4], the cavity thickness and the antenna performances depend on the working frequency f 0 and the reflection coefficient of the cavity PRS at this frequency: Cavity thickness : (1) Quality factor : (2) Fractional bandwidth : (3) Half power beamwidth : (4) Where: n : Order of the cavity mode. f 0 : Cavity resonance frequency. c : Velocity of the light in the free space. r, α : Magnitude and phase of S 11 . θ E : Half power beamwidth in E plan. θ H : Half power beamwidth in H plan. The directivity of Fabry-Perot Antenna can be deduced from the following expression [5]: (5) In the next section, the practical design of the FP/EBG antenna and the simulation results will be presented. The value of the antenna directivity will be compared to that of the expression (4). d Ground plane Patch antenna Metamaterial PRS