Horn Antennas Loaded with Metamaterial For Satellite band Application Mohamed Lashab, C. Zebiri and F.Benabdelaziz Electronics Department, Skikda University, Algeria. Lashabmoh@yahoo.fr, Zebiri@ymail.fr, Benabdelaziz2003@yahoo.fr Abstract— A Split Ring Resonator (SRR) as Metamaterial has been loaded on pyramidal horn antennas for Ku band or satellite application. The aim of this work is to exhibit the advantage of metamaterial (SRR) use inside horn antenna; this is mainly enhancement of the bandwidth towards lower frequency and improvement of the radiation pattern gain. The horn antenna is feed by a monopole antenna of optimised length. The obtained results from HFSS simulation concerning the constitutive parameters of the (SRR), show that there is a DNG (Double Negative) permeability and permittivity in the frequency of interest. In this work the operating bandwidth of the proposed antenna (notched band) is in the range of 9.80 GHz to 10.30 GHz, and 10.80 GHz to 11.20 GHz as Ku or satellite application. Index Terms— Metamaterial, Horn antennas, Return loss, constitutive parameters, DNG, Satellite. I. INTRODUCTION Metamaterial is well known as artificial material, also known as left hand side, suitable for designing antennas of high absorption. Recently it has been of great interest, both for theoretical development [1,2], and for experimentally works [3,4]. Since ten years ago many research work have been investigated on the effect of dielectric or ferrite object inside the taper of a horn antennas [5, 7]. Here in this paper we are looking at the effect of metamterial (SRR) inside the throat of the horn antennas, just to see the advantage of this application in the satellite band (K u or X band) Many combination of dielectric or ferrite layer have been tested but seems that the metamaterial is more interesting [8]. Pyramidal Horn antennas loaded with metamaterial [9], have desirable properties such as increased directivity, reduced side lobe level, wide bandwidth, and ease of fabrication [10,12]. These properties are particularly attractive for applications such as ultra-wideband (UWB) ground penetrating radars (GPR) [13]. However, the characterization of such antennas with increasingly complex designs using analytical techniques is often not possible. On the other hand, a numerical model can provide a virtual test bench to explore different design possibilities before any costly prototyping. Although many numerical techniques can be used to model and study the characteristics of such antennas, the moment method is well known to provide good accuracy [14,15]. This paper deals firstly with the design of unit cell of PCB, as metamaterial operating in the range of 8.20 GHz to 9.50GHz, and from 11.20 GHz to 14.0 GHz as a notched band, the unit cell is designed by HFSS and the obtained S-parameters are used for the extraction of the constitutive parameters of the unit cell. The PCB is inserted at the top of the horn antennas throat, the obtained return loss by simulation show that resonant frequency of the horn antenna is shifted towards the unit cell. II. METAMATERIAL INSPIRATION A. Theoretical concept The metamaterial is an artificial material, the extraction of the constitutive parameters needs experimental tests or analytical models. Drude–Lorentz model [16, 17], known as dispersion model is very accurate, in which the magnetic permeability and electric permittivity are extracted analytically. Another well-developed characterization method of metamaterials is the standard retrieval procedure [18,19]. The assigned effective refractive index (n) and relative impedance (z) values of the metamaterial PCB can be extracted from the S-parameters assuming that the unit cell test is symmetric with respect to the (x–y) plane, which means S11 = S22 and S21 = S12. The relative impedance can be given with respect to the S- parameters using the following formulas: ( ) ( ) 2 21 2 11 2 21 2 11 1 1 S S S S Z − − − + ± = (1) And, d k Z Z S S j n 0 11 21 1 1 1 1 ln .                   + − − − = (2) Where o k the free space propagation and (d) is the thickness of the unit cell, here d is chosen to be 5 mm. The constitutive parameters can be derived from the above equation as: Z n eff / = µ (3) And, Z n eff . = ε (4) INTERNATIONAL JOURNAL OF COMMUNICATIONS DOI: 10.46300/9107.2020.14.3 Volume 14, 2020 ISSN: 1998-4480 12