Eyshika Agarwal et al. Design and Analysis of Rectangular Patch Micro “trip Antenna with Defected Ground Plane for WiMAX applications 30 Proceedings of DIGNATE 2014:: ETEECT 2014 ISBN 978-93-5196-068-3 Design and Analysis of Rectangular Patch Micro Strip Antenna with Defected Ground Plane for WiMAX applications Eyshika Agarwal #1 , Ayushi Shrivastava #2 , Nitin Tripathi #3 , Sumit Srivastava #4 #1,2,3 Student, Dept. of Elec. & Comm., Invertis University Bareilly, U.P., India #4 Asstt. Prof., Dept. of Elec. & Comm., Rohilkhand University Bareilly, U.P., India 1 eyshikaagarwal@yahoo.co.in 2 ayushi9528@gmail.com 3 nitintripathi2810@gmail.com 4 sumitsrivastava@mjpru.ac.in Abstract-In this paper, a simple rectangular microstrip patch antenna with defected ground plane is designed having dimensions of 21 X 26 X 1.5 mm 3 at frequency3.5 GHz approx. used for WiMAX applications, such as wireless broadband connectivity. Various parameters (Reflection Coefficient, Directivity, Bandwidth, Return Loss, VSWR, Radiation Pattern etc.) of micro strip antenna are observed using defected ground. Simulation of the antenna is done byIE3D(14.2 Version) Simulation Software. The main purpose of this paper is to get the good response of micro strip antenna under defected ground structure(DGS) in comparison to non-defected ground structure(NDGS) and to increase its applications. The simulated results give significant improvement in return loss, bandwidth and reduced patch size of antenna. Keywords-Micro strip Patch Antenna (MPA), Defected Ground Structure (DGS), IE3D, WiMAX. I. INTRODUCTION Due to eruptive growth of wireless system high demand for a new wireless applications, it is important to design high bandwidth and low losses antenna to cover most of the frequency range. And this is the reason why Micro strip antenna comes in context. It has various merits such as low volume, compatibility with IC’s, light weight, easy to install and low cost [1]. They are designed to operate in multi-band and dual-band applications either by linear or circular polarization. They are used in different handheld transmission and reception devices. However, the micro strip patch antennas have so many demerits such as narrow bandwidth, and high radiation losses which affects its usage [2,3,4]. This forces many researchers to design such an antenna which will have large bandwidth, low return loss and high directivity. Micro strip antenna contains a dielectric substrate (FR-4) having a fixed value of dielectric constant and thickness. The increase in thickness may increase the losses which is considered as a disadvantage of antenna. Radiating patch (rectangular) is designed on upper side of the substrate. Dimensions of patch changed as per the radiating frequency, since it is inversely proportional to the frequency. Patch is generally made of copper or gold, used as a conducting material which can be converted in any shape [5,6]. Micro strip Antenna is mainly designed in double sided printed circuit board (PCB) and they are also known as embedded antennas. Many methods are used to make the antenna more effective, Defected Ground Structure (DGS) is one of them. This structure may increase the applications of antenna as it works on the major drawbacks of MPA. DGS lesser the surface waves and improves the antenna efficiency [7]. To make the defected ground structure, ground is etched with a rectangular shape slot of 2 X 12 dimensions vertically. This etched portion increases the capacitance and inductance which improves the return losses because when the effective capacitance and inductance of ground plane becomes equal to each other then, resonance condition is satisfied. In this paper, the DGS structure antenna is used for WiMAX applications, because WiMAX used for wireless broadband connectivity across the countries and cities. This is an important aspect for internet connection. WiMAX gateway devices, cellular phones, internet connectivity gives a new name to this world. All this designing of antenna is done by IE3D software [10]. IE3D offers the highest simulation capacities and fastest turnaround times for broadest number of applications. It is an integrated full wave electromagnetic simulation and optimization package for the analysis and designs of 3-D micro strip antennas. It is considered as one of the best software for antenna designing. II. ANTENNA CONFIGURATIONS The substrate in Micro strip antenna plays a significant role in determining the size and bandwidth of antenna. On increasing the value of dielectric constant, size decreases and losses in antenna increases which lowers the