IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 _______________________________________________________________________________________ Volume: 05 Issue: 01 | Jan-2016, Available @ http://www.ijret.org 283 DESIGN AND ANALYSING OF COMPACT MICROSTRIP ANTENNA WITH DEFECTED GROUND STRUCTURE FOR UWB APPLICATION Rahul Sharma 1 , A.N. Mishra 2 1 ECE Department, Krishna Engineering College, Ghaziabad, India 2 ECE Department, Krishna Engineering College, Ghaziabad, India Abstract In this paper a small size microstrip antenna with DGS (Defected ground structure) is designed and analyzed for UWB(Ultra Wide Band) application. This antenna cover the complete frequency range of 3.1 to 10.6 GHz with a very small geometry as compared to a conventional antenna Dielectric substrate use in this antenna is Fr-4. This antenna is designed with a dimension is 36mm × 34 mm on a dielectric substrate Fr-4 whose permittivity ε r =4.4 and height h = 1.6 mm. The result for return losses and radiation patterns is simulated by using HFSS (High Frequency structure simulation) software. The High frequency structure simulator is employed to analyze the planned antenna and simulated results on return loss, The ground element of the proposed antenna is taken in the form of defected ground structure (DGS). Keywords: Microstrip Antenna, UWB, DGS, Wide band, HFSS --------------------------------------------------------------------***---------------------------------------------------------------------- 1. INTRODUCTION Micro strip patch antenna is wide beam width, narrowband antenna. And consists of three major part there is ground, patch, substrate (here used FR-4). There are numerous substrates that can be used for the design of microstrip antennas, and their dielectric constants are usually in the range of 2.2 ≤ ε r ≤ 12 [4][5] [6]. In this paper used Defected Ground Structure technology. Defected Ground Structure is unique technology to reduce the antenna size. A DGS may come in a variety of geometries and sizes, depending upon their mode of application, as well as the frequency of operation [8][9]. The Defected Ground Structure (DGS) technology are various type there is Dumbbell-shaped, Square heads connected with U slots, H-shaped[9], Meander line, U-shaped[9], T-shaped, DGS in T-shaped and rectangular shaped. And Ultra wide band range (UWB) released by Federal Communications Commission (FCC) since 2002. It Covers frequency range 3.1 GHz to 10.3 GHz.[2] [3]. The ultra-wideband (UWB) systems advantages is it is consist high speed data, small size, not expensive, low complexity[1-4,1][10]. This antaean is simulated by HFSS. HFSS is integral equation and method of the moment based Electromagnetic simulator. 2. ANTENNA STRUCTURE AND EQUATION In Fig. 1 and Fig. 2 show geometry of the proposed microstrip patch antenna with DGS on the Fr4 substrate together with its geometrical dimensions. In the table 1 and table 2 also refer the dimension value of microstrip patch antenna. Value of antenna is taken in mm. Also equation 1,2,3,4 are calculate the dimension of the microstrip antenna. . A. Antenna Geometry (a) (b) Fig.1- Microstrip antenna on FR-4 Substrate