# Introduction he MSA in 1953 [1] and practical antennas were developed by Munson [2,3] and Howell [4] in the 1970s. The numerous advantages of MSA, such as its low weight, small volume, and ease of fabrication using printed-circuit technology, led to the design of several configurations for various applications [5][6][7][8][9]. With increasing requirements for personal and mobile communications, the demand for smaller and low-profile antennas has brought the MSA to the forefront. An MSA in its simplest form consists of a radiating patch on one side of a dielectric substrate and a ground plane on the other side. The T-shape of microstrip patch antenna as shown in Figure 1. However, other shapes, such as the square, circular, triangular, semicircular, and annular ring shapes etc. In this paper, we present a designing of T-shaped microstrip patch antenna and show the results for return losses operating at different frequencies. The dielectric constant (? r =4.2) of the dielectric substrate and thickness of the substrate h=1.6 mm. # II. # Designing Of T-Shape Microstrip Patch Antenna The Figure 1. Shows the T-shaped microstrip patch antenna. The T-shaped microstrip patch antenna is simpler in construction. The geometry is shown in figure 2. + = + = r r r r f v f W ? ? ? µ (1) Where ? o is the free-space velocity of light. 2 1 12 1 2 1 2 1 ? ? ? ? ? ? ? + ? + + = W h r r reff ? ? ? (2) Where the dimensions of the patch along its length have been extended on each end by a distance ?L, which is a function of the effective dielectric constant ? reff and the width-to-height ratio (W/h), and the normalized extension of the length, is ( ) ( ) ? ? ? ? ? ? + ? ? ? ? ? ? ? + + = ? 8 . 0 258 . 0 264 . 0 3 . 0 412 . 0 h W h W h L reff reff ? ? (3) The actual length of the patch (L) can be determine as The designing of the microstrip patch antenna by the used of IE3D electromagnetic three dimensional simulators and MATLAB programming. The dimensions of the T-shaped microstrip patch antenna parameters as shown in table 1. III. # Analysis of Antenna using FDTD Method The basic FDTD space grid and time-stepping algorithm trace back to a seminal 1966 paper by Kane Yee in IEEE Transactions on Antennas and Propagation (Yee 1966). The descriptor "Finite-difference time domain" and its corresponding "FDTD" acronym were originated by Allen Taflove in a 1980 paper in IEEE Transactions on Electromagnetic Compatibility (Taflove 1980). The FDTD method has been used for the analysis for the probe-fed microstrip patch antennas and can indeed yield very accurate highly result. The FDTD method uses Maxwell's equations which define the propagation of an electromagnetic wave and the relationship between electric and magnetic field, these are E t H × ?? = ? ? µ (5) H J t E × ? = + ? ? ? (6) ? ? = ? ? E (7) 0 = ? ? H (8) By applying appropriate boundary conditions on sources, conductors and mesh walls an approximate solution of these educations can be find over a finite three-dimensional domain. The equation in the i direction gives: Y h ? r W L L 1 L 3 W 1 W 2 T-shape patchL f L reff r ? ? = 2 2 1 0 0 ? µ ? (4) y E Z E t H Z Y x ? ? ? ? ? = ? ? µ (9) The maximum time step that may be used is limited by the stability restriction of the finite difference equations. This is given by 2 1 2 2 2 1 1 1 1 ? ? ? ? ? ? ? + ? + ? ? ? z y x c t (10) Where c is the speed of light (300 000 000 m.s?1) and Î?"x, Î?"y and Î?"z are the dimensions of the unit element. IV. # Results The simulated results of the return loss, VSWR, and Radiation pattern of E and H plane as shown in fig 3 (a) (b) and (c).The return loss is -13.63 dB, VSWR 1.562, and the bandwidth of the antenna is 123 MHz at the 2.5 GHz resonant frequency. The result of the return loss (-16.78 dB) by using MATLAB programming as shown in Figure 4. The results of the T-shape microstrip patch antenna as shown in Table 2 Simulation results using IE3D and MATLAB programming. ![Author: M. Tech. (Student), Department of Computer Science and Engineering, Centre for Development of Advanced Computing, Noida(U.P.) -201301, India. E-mail : amitcdacnoida@gmail.com](image-2.png "") 12![Figure 1 : T-shaped of microstrip antenna The T-shaped microstrip patch antenna has width (w) and length (L). Outer patch strip width is w 1 . The patch is fed at position p0 by a coaxial probe. The dielectric substrate materials are used for fabrication of antenna element. Designing of the T-shaped microstrip patch antenna as shown in Figure 2. The designing of Tshaped microstrip patch antenna the resonant frequency f r 2.5 GHz and the dielectric substrate is used for the design the T-shaped of microstrip patch antenna. The dielectric constant of the substrate is ? r = 4.2 and thickness (h) of the substrate h= 1.6 mm to design the T-shaped microstrip patch antenna.](image-3.png "Figure 1 :Figure 2 :") ![Designing and Analysis of T-Shape Microstrip Antenna for the 4G Systems](image-4.png "E") 334![Figure 3(a)](image-5.png "Figure 3 Figure 3 :Figure 4 :") 1parametersFrequency fr2.5 GHzW37.21W 127.21W 210L28.89L 112L 216.89L 34.89Dielectric constant ? r4.2Thickness of the1.6substrate h 2programmingS.No. ParametersResultsSoftware1Return loss 1 -13.63 dBIE3D2VSWR1.562IE3D3Return loss 2-16.78MATLAB4Bandwidth123MHz Theoretical E ? ? © 2013 Global Journals Inc. (US) EDesigning and Analysis of T-Shape Microstrip Antenna for the 4G Systems EDesigning and Analysis of T-Shape Microstrip Antenna for the 4G Systems * JRJames PSHall Handbook of Microstrip Antennas London Peter Peregrinus Ltd 1989 1 * Antenna theory-Analysis and Design ConstantineBalanis 1997 John Wiley & Sons Ltd Reprinted * Design Small-Size and Wide-Band Tshaped patch Antenna on Ceramic Substrate Cheng-FuYang Chang-YiHsieh Chien-MinCheng IEEE Trans. Antennas Propagation 2007 * Conformal Microstrip Antennas and Microstrip Phased Arrays REMunson IEEE Trans. Antennas Propagation 22 1974 * JQHowell Microstrip Antennas January 1975 * Design of Nonplanar Microstrip Antennas and Transmission Lines KLWong 1999 Wiley New York * Microstrip Microwave Antennas GADeschamps Proc. 3rd USAF Symposium on Antennas 3rd USAF Symposium on Antennas 1953