IOSR Journal of Electronics and Communication Engineering (IOSR-JECE) e-ISSN: 2278-2834,p- ISSN: 2278-8735.Volume 9, Issue 4, Ver. V (Jul - Aug. 2014), PP 29-33 www.iosrjournals.org www.iosrjournals.org 29 | Page Bandwidth and Gain improvement by using suspended Fractal MSA at 2.4GHZ Prajakta B.Jadhav 1 , Prof.Mrs.M.M.Pawar 2 1 (SVERI college of Engineering, Pandharpur, India) 2 (SVERI college of Engineering, Pandharpur, India) Abstract: The paper present design of microstrip patch antenna at 2.4 GHz. Further by introducing fractal concept to the star-shaped microstrip antenna Koch curve antenna is designed. The Koch island fractal patch antenna is introduced in order to reduce the antenna size. By space-filling property of fractal geometry, this antenna reveals lower resonant frequency. Based on experimental result, it is found that as iteration and iteration factor increases, the resonant frequency of this patch antenna decreases. Broad band operation with size reduction is obtained. To improve efficiency and bandwidth suspended configuration is used. A comparison of fractal antenna with conventional microstrip patch antenna is made regarding the bandwidth, return loss, VSWR, and gain. The antenna is simulated by the HFSS software.(High frequency structure simulator). Keywords: Bandwidth enhancement, Fractal geometry, HFSS, Microstrip patch antenna, Koch curve. I. Introduction The increasing range of wireless telecommunication services and related applications is driving the attention to the design of multifrequency (multiservice) and small antennas. Operators are looking for systems that can perform over several frequency bands or are reconfigurable as the demands on the system changes. Some applications require the antenna to be as miniaturized as possible as can be done [1]. Antenna is a transducer designed to transmit or receive electromagnetic waves. Microstrip antennas have several advantages over conventional microwave antenna and therefore are widely used in many practical applications [3].Microstrip antennas have low profile, low cost, light weight and conveniently to be integrated with RF devices. The size of the micros trip antennas becomes too large to be manageable. Reduction of antenna size becomes extremely important in wireless communications and hence it is desired to bring down the size of antenna while achieving the same performance of the large size antenna. Fractal geometry plays a prominent role for these requirements. Fractals have non-integral dimensions and their space filling capability could be used for miniaturizing antenna size. To overcome microstrip antenna’s limitation of narrow bandwidth by generating more than one resonant frequency many techniques have been used in the past e.g. different shaped slots, multilayer, stack, two folded parts to the main radiating patch and use of air gap have been proposed and investigated. In the design presented in this paper use of air gap i.e. Suspended technique is used. II. Fractal Geometry Antenna Fractal was first defined by Benoit Mandelbrot in 1975 as a way of classifying structures whose dimensions were not whole numbers.[4] A fractal is a rough or fragmented geometric shape that can be subdivided in parts, each of which is (at least approximately) a reduced-size copy of the whole. Fractals are generally self-similar and independent of scale. There are many mathematical structures that are fractals; e.g. Sierpinski’s gasket, Cantor’s comb, von Koch’s snowflake Fractals also describe many real -world objects, such as clouds, mountains, turbulence, and coastlines that do not correspond to simple geometric shapes. Fractal geometry is a very good solution to reduce the size of antenna. Fractal shaped antennas show some interesting features which results from their geometrical properties. The unique features of fractals such as self-similarity and space filling properties enable the realization of antennas with interesting characteristics such as multi-band operation and miniaturization. In this paper we used Koch’s snowflake fractal antenna 2.1 Properties of Koch antenna The Koch curve has an infinite length because each iteration creates four times as many line segments as in the previous iteration, with the length of each one being one-third the length of the segments in the previous stage. Hence the total length of the curve increases by one third with each iteration and the length of the curve after n iterations will be n (4/3) times the original triangle perimeter, which is unbounded as n tends to infinity. The fractal dimension of the Koch curve is log 4/log 3 ≈ 1.26186. This is greater than the dimension of a line but less than Peano's curve. The Koch curve is continuous everywhere but differentiable nowhere. Different iteration stages of triangular Koch curve is shown in figure 1.