International Journal of Engineering Research and Development e-ISSN: 2278-067X, p-ISSN : 2278-800X, www.ijerd.com Volume 5, Issue 4 (December 2012), PP. 52-56 52 Triple Band Triangular and Exponential Serrated MSP Antennas for S and C Band Applications 1 G.Asa Jyothi, 2 P.Siddaiah, 3 B. Prabhakar Rao, 4 B.T.P.Madhav 1 Associate Professor, Department of ECM, K L University, Guntur DT, AP, India 2 Dean, ANU College of Engineering, ANU, Guntur DT, AP, India 3 Director, Admissions, JNTU Kakinada, AP, India 4 Associate Professor, Department of ECE, K L University, Guntur DT, AP, India Abstract:- Serrated Microstrip Antennas are gaining their importance in the applications of dual and multiband antenna systems. A Serrated cutting edge has many small points of contact with the material being cut. The Serrations are mainly used in the Compact Antenna Test Range (CATR) measurements for the measurement of antenna parameters. In Serrations, by having less contact area than a smooth blade or other edge, the applied force at each point of contact is relatively greater and the points of contact are at a sharper angle to the material being cut. The present paper deals with the performance evaluation of Triangular Serrated Microstrip antenna and combination of Triangular – Exponential serrations. The simulated output parameters like Return loss, gain, input impedance and field distributions along with radiation patterns are presented in the current work. Keywords:- Dual and Multiband, Serrations, CATR, field distributions. I. INTRODUCTION Serrations are common both in nature and in man made objects. In nature, serrations are commonly seen in the cutting edge on the teeth of some species like shark. However, it also appears on non-cutting surfaces, for example on leaf margin or other plant part. The CATR provides a relatively new method of measuring the far field characteristics of Microwave antennas. The Test antenna is illuminated by a collimated beam of energy from a parabolic reflector. The diffractions from the edges of the reflector are minimized by serrating the edges of the reflector [1-5]. The Microstrip antennas are being used in many advanced applications of the communication systems. The aperture of the microstrip patch will be mould similar to the serrated CATR [6-7]. By placing different shapes of serrated apertures on the MSP antenna, giving results for multiband applications. This was recently observed while taking the equally spaced linear serrated edges [8-10]. The present model deals with non-linear triangular serrated aperture based MSP antenna and linear triangle – exponential serrated MSP antenna. The performance evaluation of both the models are simulated using commercial, finite element method based Electromagnetic Simulator, so called Ansoft HFSS. II. EVALUATION OF SERRATED EDGES The Exponential serrations designed at the x-axis boundaries of the MSP antenna are represented as follows in figure 1.2. F (x | ) = t .e (-a 1 p 1 ) + t (1-e (-a 1 x | )) 0 < x | < p 1 = t .e-a 2 (x | -p 1 ) p 1 < x | < p 2 = t. e (-a 3 (p 3 -p 2 )) + t {1-e (-a 3 (x | -p 2 ))} p 2 < x | < p 3 = t. e (-a 4 (x | -p 3 )) p 3 < x | < p 4 = t. e(-a 5 (p 5 -p 4 ))+{1-e(-a 5 (x | -p 4 ))} p 4 < x | < p 5 = t .e(-a 6 (x | -p 5 ) ) p 5 < x | < p 6 = t. e(-a 7 (p 7 -p 6 ))+t {1-e(-a 7 (x | -p 6 ))} p 6 < x | < p 7 = t .e(-a 8 (x | -p 7 )) p 7 < x | < p 8 The Triangular serrations obtained at the y-axis boundaries of the MSP antenna are represented as follows F (y | ) = (t. y) / p 1 0 < y | < p 1 = -t(y-p 2 ) / (p 2 -p 1 ) p 1 < y | < p 2 = t(y-p 2 ) / (p 3 -p 2 ) p 2 < y | < p 3 = -t(y-p 4 ) / (p 4 -p 3 ) p 3 < y | < p 4 = t(y-p 4 ) / (p 5 -p 4 ) p 4 < y | < p 5 = t(y-p 6 ) / (p 6 -p 5 ) p 5 < y | < p 6