International Journal of Electrical and Computing Engineering Vol. 1, Issue. 1, July – 2014 ISSN (Online): 2349-8218 13 DESIGN OF RECTANGULAR PATCH ANTENNA ARRAY USING ADVANCED DESIGN METHODOLOGY 1 Abishek S, 2 Kaushik Ram S Department of Electronics and Communication, PSNA College of Engineering and Technology, Dindigul, INDIA Abstract Array antennas are used extensively in remote sensing applications, where a highly directive beam is needed to scan a particular area of interest on the surface of the earth. The study focuses on the design of two different microstrip patch antenna arrays to be used in environmental sensing applications in the ISM frequency bands. Arrays of microstrip patches are easily printed on substrates using photolithography techniques and can be mass produced at cheap costs. In this project we have implemented two types of array model using rectangular patch. Specifically, 1X2 and 2X2. This study includes design of feedback network, impedance matching, and return loss calculation. The substrate used is FR4 with dielectric constant of 4.6 and thickness about 1.6mm. The feed network is designed and optimized using ADS 2013 and then integrated with the array. Keywords: Feedback network, Quarter wave Transformer, Radiation Pattern, Return loss. 1. Introduction A microstrip or patch antenna is a low- profile antenna that has a number of advantages over other antenna. It is lightweight, inexpensive, and easy to integrate with accompanying electronics. There are different kind of shapes to construct a single patch antenna. Among them, the shape which adopt the needs can be separable. We choose rectangular patch model. In order to build an array structure, single element is designed with at most care. The application software Advanced Design system has sufficient required simulation techniques to check the antenna parameters. The same result can be compared with the testing equipment, vector network analyzer of Agilent. 2. Single element design issues A microstrip antenna element can be used alone or in combination with other like elements as part of an array. In either case, the designer should have a step-by-step element design procedure. Usually, the overall goal of a design is to achieve specific performance at a stipulated operating frequency. If a microstrip antenna configuration can achieve these overall goals, then the first decision is to select suitable antenna geometry. 3. Single patch dimension Selecting an appropriate substrate of thickness (h) and dielectric constant (εr) for the design of the patch antenna. In present case, we shall use following Dielectric for design: Height: 1.6 mm. Metal Thickness: 1.4 mil (Copper i.e. 35um), Er: 4.6, TanD: 0.001, Conductivity: 5.8E7 S/m. Calculating the physical parameters of the patch antenna as shown in the geometry in Figure 1 using the given formula. Figure 1. Geometry of the Square patch antenna The width and length of the radiation surface is given by, W=L=(c/ (2f√εr)) = 29.2mm. Where, velocity of light, c = 3*10^8 m/s, frequency f =2.4 GHz, relative permittivity, εr = 4.6. The depth of the feed line in to the patch is given by, H = 0.822*L/2 = 12mm. Other dimensions are, Y =W/5 = 5.8mm, X = Z = 2W/5 = 11.7mm 3.1. Antenna simulation Connect a pin at the feed point of the antenna at the required point and go to the EM setup window and click on Substrate then, click on New to accept the 25 mil Alumina template.