Microstrip Patch Antenna for Wireless LAN Abstract—This paper presents design, simulation and fabrication of microstrip patch antennas for WLAN applications. Microstrip patch antenna for WLAN frequency (2.4GHz) is designed and simulated for microstrip line and coaxial feed. The various feeding techniques used are microstrip line feed, inset fed, coaxial feed, aperture coupled feed, and proximity coupled feed. We have chosen microstrip line feed and co-axial feed due to the advantage that it can be easily fabricated. The simulation of microstrip antenna is carried out using ADS2009. The return loss, beamwidth and gain for microstrip line feed -12.5dB, 110o and 6dB respectively. The return loss, beamwidth and gain for co- axial fed patch antenna are -29dB, 150o and 4dB respectively. Both the antennas were fabricated using FR4 of dielectric constant 4.6 and thickness 1.6mm. The co-axial feed antenna resonated at 2.4GHz and Microstrip line fed antenna resonated at 2.404GHz. Keywords—Microstrip patch antenna, Rectangular patch, Feeding techniques and WLAN. I. INTRODUCTION In the last few years the wireless local area network (WLAN) has been used in a variety of applications for which new and more restricti ve requirements in the design of the receiving antenna have been introduced. In particular, for high precision WLAN applications, WLAN-based spacecraft attitude determination, a receiving antenna with superior rejection to multipath signals is required[1-5]. Multipath arises when the WLAN transmitted signal takes different paths to the receiving antenna and, being the signals from these paths added with different phases this results in a significant amplitude and phase distortion. A Wireless LAN is ideal for certain work environments and can boost work efficiency levels in most cases. Here's what you'll require to go wireless. Cabling is the least expensive building block of your network, yet it is highly significant for performance and reliability. Bad cabling can result in frequent network breakdowns. Sometimes there's a situation where laying wires or physically connecting network nodes is impractical. Here are three instances when an organization would require a wireless LAN[6-9]. A marketing person needs anytime, anywhere communications capability in order to access e-mail and Internet-based applications, from any room in the office. A corporate executive needs network access for his notebook as he moves from his desk to the conference room to the boss's cabin. Desktops need to be instantly connected to the LAN. In all three cases, network connectivity can be established instantl y using WLAN technology[10-18]. WLAN, a complement to wired LAN, uses radio frequencies to transmit and receive data over the air. WLAN is represented by the 802.11 standard that forms an efficient data communications system. There are different types of antennas used in Wireless LAN systems which include Omni directional, Yagi UDA, Parabolic or dish and Patch antennas. Of all these, taking the cost and size of the antenna into consideration Microstrip Patch antennas serve the best purpose. In this project, we have deigned microstrip patch antenna for 2.4GHz. since most of the papers concentrated on designing the WLAN antenna for dual frequency here we have focused on design of microstrip patch antenna for Wireless LAN users and made a comparison using different feeding techniques and fabricated two microstrip patch antenna using two different feeding and tested the results[19- 23]. II. MICROSTRIP PATCH ANTENNA Microstrip Patch antenna consists of a radiating patch on one side of a dielectric substrate which has a ground plane on the other side as shown in fig 1. The patch is generally made of conducting material such as copper or gold and can take any possible shape. The radiating patch and the feed lines are usually photo etched on the dielectric substrate [24]. In order to simplify analysis and performance prediction, the patch is generally square, rectangular, circular, triangular, and elliptical or some other common shapes. For a rectangular patch, the length L of the patch is usually 0.3333λ 0 < L < 0.5λ 0 , where λ 0 is the free-space wavelength. The patch is selected to be very thin such that t<< λ 0 (where t is the patch thickness). The height h of the dielectric substrate is usually 0.003λ 0 ≤ h ≤ 0.05λ 0 . The dielectric constant of the substrate (ε r ) is typically in the range 2.2 ≤ ε r ≤ 12. B. Karthik * ,S.P.Vijayaragavan 2 and M.Sriram 3 1Assistant Professor, ECE Department, BIST, BIHER , Bharath University, No:173, Agaram Road, Selaiyur, Chennai-73; karthik.ece@bharathuniv.ac.in 2 Assistant Professor, EEE Department, BIST, BIHER , Bharath University, No:173, Agaram Road, Selaiyur, Chennai-73; vijayaragavan.eee@bharathuniv.ac.in 3Assistant Professor, CSE Department, BIST, BIHER , Bharath University, No:173, Agaram Road, Selaiyur, Chennai-73; msr1sriram@gmail.com International Journal of Pure and Applied Mathematics Volume 118 No. 18 2018, 25-33 ISSN: 1311-8080 (printed version); ISSN: 1314-3395 (on-line version) url: http://www.ijpam.eu Special Issue ijpam.eu 25