IOSR Journal of Electronics and Communication Engineering (IOSR-JECE) e-ISSN: 2278-2834,p- ISSN: 2278-8735.Volume 10, Issue 1, Ver. II (Jan - Feb. 2015), PP 44-49 www.iosrjournals.org DOI: 10.9790/2834-10124449 www.iosrjournals.org 44 | Page Design and Analysis of Single Microstrip Patch Antenna with Proximity Coupler Fed Technique for Wireless LAN Application Nuraiza Ismail, Suziyani Rohafauzi, Rina Abdullah, Suziana Omar (Department of Electrical Engineering / Universiti Teknologi Mara (UiTM), Malaysia) Abstract: This paper presents an analysis and designing single patch microstrip antenna with proximity coupler fed technique at 2.4 GHz resonant frequency appropriate for wireless LAN (WLAN) application. The software used to simulate the patch antenna is Computer Simulation Tools (CST) Microwave Environment. This antenna is fed by a 50 Ω single microstrip line feeding based on quarter wave impedance matching technique with width 1.68 mm. In this paper, the effects of antenna parameters like the frequency, return loss, voltage standing wave ratio (VSWR) and gain (dB) are analyzed by using proximity coupler fed technique. The construction of the antenna consists of the microstrip feed line on a substrate proximity coupled to a single rectangular microstrip patch etched in top of surface. The dielectric constant of antenna is 3, the tangent loss 0.03 and thickness of the antenna is 0.76 mm. Keywords: patch antenna, proximity coupler fed technique, return loss, VSWR, WLAN I. Introduction Microstrip antenna have been one of the most innovative topics in antenna theory and design in recent years, and are increasingly finding application in a wide range of modern microwave systems [1]. It provide small size antennas as there is much acute space available in these devices due to their compact sizes [2-4]. The microstrip patch antennas are well known for their performance and their robust design, fabrication and their extend usage [5]. Microstrip antennas are spreading widely in all the fields and areas and now they are becoming in the commercial aspects due to their low cost of the substrate material and the fabrication . There are many applications of microstrip patch antenna due to the increasing of their usage, such as mobile and satellite communication application, Global Positioning System (GPS) application, Radio Frequency Identification (RFID) application, radar application, telemedicine application and so on . Microstrip patch antennas are widely used because of their many advantages, such as the low profile, light weight and conformity. However, patch antennas have a main disadvantage which is narrow bandwidth [6] . The basic construction of microstrip patch antenna consists of a radiating patch on one side of a dielectric substrate which has aground plane on the other side [7]. Recently, wireless local area network (WLAN) applications are very popular. WLANs can achieve lower transmission latency in the presence of more powerful networks [8] and also capable of providing a high data rate to the end user. The frequency of 2.4 GHZ offers a data rate up to 11 Mb/s [9]. Microstrip patch antennas have several well-known feeding techniques, which are coaxial probe fed (CPF), microstrip transmission line fed (TLF), proximity coupled fed (PCF) and aperture coupled fed (ACF). In proximity coupler fed microstrip patch antennas [10] technique, offer various advantages conventional edge or coaxial probe fed patches. It allow the patch to exist on a relatively thick substrate for improve bandwidth. The feed line with thinner substrate reduces the spurious radiation [1] and coupling. An advantage of proximity coupling is that it provides large bandwidth and low spurious radiation [11]. The dielectric layers need the proper alignment and increase the overall thickness of the patch antenna. In this paper, Figure 1 shows the geometric structure of a single patch antenna with proximity couple fed. The configuration of the proposed antenna consists of two substrates, a top substrate called the antenna substrate and a bottom substrate called the feed substrate [12]. On the top of feed substrate, the feed line is designed to have a characteristic impedance of 50 Ω. The bottom of feed substrate has a copper ground plane. The antenna substrate has a copper patch etched on it. Figure 1: Geometry of single patch antenna with proximity coupler fed