International Journal of Advanced Information Science and Technology (IJAIST) ISSN: 2319:2682 Vol.6, No.4, April 2017 DOI:10.15693/ijaist/2017.v6i4.01-06 1 Slotted and Miniaturized Patch Antenna for WLAN and WiMAX Applications Nagabhushana H. M. Research Scholar, Department of ECE Jain University, Bengaluru, Karnataka, India bhushana.hm@gmail.com Dr.Thangadurai N. Professor, Department of ECE Jain University, Bengaluru, Karnataka, India mrgoldjain2015@gmail.com Dr.C.R. Byrareddy Professor, Department of ECE Bangalore Institute of Technology, Bengaluru, Karnataka, India byrareddycr@yahoo.co.in Saleem Ulla Sharief P.G. Scholar, Department of ECE UVCE, Bengaluru, Karnataka, India saleem_shariff@yahoo.co.in Abstract— The properties of Microstrip patch antennas such as low profile, easy fabrication, less cost and conformability well suited and popularly used in wireless devices. A small slotted dual band microstrip patch antenna for wireless applications is presented in this paper. The IEEE operating bands 2.4/5.2 GHz wireless local area network (WLAN)/ worldwide interoperability for microwave access (WiMAX) are covered by this proposed antenna. The antenna can be fed by direct probe feeding using a 50 ohm microstrip line. The parametric analysis such as return loss, directivity, bandwidth, gain and VSWR of micorstrip patch antenna with meandered slots are analyzed using high frequency structure simulator (HFSS). Measured return loss and radiation patterns are observed to be omnidirectional, moderate gain and dual band frequencies suitable for mobile handsets. The overall size of the antenna is 15mm×25mm×1.6mm, fabricated on flame resistant-4 epoxy (FR4) substrate of dielectric constant 4.4. The antenna provides two useful impedance bands with good efficiency. The antenna size reduction is more than 60%. The first band resonates at 2.4 GHz with return loss of -19.79 dB. Hence first band finds application in WLAN. The second band resonance is at 5.2 GHz with return loss of -28.97 dB. WiMAX uses this band. The operation of the antenna is compared along with measured and simulated results. Good validation has been found in measured results and simulated results. Index terms -Slot, Patch, Mobile, Return loss, VSWR, HFSS, Dual band, Microstrip. I. INTRODUCTION Wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) are widely used in modern wireless communication technology for mobile devices [1,3,12,13]. In order to satisfy the various wireless communication protocol systems, mobile phones have wireless data connectivity for various business and personal applications. The most popular standard is WLAN/IEEE 802.11b uses the 2.4 GHz band, which operates in the same frequency range. On the other hand WiMAX/IEEE 802.16 standard that covers 5.2 GHz band, which provides wireless data transfer from single node to multinode links for portable and smaller mobile internet connectivity. This leads to great demand in designing single compact antenna for mobile systems. Microstrip antennas have numerous advantages such as low profile, less cost, light weight, easy fabrication and modeling. A triple band open L-slot with slit and a strip antenna which provides better impedance, and generates verity patterns of polarizations both linear and circular. Slit and strip mender line antennas has been designed to operate tri bands to meet the requirements for wireless applications [1]. Main issue with a coplanar waveguide (CPW) –fed slot antenna is to provide an easy impedance matching and bandwidth enhancement. So for several impedance matching techniques are proposed based on the change of the slot shapes and also reduced radiation hazard for mobile handset. Monopole antenna have been adopted and studied extensively for wideband communication systems because of their features such as simple structure, small size, wide impedance bandwidth and omnidirectional radiation patterns [2]. Ting WU et al [3] demonstrates a compact triband microstrip monopole antenna composed of a partial ground and Y-shaped radiated patch that consists of two unequal monopole arms and an embedded circle monopole, which gives good polarization characteristics and improves the impedance bandwidths to cover the frequency bands. The proposed paper explains shorted patch elaborated design to get flexibility in the desired frequency for the two operating ranges and tune it for custom applications. More attention has been given to the miniaturization of antenna for mobile systems where physical size of a device is important, which gives better directivity and polarization [4]. A compact inset-fed dual band microstrip antenna has designed to study the effects of varying the slots size of the radiating elements. The impedance bandwidth, Excellent return loss, radiation patterns, high gain and less cross- polarization has been reached [9].