OCTAGON SHAPED MICROSTRIP PATCH ANTENNA FOR DUAL BAND APPLICATIONS zyxwvu S.Mridula, Binu Paul, C.K.Aanandan and P.Mohanan* Department of Electronics, Cochin University of Science and Technology Cochin 682 022, India Email :mohan@doe.cusat.edu zyxwvut , drmohan@cusat.ac.in ABSTRACT : The paper proposes an octagon shaped Microstrip Patch Antenna suitable for dual band applications. The striking features of this compact, planar antenna are sufficient isolation between the two operating bands and zyxwv an area reduction of - 29% in comparison to a conventional circular patch antenna operating in the same band. 1. INTRODUCTION Recent breakthroughs in wireless communication technology focus on a single low cost mobile terminal equipped to operate in different regions of the world, in different frequency bands. Therefore, there is an immediate need for a single, multi band - multi function handset allowing users to switch freely between existing cellular networks. Dual frequency behavior can be obtained through several techniques, such as multilayer substrates, addition of parasitic elements, loading the patch with reactive elements, etc. [l]. Basically, microstrip patches require two elements of different dimensions, resonating in the required frequency bands to achieve dual band characteristics. The potential of an irregular shaped planar antenna has been proposed for multi - band operation [2]. Perturbation of the shape of a conventional microstrip patch antenna in a prescribed manner also results in multi - band operation [3]. But, most of these techniques achieve dual frequency operation by either increasing the patch size or using complicated manufacturing methods. This paper focuses on a compact octagonal microstrip antenna designed to operate at 1.8GHz and 2.4GHz. The frequencies chosen for the study are those allotted for Mobile Communications and Blue tooth applications respectively. Bluetooth is a relatively new comer in the field of RF technologies for wireless communication. Bluetooth operates in the 2.4GHz ISM (Industrial Scientific Medical) frequency band zyxwvuts [4]. The frequency presently allotted for Mobile communication applications is 1.8GHz. Microstrip antenna is an ideal choice for these applications by virtue of its conformal and planar structure. zyxwv 808 0-7803-7330-8/02 $17.00 92oM IEEE