Quadrature Band and Penta-band MIMO Antenna By Mutually Coupling Non-radiating Edges V.V.Mapare S.V.Mapare G.G.Sarate Sinhgad Institute of Technology Sinhgad Institute of Technology Government Polytechnic Lonavala.Pune. Lonavala.Pune. Amravati mapare.vilas@gmail.com smapare@gmail.com ggsanshu@gmail.com Abstract-A rectangular microstrip antenna for quadrature band and penta-band is developed using a mutual coupling technique. Single rectangular microstrip is splitted into multiple resonators along the width and gap coupled to non-radiating edges. The proposed structure gives sufficient separation between the operating frequencies for quadrature band and penta-band. It covers the frequency range from 1900 MHz to 3 GHz covering Universal Mobile Telecommunication System (UMTS, 1920-2170 MHz), Wireless Local Area Network (WLAN, 2400-2483.5 MHz) and low band Worldwide Interoperability for Microwave Access (WIMAX, 2.5 to 2.8 GHz). Simulation results are presented and discussed. Keywords: Quadrature band, rectangular microstrip antenna, gap coupled rectangular microstrip antenna, multiple resonators, parasitic resonators, penta band MIMO antenna. I INTRODUCTION Quite a number of applications like modern day mobile communication systems, WLAN’s and GPS, vehicular, etc utilize several different frequency bands for communication[3]. So for these applications if a single antenna can be made to operate in required frequency bands the complexity of design could be reduced considerably[4]. The separation between resonance frequencies can be varied, primarily, by varying the resonance frequency of the individual elements. The resonance frequency of the MSA, for given substrate parameters, largely depends on its dimensions. So to change it’s resonance frequency the dimensions of the patch have to be varied. The resonance frequency of a RMSA primarily depends on its length. Therefore, if a RMSA is divided into smaller elements along the width keeping the length same, these smaller elements radiate at almost same frequency as the original RMSA leading to increase in bandwidth[2],[6],[7]. Also the number of resonances increases as the number of elements increases. By increasing the separation between the resonances, by approximately varying the length leading to variation of resonance frequency of elements, it is possible to obtain multiple frequency operation[1],[5]. The present paper deals with multiple resonator elements that are formed by splitting a single rectangular microstrip antenna along the width wherein by optimizing the gap coupling and resonating lengths of resonators yields quadrature band and penta band frequency operation. One of the element is co-axially fed while other parasites are gap coupled to its non-radiating edges[1], [8],[9]. II QUADRATURE BAND AND PENTA-BAND MIMO ANTENNA A. Configuration of six elements: Initially, a single RMSA resonant configuration is designed to resonant at a frequency of 2GHz. The patch dimension are calculated from formulas in [5] are L = 35mm and W = 46.07mm. The substrate thickness h = 0.159 and dielectric constant Єr = 4.3. This yields a bandwidth of 48MHz when the resonator is fed at x = 8.9mm using N type coaxial connector of diameter d = 3mm.This single RMSA is then splited into six equal width elements, the L3 element is fed using co-axial probe, while other five are gap coupled to its non-radiating edge .If length is same for all six elements they radiate at almost same frequency. For Multifrequency operation the lengths of the individual elements are varied as each element radiates. For triple length L2 and L5 was increased which add up to the frequency band as they radiate at frequencies closer to each other, the length of strip L5 is further increased so that it radiates at different resonant frequency. The length L2 is same as that of the L4 so their resonant frequencies are same. The difference between the lengths of different elements is small, the separation between the different resonance also decreases. Fig.1. shows the Four frequency response of six patch configuration with first resonant frequency at 1.99GHz and the fourth at 2.4GHz. Accordingly, Table I shows the performance of this configuration that includes the return loss in dB and the bandwidth of the individual resonant frequency. TABLE I. SIX RESONATORS FOR QUADRATURE FREQUENCY RESPONSE (ЄR = 4.3 , H = 1.59MM , TANΔ = 0.02 , W = 7.68MM, X =7MM) Lengths L (mm) Gaps,S (mm) fr1 1.991 RL1 -15.26 L1 = 36 S1 = 1.625 BW1 45 198 978-1-4673-4529-3/12/$31.00 c 2012 IEEE