# INTRODUCTION ireless communication was introduced in 19 th century. It has progressed toward becoming fastest growing sector of communication area. In wireless communication data is transmitted and received without using cables and wires. The wireless innovation has changed from analog first generation communication system and is about to an advanced fifth generation. Nowadays, the wireless communication innovation is facing the expanding interest of high transmission data rate, scalability, and efficiency. [1][2][3] In 1897, Marconi was the first scientist to exhibit that it was conceivable to set up a ceaseless correspondence stream with boats that were cruising forward, the remote innovations that, make progressing correspondence workable for us have been developed strikingly [4][5]. Wireless systems are playing a very important role in industries, medical, and in scientific field. The new age of cost-effective wireless communication innovation has been driven by relatively bringing down equipment and software cost and low power utilization [6][7][8]. However, these wireless technologies and remote advances have generally low information rate and perform its operation within a closed wireless communication network. These wireless technologies or we can say remote innovations operate or work inside extensive variety of frequency bands called as the ISM radio band [9][10][11]. ISM refers to Industrial, Scientific, and Medical radio band which are saved for the utilization of industries, scientific, and medical requirements. These frequency bands are unlicensed because it can be exploited according to different regions, by any person. ISM band are accepted band for worldwide operations. The bands which are mostly used are 2.45 GHz, 915 MHz, 868 MHz, and 433.92 MHz in the sward of Internet of Things and home [12][13][14]. In numerous research papers, antenna was outlined and manufactured to fulfill the coveted outcomes and working recurrence. There were numerous issues and disadvantages of the composed antenna. Some of the issues are antenna large size, its manufacturing cost; one antenna can be connected for just a single application [15][16][17][18] etc. To overcome the problem of expansive size of an antenna, applicable for more than one application, dual band antenna, which enhances the conventional patch antenna is required. In this paper the design and fabrication of a miniaturized dual band antenna using split ring and modified ground structure for ISM band application has been presented. We have shown the comparison of simulated results and experimental results. # II. # Antenna Design An efficient technique to build the antenna of large bandwidth is the use of modified ground plane. To include the applications of ISM as a modified ground plane strategy a rectangular patch and a narrow slit is made in the ground plane. In this outline of antenna a ground plane of patch antenna some surrendered shape is presented and relying upon the distinctive measurement, shape, and size of the defect (slots) the shielded current appropriation will get exasperate. The principle point of the proposed work is to upgrade and improve the conventional rectangular patch antenna performance at 2.45 GHz and 5.8 GHz frequency band W for ISM applications using split ring and modified ground structure. The material utilized for substrate is FR-4 lossy, for ground, and for patch PEC (pure electric conductor) material is used. The parameters of ground, patch and substrate of the proposed receiving wire are calculated using the mathematical formulas of micro strip patch antenna. Fig. 1 shows the structure of the proposed antenna and Fig. 2 shows the simulated structure of the antenna. Design parameters were calculated using design equations given from (1) to ( 5) and listed in Table-1 which were used in simulation. # a) Measured And Simulated Results # i. Return loss and Antenna Bandwidth The measured and simulated return loss characteristics are shown in Fig. 3 (a) and (b) representing that the proposed antenna shows a return loss of -16dB at 2.45GHz and -23.98 dB at 5.8GHz which is a good agreement. Dimensions of designed antenna. Table 1: Fig. 3(a): Return loss curve for 2.45GHz The antenna resonates from 2.0917GHz -2.5154GHz with center frequency 2.45GHz and 4.4327GHz -6.008GHz with center frequency 5.8 GHz as shown in Fig. 3(a) and Fig. 3(b) which is pertinent for application in ISM. # b) Directivity Directivity measures the aggregate amount of energy which is radiated from antenna in a particular course, in fact the maximum radiated energy. Generally directivity is always greater than 1 but on account of an isotropic antenna which is having directivity equivalent to 1. An antenna which is having directivity equivalent to 1 is called directive antenna. This antenna design gives the directivity at frequency 2.45GHz as shown in Fig. 4 # c) Gain Ratio of intensity in a given direction to the radiation power that would be achieved from it if power is radiated by the antenna isotropically. The simulation outcomes of the gain are shown below and the gain obtained is 1.13dB at 2.45 GHz and 3.685dB at 5.8GHz. The proposed antenna resonates from 2.0917 GHz -2.5154 GHz which is covering the bandwidth range 2.4GHz-2.5GHz with center frequency 2.45 GHz and 4.4327 GHz -6.008GHz covering the bandwidth range 5.75GHz-5.875GHz with center frequency 5.8 GHz which is applicable for application in ISM as shown in the above figures. The S11 parameters of fabricated antenna are shown above which are tested in vector network analyzer at resonant frequency of 2.41 and 5.89GHz. The VSWR ratio of 2.41GHz and 5.89GHz frequencies is 1.54 and 1.27 respectively. Smith chart speaks that how the receiving wire impedance differs with recurrence. The above table is about the examination of recreated result and the testing result. The deliberate and mimicked return loss qualities of the preferred antenna are appeared in Fig. 4. These are -16.75dB and in case of experimental result it is -34.6dB at 2.45GHz, at 5.8GHz expected return loss is -23.98dB and in case of experimental result it is -38.1dB. The bandwidth got amid the reenactment of an antenna in CST programming first bandwidth range got is 2.03-2.49GHz and second bandwidth range got is 4.45-6GHz which is covering the frequency range of ISM. While manufactured antenna gives recurrence of 2.41GHz and 5.89GHz. Simulation process is giving VSWR range in between 1 and 2 at dual frequency and experimental result is giving VSWR of 1.54 at 2.45GHz and 1.27 at 5.8GHz. By contrasting the aftereffects of recreation process and exploratory process we can infer that exploratory outcomes are far superior to simulation result. # Global Journal of Researches in Engineering ( ) Volume XIX Issue IV Version I # III. # Comparison Table IV. # Conclusion In light of the conclusions, results, and limitations of the proposed work, future work can be completed are as follows: In the antenna designed with split ring and modified ground. There are various unsolved issues and to be tended later on for further improvement in this specific area. The advancement which should be possible includes minimization of unwanted leakage of radiation through the modified ground and this should be possible by adjusting the shape, structure or reconfiguring the shape of antenna. Optimization of modified ground can be done to evade clashes with radiating mode. In future diodes can also be utilized or placed in slots to perform the antenna at a particular frequency band for specific applications, just by switching on and off the diodes. By using extraordinary and unique configuration of structure, using different material of dielectric substrate the work can be expanding in this work. In future different slots on the ground and on patch can be designed for getting better and different result. Structure of patch can also be changed according to get better result. Firstly a miniaturized dual band antenna with split ring and modified ground structure has been designed for the Industrial, scientific and medical applications. The various parameters like return loss, VSWR, directivity, gain, bandwidth and operating frequency are studied for antenna designing. Initially, the work starts with the designing of simple patch antenna with a single slot in ground to obtain center frequency of 2.45GHz frequency. Modification is done in ground's dimensions Global Journal of Researches in Engineering ( ) Volume XIX Issue IV Version I that are in width and in its length. The next step is to design split ring on the patch which gives center frequency of 5.8 GHz. It is also concluded that physical parameters like resonate length and width of slot in ground effects the results of the antenna. It can be clearly seen that varying dimensions like length, width of respective substrate, patch, and ground in the right way gives optimized results for desired results. 1![Fig. 1: Proposed design of microstrip antenna](image-2.png "Fig. 1 :") 3![Fig. 3 (b): Return loss curve for 5.8GHz](image-3.png "Fig. 3 (") ![Fig. 4(a): Directivity plot at 2.45 GHz](image-4.png "") 5![Fig. 5(a): 3D Gain at 2.45 GHz](image-5.png "Fig. 5 (") 5![Fig. 5(d): Gain at 5.8GHz d) Voltage standing Wave Ratio This parameter is used for matching and tuning of the transmitting antennas. It defines how well the antenna is matched with the transmission line it is associated with. Fig. 6(a) and (b) is representing the value of VSWR lies b/w 1 & 2.](image-6.png "Fig. 5 (") 6![Fig. 6(a): VSWR lies between 1-2 at 2.45 GHz](image-7.png "Fig. 6 (") 89![Fig. 8: S11 parameter of fabricated antenna, tested in VNA](image-8.png "Fig. 8 :Fig. 9 :") ![](image-9.png "") 2ParameterSimulation ResultsExperimental ResultsBandwidth 12.03GHz-2.49GHz2.41GHzBandwidth 24.45GHz-6GHz5.89GHzVoltage Standing Wave Ratio 2.4GHz1.461.54Voltage StandingWave Ratio at1.231.275.8GHzReturn Loss at 2.45GHz-16.75dB-34.6dBReturn Loss at 5.8GHz-23.98dB-38.1dB © 2019 Global Journals Design and Fabrication of Miniaturized Dual-Band Antenna using Split-Ring & Defected Ground Structure for ISM Band Applications F © 2019 Global Journals Design and Fabrication of Miniaturized Dual-Band Antenna using Split-Ring & Defected Ground Structure for ISM Band Applications * CPW-fed slot antenna with wide radiating apertures XDing AFJacob 10.1049/ip-map:19981629 IEE Proceedings -Microwaves, Antennas and Propagation Feb. 1998 145 * Broadband CPW-fed square slot antennas with a widened tuning stub Horng-DeanChen 10.1109/TAP.2003.814747 IEEE Transactions on Antennas and Propagation Aug. 2003 51 * Compact circular microstrip antenna for conical patterns CBRavipati doi: 10.1109 /APS. 2004. 1330181 IEEE Antennas and Propagation Society Symposium Monterey, CA, USA 2004. 2004 * Wide-band slot antennas with CPW feed lines: hybrid and log-periodic designs UBhobe CLHolloway MPiket-May RHall 10.1109/TAP.2004.834425 IEEE Transactions on Antennas and Propagation Oct. 2004 52 * Wideband Printed Microstrip Antenna for Wireless Communications PSarin NNassar VDeepu CKAanandan PMohanan KVasudevan doi: 10. 1109/LAWP. 2009. 2026193 IEEE Antennas and Wireless Propagation Letters 2009 8 779781 * Bandwidth Enhancement of Printed E-Shaped Slot Antennas Fed by CPW and Microstrip Line ADastranj HAbiri 10.1109/TAP.2010.2041164 IEEE Transactions on Antennas and Propagation April 2010 58 * Synthesis of Elliptical Patch Microstrip Antenna Using Artificial Neural Network YAnuj JigarModi NilimaMehta Pisharody 2013 IEEE * Ultra wide band three layer microstrip patch antenna using single layer helical resonating metamaterial cover SEMendhe YPKosta 10.1109/WOCN.2013.6616250 Tenth International Conference on Wireless and Optical Communications Networks (WOCN) Bhopal 2013. 2013 * Rectangular patch antenna for wireless LAN frequency with periodic DGS structure SRoy PBSaha MBhowmik 10.1109/ICCSP.2015.7322667 2015 International Conference on Communications and Signal Processing Melmaruvathur 2015 * Compact dual band slot loaded circular mi-crostrip antenna with a superstrate DDKrishna MGopikrishna CKAanandan PMohanan KVasudevan Progress In Electromagnetics Research, PIER 83 2008 * Design and analysis of U-Shaped micro strip patch antenna SKannadhasan ACShagar 10.1109/AEEICB.2017.7972333 2017 Third International Conference on Advances in Electrical, Electronics, Information, Communication and Bio-Informatics (AEEICB) Chennai 2017 * A broad-band CPW-fed strip-loaded square slot antenna Jyh-YingChiou Jia-YiSze Kin-LuWong 10.1109/TAP.2003.812232 IEEE Transactions on Antennas and Propagation April 2003 51 * CChulvanich JNakasuwan NSongthanapitak NAnsntrasirichai TWakabayashi 2007 * Design of narrow slot antenna for dual frequency PIERS Online 3 7 * Design of multifrequency microstrip antennas using multiple rings APal SBehera KJVinoy IET Microwaves Antennas and Propagation 3 2009 * Compact dual band slot loaded circular microstrip antenna with a superstrate DDKrishna MGopikrishna CKAanandan PMohanan KVasudevan Progress In Electromagnetics Research 83 2008 * A Broadband Center-Fed Circular Patch-Ring Antenna With a Monopole Like Radiation Pattern FAl-Zoubi AYang Kishk 10.1109/TAP.2008.2011406 IEEE Transactions on Antennas and Propagation March 2009 57 * Wideband Printed Monopole Design Using a Genetic Algorithm MJohn MJAmmann 10.1109/LAWP.2007.891962 IEEE Antennas and Wireless Propagation Letters 2007 6 * Circularly-Polarized Wide Slot Antenna Loaded With a Parasitic Patch JRow SWu 10.1109/TAP.2008.928769 IEEE Transactions on Antennas and Propagation Sept. 2008 56