International Journal of Electrical & Electronics Research (IJEER) Volume 4, Issue 3, Pages 80-84, September 2016, ISSN: 2347-470X Comparison and Performance Evaluation on Microstrip Patch Antenna for WLAN Application Meenal Kate1, Anjana Goen2 M Tech Scholar1, Associate Professor2 Department of Electronics, Rustamji Institute of Technology, Tekanpur, Gwalior, India Meenalkate17@gmail.com1, anjana@rjit.org2 Abstract- This paper present a comparative study shown in figure 1 [17]. The rectangular radiating patch & circular radiating patch was found to exhibit good radiation characteristics, simple to design and compact in size when compared to other microstrip patch shapes [4] and CPW-fed technique [5] is used for transmission line i.e. transmitting or receiving the electromagnetic (EM) waves. between two works proposed for microstrip patch antenna dual band operations. The comparison is made between a dual-band planar antenna with a compact radiator for 2.4/5.2/5.8-GHz Wireless Local Area Network (WLAN) applications and a printed circular microstrip patch antenna with a four rectangular shape strip and co planar rectangular ground plane antenna. The comparative analysis between these two antennas consist of following parameters such as dimensions, bandwidth, gain, return loss, directivity etc. Keywords- Circular Ring Microstrip patch antenna (CRMPA), Dual Band Microstrip Patch Antenna, Microstrip Patch Antenna (MPA), Multiband Antenna, Wireless Local Area Network (WLAN) Antenna. 1. INTRODUCTION Figure 1: Different Shapes of Patch Antenna Antenna is an impedance matching device which matches the characteristic impedance between source terminal and load terminal antenna is also called as transducer which converts electrical signals in to electromagnetic waves during transmission and vice versa during reception. 2. ANALYSIS OF REFERENCE PAPER Antenna Design: In this paper, a planar dual-band antenna using a very compact radiator to cover all the 2.4/5.2/5.8 GHz WLAN operating bands is proposed. The radiator consists of an L-shaped and E-shaped elements resonating at around 5.5 and 2.44 GHz, respectively. The L-element is microstrip fed. However, the E-element is placed very close to the L–element and is coupled-fed through the E-element. Since only one feed point is used for the two separate elements, the overall size is very compact. The antenna is designed and studied using the EM simulation tool CST. The Microstrip Patch Antennas (MPA) are the most widely used for the last few years due to their attractive features such as light weight, low volume, ease in fabrication and low cost. Some wireless communications applications of antennas are required to simultaneously operate for Wireless Local Area Network (WLAN) and Worldwide Interoperability for Microwave Access (Wi-MAX) technology. The specified spectrum for WLAN is centered at 2.4, 5.2, and 5.8 GHz, and for Wi-MAX at 2.5, 3.5, and 5.5 GHz [3]. Currently WLAN and Wi-MAX is the most emerging technology for accessing wireless communication. In recent years, several reports have appeared about the development of low-profile multiband antennas. However, most of them are relatively large and/or do not provide desired bandwidths. One method of improving the bandwidth and reducing the size is to use a planar microstrip antenna with slots and strips on the patch and ground plane. Among different shapes of radiating patches such as square, rectangular, circular, ellipse etc as Figure 2: Microstrip Patch Antenna with L & E Element [2] 80 International Journal of Electrical & Electronics Research (IJEER) Volume 4, Issue 3, Pages 80-84, September 2016, ISSN: 2347-470X Parameter Study: Fig. 1 shows the 3-D view of the dualband antenna which has a radiator with an area of 8 x 11.3mm 2, the microstrip-feed line has a width of 1.8 mm to achieve characteristic impedance of 50. (Note that the length e-feed line depends on the space available on the particular wireless device where the antenna is installed.) The geometry of the radiator is shown in Fig.2 which consists of two radiating elements. These elements look like the letters E and L and rotated by 90 and so are denoted here as an Eand L-elements, respectively. The prefixes and used to indicate the dimensions of Fig.2 denote the widths and lengths, respectively, in different parts of the elements. The L–element is direct-fed by the feed line at “A” marked on Fig. 2. It generates a wide frequency band at 5.5 GHz for the higher WLAN bands at 5.2 and 5.8 GHz. The E-element, having a modified inverted F- structure, is coupled-fed from the L -element via the small gap and is shorted to ground using a via with diameter of 0.3 mm marked as “G” on the shorting element of Fig. 2. It generates a band at around 2.44 GHz for the lower band of the WLAN system. Thus the antenna has dual-band operation to cover all the 2.4/5.2/5.8 GHz WLAN bands. Since only one feed point is required for the two separate elements which are closely packed together, the radiator size is very compact. The antenna is designed on a substrate with a relative permittivity of 3.5 and a loss tangent of 0.02, and optimized using computer generated at a lower frequency of 2.44 GHz and the resonance at 7 GHz was shifted down to around 5.5 GHz. Figure 3: Return Loss Analysis of Reference Antenna 3. ANALYSIS OF PROPOSED ANTENNA Antenna Design: Circular ring microstrip patch antenna with rectangular shaped strip is printed on the one side of the FR4 lossy substrate and the ground plane is also located on the same side of the substrate. The proposed structure of the CRMPA with rectangular shaped strip is designed on CST. The dimensions of the CRMPA with ground plane layer with an area of 40 x 40 mm 2. Single rectangular strip line of width Ws and two equal ground planes are used as CPW-fed transmission line. Two equal finite ground planes, each with dimensions of length Lg and width Wg are placed symmetrically on each side of the strip line. The circular ring microstrip patch is connected centrally at the end of the CPW feed line. By properly selecting the antenna’s geometric parameters, dual-frequency operation is achieved and even small size of antenna is also obtained Four Rectangular strips are placed mirror image to each other at a centre of circular ring patch as shown in the Figure 3. Simulation Results: The overall dimension of reference antenna is with a compact area of only 8 x11.3 mm 2 The S11 and radiation pattern is shown in figure 3, the simulated efficiencies are 83 % (for 802.11a) & 85% (for 802.11b/g). Peak gain of reference antenna is 1 & 1.98 dBi respectively for both bands. It covers the bandwidth of 2.39 GHz -2.44 GHz for lower band and 5.23GHz-5.5 GHz for higher band. Figure 4: Structure of the Proposed CRMPA 81 International Journal of Electrical & Electronics Research (IJEER) Volume 4, Issue 3, Pages 80-84, September 2016, ISSN: 2347-470X Simulation Results: The proposed CRMPA design is simulated using the CST Microwave Software. Figure 4 shows the simulated return loss of the proposed antenna from1 to 6 GHz. The achieved simulated return loss of the proposed CRMPA is -23.6dB at a frequency 2.37 GHz having the lower frequency (fL) of 2.186GHZ and higher frequency (fH) of 2.527GHz and 22.7dB at a frequency 5.45GHz having the lower frequency (fL) of 5.239 GHZ and higher frequency (fH) of 5.653GHz respectively. The obtained bandwidth of proposed antenna is 341MHz & 414MHz. Figure 5: Simulated return loss of proposed CRMPA at 2.37 GHz & 5.45 GHz resonant frequency Figure 6-Gain Analysis for Lower Band and Higher Band 82 International Journal of Electrical & Electronics Research (IJEER) Volume 4, Issue 3, Pages 80-84, September 2016, ISSN: 2347-470X TABLE 1: Comparative Analysis S. No. 1 PARAMETER Dimension REFERENCE ANTENNA 40x30 mm2 PROPOSED ANTENNA 40x40mm 2 Design Three layer Two layers 3 Efficiency 4 Gain 5 Bandwidth 6 Directivity 83%(802.1a) 85%(802.b/g) 1 (802.11a) 1.98(802.11b) 2.39-2.44GHz (802.11a) 5.23-5.5GHz(802.11b/g) -------- 97%(802.11a) 85.56%(802.11b) 2.4 (802.11a) 4.8(802.11b/g) 2.18-2.52GHz (802.11a) 5.23-5.65GHz (802.11b/g) 2.5 (802.11a) 5.5 (802.11b/g) 4. CONCLUSION 4. Mahdi Moosazadeh and Sergey Kharkovsky, “Compact and Small Planar Microstrip Antenna with Symmetrical L-Shaped and U-Shaped Slots for WLAN/WiMAX Applications”, IEEE antennas and wireless propagation letters, vol. 13, 2014. 5. S. Muzahir Abbas, Istaqlal Ahmed, Hamza Nawaz, Ilyas Saleem, “Meandered Corner Planar Monopole Antenna for UWB Applications”, Scientific & Academic Publishing, Vol. 2, No. 3, 2012. 6. Jyoti Ranjan Panda, Rakesh Singh K shetrimayum, “Parametric Study of Printed Rectangular Microstrip Antennas”, International Journal of Recent Trends in Engineering, Vol. 1, No. 3, 2009. 7. N. Suresh Babu, “Design of Compact Printed Rectangular Monopole Antenna and U Shaped Monopole Antenna for LBand and S-Band Applications” International Journal of Electronics Signal and System, Vol. 1, No. 3, 2012. 8. N.P. Agarwal, G. Kumar, K. Ray, “Wide-Band Planar Microstrip, “ IEEE Transaction on Antenna Propagation, Vol. 46, No. 2, 1998. 9. R. Jothi Chitra and V. Nagarajan, “Double L-Slot Microstrip Patch Antenna Array for WIMAX and WLAN Applications” IEEE Transactions on Antennas and Propagation, Vol. 39, pp 1026-1041, 2013. 10. Bharath Kelothu and K.R. Shubashmi,” A Compact HighGain Microstrip Patch Antenna for Dual Band WLAN Application” IEEE Transaction on Antenna and Wave Propagations 2012. 11. Bipa Datta, Gaur Sundar Sarkar and Arnab Das,“Compact Monopole Patch Antenna for X and Ku Band Microwave Communication” International Conference Communication Network (ICCN) IEEE 2015 on pp 65-70, 2015. 12. Swaraj Panusa and Mithilesh Kumar, “Dual Band H-Slot Microstrip Patch Antenna WLAN Applications” IEEE Transaction, on Antenna and Wave Propagations Jan 2015. 13. Tommy Haryadi, “A Coplanar Waveguide (CPW) Wideband A configuration of single-layer printed circular ring microstrip patch antenna with a rectangular shape strip with a co planar waveguide fed ground plane on the FR4 lossy substrate to obtaining two separate wide operating bands for WLAN application has been investigated in proposed paper. It has been observed that return loss of the antenna is increased with proper dimension of four microstrips. Position of the port is a frequency independent parameter. It only varies the return loss without affecting the centre frequency. The application of proposed antenna is found to be in WLAN. Antenna Gain in lower and higher frequency band is also calculated as shown in figure 5. After comparing both papers it has been concluded that as the dimensions of proposed antenna is larger with respect to proposed antenna but number of layers are reduced. Also, from Table 1 efficiency, gain, Bandwidth is also improved in our paper. REFERENCES 1. CA Balanis, Antenna Theory Analysis and Design (John Wiley & Sons Inc, 2nd edition, 1997). 2. Xiao Lei Sun, Li Liu, S.W. Cheung,” Dual-Band Antenna With Compact Radiator for 2.4/5.2/5.8 GHz WLAN Applications” IEEE Transaction on Antenna Propagation, Vol. 60, No. 12, 2012. 3. CST (Computer Simulation Technology) Microwave Studio 2010. 83 International Journal of Electrical & Electronics Research (IJEER) Volume 4, Issue 3, Pages 80-84, September 2016, ISSN: 2347-470X 14. 15. 16. 17. 18. 19. 20. Microstrip Antenna” IEEE Transactions on Antenna and Wave Propagations, Aug 2013. 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