Global Journal of researches in engineering Electrical and electronics engineering

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1 Global Journal of researces in engineering Electrical and electronics engineering Volume 11 Issue 6 Version 1. October 211 Type: Double Blind Peer Reviewed International Researc Journal Publiser: Global Journals Inc. (USA) Online ISSN: & Print ISSN: Wideband Inverted-F Double-L Antenna for 5 Applications By Abu Naim Rakib Amed, Al-Asan Talukder, Debabrata Kumar Karmokar Kulna University of Engineering & Tecnology (KUET), Kulna, Banglades Abstract - An Inverted-F Double-L (IFDL) antenna wit Omni- directional radiation pattern in te azimut plane is proposed. It provides an impedance bandwidt of 2.55 (5-755 MHz) below 1dB, wic easily covers te required universal 5 bandwidt for wireless local area network (WLAN), and worldwide interoperability for microwave access (WiMAX).Furtermore, te antenna as a simple structure and it occupies a small size of about mm2. Tis antenna also provides lower gain variation wit peak return loss of , and db at 5.2, 5.5 and 5.8 respectively. Keywords : IFA, low cost, wideband antenna, WLAN,WiMAX. GJRE-F Classification: FOR Code: Wideband Inverted-F Double-L Antenna for 5 Applications Strictly as per te compliance and regulations of : 211. Abu Naim Rakib Amed, Al-Asan Talukder, Debabrata Kumar Karmokar.Tis is a researc/review paper, distributed under te terms of te Creative Commons Attribution-Noncommercial 3. Unported License ttp://creativecommons.org/licenses/by-nc/3./), permitting all non commercial use, distribution, and reproduction in any medium, provided te original work is properly cited.

2 Wideband Inverted-F Double-L Antenna for 5 Applications Abu Naim Rakib Amed, Al-Asan Talukder, Debabrata Kumar Karmokar Abstract - An Inverted-F Double-L (IFDL) antenna wit Omnidirectional radiation pattern in te azimut plane is proposed. It provides an impedance bandwidt of 2.55 (5-755 MHz) below 1dB, wic easily covers te required universal 5 bandwidt for wireless local area network (WLAN), and worldwide interoperability for microwave access (WiMAX).Furtermore, te antenna as a simple structure and it occupies a small size of about mm2. Tis antenna also provides lower gain variation wit peak return loss of , and db at 5.2, 5.5 and 5.8 respectively. Keywords : IFA, low cost, wideband antenna, WLAN,WiMAX. I. INTRODUCTION I n recent years due to fabulous development of mobile wireless communication, systems suc as digital notepad, notebook and so on required broadband connections wit large transmission and receiver speeds troug wireless local area network (WLAN).Generally, te 2.4 GHZ ISM band utilized by te IEEE 82.11b and 82.11g standards but in tis case te WLAN equipment will suffer interference from baby monitors, wireless keyboards, microwave oven, Bluetoot devices and oter appliances tat use te same band. On te oter and, te oter frequency spectrum allowed for WLAN (5 ) ave muc wide band widt wit fewer disturbances from oter services. Moreover, 5 network can carry more data tan te 2.4. So, to meet te condition of less interference te design of te antenna become more sopisticated wic required aving some special properties suc as, small size, iger gain, Omni-directional radiationpattern and so on. In order to satisfy te above condition for 5 band antenna, several antennas are proposed. a monopole antenna wit a folded ground strips [1] as been proposed for WLAN application is capable to satisfy te wole 5 band but it is not small in size. Some of te antennas are also provide full coverage of 5 but tey are in large size [2-6] or Autor : A. N. R. Amed, Department of Electrical & Electronic Engineering, Kulna University of Engineering & Tecnology (KUET), Kulna-923, Banglades. naimeee_22@yaoo.com Autor : A.-A. Talukder, Department of Electrical & Electronic Engineering, Kulna University of Engineering & Tecnology (KUET), Kulna-923, Banglades. asan_5_eee@yaoo.com Autor : D. K. Karmokar, Department of Electrical & Electronic Engineering, Kulna University of Engineering & Tecnology (KUET), Kulna-923, Banglades. debeee_kuet@yaoo.com require a big ground plane [7-1].Altoug small size is acieved by antenna presented in te literature but tey suffered by inadequate coverage in 5 band [1,4,5,7,1]. Terefore, in tis article, we propose a compact wideband antenna for 5 Universal WLAN and WiMAX operations. From te simulation results, it provides a wider impedance bandwidt of 2.55 (5-755MHz) wic fully covers te 5.2/5.5/5.8 bands. Moreover it also gives an omnidirectional radiation patterns wit maximum measured peak antenna gains of 7.6, 7.14 and 6.53 dbi across te operating bands, respectively. Details of te proposed antenna design are described in tis study, and te related results for te obtained performance operated across te 5.2/5.5/5.8 bands are presented and discussed. II. ANTENNA GEOMETRY & DESIGN Te design variables for tis antenna are te eigt, widt, and lengt of te top plate, te widt and te location of te feed wire.in designing te broadband low profile antenna for 5 WLAN/WiMAX applications, we examine te possibility of increasing antenna bandwidt, gain and maintaining te input impedance near about 5 application bands wit simplifying its structure. Metod of moments (MoM s) in Numerical Electromagnetic Code (NEC) [11] is used for conducting parameter studies to ascertain te effect of different loading on te antenna performance to find out te optimal design were finest segmentation of eac geometrical parameter are used. Te antenna is assumed to feed by 5 connector. In our analysis we assume te copper conductor and te antenna was intended to be matced to 5 mpedance. Fig. 1 represents te basic geometry of te different antenna. For te simulation we consider printed circuit board (PCB) wit permittivity of ε r =2.2, substrate tickness of 1.58 mm and te dimensions of te ground plane considered as 6 6 mm2. Fig. 1(a) represents te general IFA were one leg of IFA directly connected to te feeding and anoter leg spaced s from te ground plane. An additional L branc is added in structure 2 wic sown in Fig. 1(b).In Fig 1(c) te limbs of L branc of structure 2 is extended and an additional L branc is coupled. Terefore structure 3 is termed as inverted-f Double-L antenna (IFDL antenna). ( F ) VI November Global Journal of Researces in Engineering Volume XI Issue v Version I 211 Global Journals Inc. (US)

3 Wideband Inverted-F Double-L Antenna for 5 Applications Wit te elp of resonant frequency teory of IFA and impedance matcing concept, we consider te dimension of te IFA l=16 mm, t=5 mm, =4 mm, 1=3 mm, d=2 mm and s=1 mm. Fig. 2 sows te effects of lengt l on te return loss as a function of frequency on te IFA of structure 1. From te simulated results wen l=16 mm, t=5 mm, =4 mm, 1=3 mm, d=2 mm and s=1 mm te variation of return loss wit frequency is not covering te wole 5 operating band (frequency ranges MHz) moreover te return loss is not so desirable. l t l t 1 l t 2 2 Global Journal of Researces in Engineering ( F) Volume XI Issue VI Version I November d Feed (a) Structure 1, (b) Structure 2, (c) Structure 3-3 Fig.2 : Return loss as a function of frequency for different types of antennas. After adding an additional L branc wit te structure 1 te performance of te return loss improves sligtly. However, wen we added anoter L branc wit structure 2, te performance of return loss improves dramatically. Fig. 3 sows te effects of l on te return loss of IFDL antenna, wen t=5 mm, =4 mm, 1=4 mm, 2=4 mm, s=1 mm and d=2 mm. From te figure we observed tat, for considering return loss te best performance of te IFDL antenna is obtained wen l=16 mm altoug l=16 mm and l=17 mm will cover te wole 5 band, teir return loss is not appreciable as l=16 mm. On te oter and, for l=14 mm and l=15 mm return loss is muc iger tan l=16 mm. Now maintaining l=16 mm we continue our advance analysis on te tap distance t as sown in Fig. 4 and we observe tat wen t=5 mm te IFDL antenna provides more negative return loss at te application bands tan oter values. Fig. 5 sows te effects of d on return loss wen te tap distance t=5 mm and lengt l=16 mm. Te best performance of return loss is obtained wen d=2 mm. s d Feed Fig.1 : Geometry of different antenna structure. Structure 1 Structure 2 Structure s Feed -4 Fig.3 : Effects of lengt l on te return loss as a function of frequency on te antenna structure of Fig. 1(C) t=3 mm t=4 mm t=5 mm t=6 mm t=7 mm d l=14 mm l=15 mm l=16 mm l=17 mm l=18 mm -3 Fig.4 : Return loss as a function of frequency wit te different tap distance t of te IFDL antenna of Fig.1(C) wen l=16 mm. s 211 Global Journals Inc. (US)

4 d=1 mm d=2 mm d=3 mm Fig.5 : Return loss as a function of frequency wit different value of d of te IFDL antenna of Fig. 1(C) wen t=5 mm and l=16 mm s=1 mm s=2 mm s=3 mm -3 Fig.6 : Effects of spacing s on te return loss as a function of frequency on te antenna structure of Fig. 1(C) From Fig. 6 we observe tat te IFDL antenna provide best return loss performance wen space from feed line s=1 mm. From overall analysis we see tat IFDL antenna provides best performance for te desired applications. Te optimized dimensions of te proposed IFDL antenna are listed in Table I. Table 1 : Optimized dimensions of te proposed antenna Antenna Name IFDLA Wideband Inverted-F Double-L Antenna for 5 Applications Antenna Values (mm) Parameters l 16 t d 2 s 1 Dimension (mm 2 ) commonly required 1 db level. Fig. 7 and Fig. 8 sow te variation of voltage standing wave ratio (VSWR) and return loss respectively. Te Peak value of return loss is -14.5, and db respectively. Te value of VSWR of IFDL antenna varies from 1.12 to 1.55 witin te operating band and obtained result indicates tat te variation of VSWR is very low and it is near to 1 as sown in Fig. 7. Fig. 9 illustrates te gain of IFDL antenna. Te peak gains of IFDL antenna is 7.6, 7.14, and 6.53 dbi wit a very small gain variation witin te 1 db return loss bandwidt at 5.2, 5.5 and 5.8 band respectively, wic indicates tat te antenna as stable gain witin te every separate operating bandwidt. VSWR Fig.7 : VSWR variation of IFDL antenna wit Fig.8 : Return loss variation of IFDL antenna wit 211 November 21 Global Journal of Researces in Engineering ( F ) Volume XI Issue VI v Version I III. NUMERICAL SIMULATION RESULTS Te IFDL antenna provides a wide impedance bandwidt of 2.5 (5-755 MHz) wic fully covers te 5.2/5.5/5.8 bands. Moreover, te IFDL antenna as te return loss appreciable tan te 211 Global Journals Inc. (US)

5 Wideband Inverted-F Double-L Antenna for 5 Applications Antenna Gain (dbi) Pase (degree) November Global Journal of Researces in Engineering ( F) Volume XI Issue VI Version I Fig.9 : Total gain variation of IFDL antenna wit Frequency. Input Impedance (Om) Fig.1 : Impedance variation of IFDL antenna wit Fig. 1 represents te antenna input impedance variation and Fig. 11 represents te antenna pase sift causes due te impedance mismatc as a function of From te obtained results, te input impedance of IFDL antenna is 69.5, and at 5.2, 5.5 and 5.8 so te input impedance of te proposed antenna is near about 5. Also, from te simulation study, te antenna offers a pase sift of , -.8 and 9.1 respectively. Terefore, pase sift of IFDL antenna closer to all over te antenna bandwidt. A comparison in gains between te proposed (IFDL antenna) and reference antennas (Inverted-F antenna) are listed in Table II. From te table it as been observed tat a significant amount of improvement resulted by IFDL antenna. A great progress experienced in return loss, VSWR, input impedance and pase. -9 Fig.11 : Pase variation of IFDL antenna wit Figs. 12 to 14 sow te normalized radiation patterns of IFDL ANTENNA at 5.2, 5.5 and 5.8 bands respectively. Normalized radiation patterns for tree resonant frequencies are sown as: total gain in Hplane and E-plane. Te antenna s normalized total radiation in E and H-plane is almost omnidirectional at te 5 WLAN and WiMAX applications. One of te significant advantages of symmetrical radiation pattern as seen from Figs. 12, 13, and 14 is tat te maximum power direction is always at te broadside direction and does not sift to different directions at different frequencies (a) (b) Fig.12 : Radiation pattern (normalized) (a) Total gain in E-plane and (b) total gain in H-plane of IFDL antenna at Fig.13 : Radiation pattern (normalized) (a) Total gain in E-plane and (b) total gain in H-plane of IFDL antenna at (a) (b) Global Journals Inc. (US)

6 Wideband Inverted-F Double-L Antenna for 5 Applications Fig.14 : Radiation pattern (normalized) (a) Total gain in E-plane and (b) total gain in H-plane of IFDL antenna at 5.8. Table 2 : Comparison between te IFDL and IF Antenna Antenna Parameter VSWR Peak Gain (dbi) Input Impedance ( ) Return Loss Pase (Degree) IV IFA CONCLUSION In tis paper we presented an Inverted-F Double-L (IFDL) antenna design. Te antenna provides a sample structure wit small area of mm2. In addition, it also ensures nearly omnidirectional radiation patterns wit incredibly ig gain 7.6, 7.14, and 6.53 dbi across te 5.2, 5.5 and 5.8 operating bands respectively. Te improvement of size, input impedance, bandwidt, gain and radiation is acieved by tis structure wic is suitable for WLAN and WiMAX applications. 18 IFDL REFERENCES RÉFÉRENCES REFERENCIAS 1. Sim C., H. Cung, and Cien Yu-Lun, 211.Compact coplanar waveguide-fed monopole antenna wit a folded ground strip for 5-gz wireless applications, Microwave and optical tecnology letters / vol. 53, no Ge, Y., K.P. Esselleand and T.S. Bird, 25. Compact diversity antenna for wireless devices, Electron.Lett., 41(2): Gao, Y., B.L. Ooi, W.B. Ewe and A.P. Popov, 26. A compact wideband ybrid dielectric resonator antenna, IEEE Microw. and Wireless Compon. Lett., 16(4): Maattanajatupat,C., P. Akkaraektalin, S. Saleekaw and M. Krairiks, 29. Bidirectional multiband antenna wit modified fractral slot fed by CPW, Progress In Electromagnetics Researc, 95: Leong, K.M.K.H., Y. Qian, T. Ito, 21. Surface wave enanced broadband planar antenna for wireless applications, IEEE Microw. and Wireless Compon. Lett., 11(2): P.T. Selvan and S. Ragaven, CPW-fed folded spiral strip monopole slot antenna for 5.8 RFID application, Electron Lett 42 (26), Augustin, G., S.V. Synu, P. Moanan, C.K. Aanandanand, K. Vasudevan, 26. Compact dualband antenna for wireless access point, Electron. Lett., 42(9): Ma, H., Q.X. Cu and Q. Zang, 28. Compact dual-band printed monopole antenna for WLAN application, Electron. Lett., 44(14): Ang, B.K. and B.K. Cung, 27. A wideband Esaped microstrip patc antenna for 5-6 wireless communications, Progress in Electromagnetics Researc, 75: Cormos, D., A. Laisne, R. Gillard, E. Le Bolzer and C. Nicolas, 23. Compact dielectric resonator antenna for WLAN applications, Electron. Lett., 39(7): G. J. Burke and A. J. Poggio, 1981.Numerical Electromagnetic Code-2. Ver , Arie Voors, November 23 Global Journal of Researces in Engineering ( F ) Volume XI Issue VI v Version I 211 Global Journals Inc. (US)