Intenational Jounal of Engineeing and Advanced Technology (IJEAT) ISSN: 49 8958, Volume-7 Issue-5, June 08 Hexagonal Shaped Micostip Patch Antenna fo Satellite and Militay Applications Jayaenjini N, Unni C Abstact: In this wok, investigation of the effect of diffeent slots in a hexagonal shaped micostip patch antenna is pesented. The poposed antenna is designed on FR4-epoxy substate and the pefomance is obtained by using CST Micowave Studio. The antenna has been analyzed fo vaious dimensions of slots and the optimum design has been chosen. By inceasing the numbe of slots, the gain, bandwidth and etun loss of the stuctue has been impoved. The simulated antenna stuctues also show dual band chaacteistics. The antenna offes application in WiFi IEEE80.n (.4 to 5 GHz) and UWB ange especially fo X-band uplink satellite system (7.9 8.4GHz). As the designed stuctues esonate in C-band (4-8 GHz), it offes applications in Fixed Satellite Sevices (FSS) and militay also. Index Tems: Micostip Patch Antenna, Ulta Wide Band, Fixed Satellite Sevices, Retun Loss. I. INTRODUCTION As the demands of wieless systems have inceased day by day, low pofile systems have dawn the inteest of the eseaches towads the Micostip Patch Antennas []. The gowing wieless communication systems equie small size and compact antennas which have wide bandwidth than conventional antenna design []. In the design of communication systems of low-pofile, size of antenna is a most citical facto. Theefoe, miniatuization techniques ae used fo the design of diffeent kinds of antennas []. Multiband antennas povide an effective integation of seveal communication standads, in addition to low-cost and high data ate featues. Multiband antennas can be designed by feeding techniques [ 3], etching slots [4 6], adding multi-banched stips, factals etc. Slots ceate some sot of discontinuity in the electic cuent path leading to positive impact on input impedance theeby ceating additional esonance fequencies. Reseach shows that cutting slots and slits in adiating patch and gound plane [8-] shift the opeating fequency and incease esonating fequencies. The poposed antenna woks in the WiFi IEEE80.n (.4 to 5 GHz) and UWB ange especially fo X-band uplink satellite system (7.9 8.4GHz). This stuctue can also be used fo C-band (4-8 GHz) applications in Satellite communication and also fo medical uses to detect cances and tumos whee the safe fequency ange fo human tissues is 4 GHz - 9.5 GHz. A small-size hexagonal patch antenna is made using Revised Manuscipt Received on 7 June 08. Jayaenjini N, Asst. Pofesso, Depatment of Electonics and Communication Engineeing, ACE College of Engineeing, Tivandum, Keala, India. E-mail: jayaenj@gmail.com Unni C, Pofesso, Depatment of Electonics and Communication Engineeing, TKM College of Engineeing, Kollam, Keala, India. E-mail: unnic6@gmail.com cicula slots. By inceasing the numbe of slots and deceasing the size of the slots, we can obseve that the gain of the poposed antenna has been inceased. The pape is divided into thee moe sections. Section II shows the antenna design, Section III shows the paametic study of hexagonal patch antenna and Section IV shows the paametic study of poposed antenna. A compaative study of hexagonal patch antenna with the poposed antenna with slots is discussed in Section V. II. ANTENNA DESIGN The micostip antenna consists of a vey thin patch placed above a gound plane. The patch can be of any shapes such as ectangula, cicula, tiangula. In this wok, the hexagonal patch with slots is selected fo the analysis. Although the tansmission line model yields less accuate esults, it is a vey simple model and povides a good physical insight of the basic antenna pefomance. Among the vaious feeding methods, micostip line feed is chose as it is simple to model and easy to fabicate. A. Design of Rectangula Patch The model of Micostip Antenna can be epesented by two slots of width (W) and height (h) sepaated by tansmission line of length (L). The width of the patch can be calculated fom the following equation [7]. v W 0 f The effective dielectic constant of the substate can be calculated as follows, () eff h W The actual length of the antenna is diffeent fom the calculated L since the finging field also needs to be consideed hee. The actual length is calculated by subtacting the excess lengths fom both the sides of the patch. The length of the Patch Antenna L is given by, W eff 0.3 0.64 c h (3) L 0.84h f W eff eff 0.58 0.8 h Highe values of pemittivity allow a shinking of the Patch Antenna. Paticulaly in cell phones, the designes ae given vey little space and want the antenna to be a half-wavelength long. One technique is to use a substate with a vey high pemittivity. () Retieval Numbe: E5406758 0 Blue Eyes Intelligence Engineeing
Hexagonal Shaped Micostip Patch Antenna fo Satellite and Militay Applications The actual length of the Patch Antenna is given by, c L L f eff The length (Lg) and the width (Wg) of a gound plane ae calculated using the following equations, (4) Lg=6h+L and Wg = 6h + W (5) Hence, if the pemittivity is inceased by a facto of 4, the length equied deceases by a facto of. Using highe values fo pemittivity is fequently exploited in antenna miniatuization. The height of the substate h also contols the bandwidth - inceasing the height inceases the bandwidth. B. Design of Hexagonal Patch The aim is to design a patch shape othe than ectangle; a ectangula patch fo the paticula fequency is designed initially. The paametes of ectangula patch ae modified to obtain the dimensions of the othe patch shapes like cicula, hexagonal etc. The adius a of a cicula patch whose esonant fequency is f is given by, X mnc a (6) f Xmn =.8 fo T M mode The effective adius of the patch can be calculated as, h a a a ln.776 (7) e a h If the patch is hexagonal, then the sides of the hexagon can be calculated using the effective adius of the cicula patch. The side of the hexagonal patch S is given by, C. Design Specifications S e a (8) 3 3 All of the paametes in a Rectangula Patch Antenna design (L, W, h, pemittivity) contol the popeties of the antenna. Table I gives the design specifications of the standad ectangula patch and hexagonal patch. Table I. Design Specifications of Patch Substate mateial used Thickness between gound and fed patch (h) Length of the ectangula patch (L) Width of ectangula patch (W) FR4 (ε=4.3).6 mm 9.698 mm 3.63 mm The pefomance paametes such as etun loss, bandwidth and adiation pattens of the hexagonal antenna ae discussed below. The basic stuctue is that of a Hexagonal Patch Antenna shown in Fig... Retun Loss Fig.. Hexagonal Patch Antenna The esponse S (, ) shows in Fig. and the antenna esonates at 7.38 GHz with a Retun Loss of -4.6 db. The antenna has a bandwidth of 0.70 GHz. The aea of hexagonal patch is 99.47 mm.sq. Fig.. Plot of S Paametes vesus Fequency. Radiation Patten The Radiation popety of any antenna can be analyzed to undestand the distibution of powe aound the oientation. The simulated gain patten of the antenna can be studied at vaious esonant fequencies. Radius of the cicula patch (a) Width of the gound plane (Wg) The length of the gound plane (Lg) The side of the Hexagonal Patch (S) 6.056 mm.763 mm. 9.98 mm. 6.0 mm III. PARAMETRIC STUDY OF HEXAGONAL ANTENNA Thee ae vaious paametes, which can be used to tune the antenna. The majo among them ae the slot length, slot width, feed line width and position of the patch elative to the slot. Fig.3. Radiation Pattens at 7.38 GHz Retieval Numbe: E5406758 0 Blue Eyes Intelligence Engineeing
Intenational Jounal of Engineeing and Advanced Technology (IJEAT) ISSN: 49 8958, Volume-7 Issue-5, June 08 The Radiation patten of the antenna shows (Fig. 3) that the antenna has a gain of 4.93 dbi. IV. PARAMETRIC STUDY OF PROPOSED ANTENNA The pefomance paametes such as etun loss, bandwidth and adiation pattens of the poposed antennas ae discussed below. In slotted hexagon antennas, a basic hexagon is designed at 7.38 GHz. Diffeent kinds of slots ae incopoated in the patch and the esults ae studied. A. Stuctue The basic stuctue is that of a Hexagonal Patch Antenna. Cicula slots wee incopoated in the antenna and ae shown in Fig.4. A lage cicula slot of diamete mm was ceated in the cente of the patch. Fou smalle cicles of diamete 0.5 mm wee also geneated aound the cental slot. Fig.7. Radiation Pattens at 7.98 GHz The Radiation pattens of the antennas at both the fequencies ae as shown in Fig.6 and Fig.7. The gain at 4.8 GHz is 6.39 dbi and the gain at 7.98 GHz is 4.69 db. The aea of the patch is 83.76 mm.sq. The impovement in bandwidth when compaed to basic hexagonal patch at 4.8 GHz and 7.98 GHz ae -44. % and 5. % espectively. The eduction in aea of the patch when compaed to basic patch is 8%. B. Stuctue The lage cicula stuctue at the cente is of diamete mm and twelve smalle cicula stuctues of diamete mm ae placed aound the lage cicle as shown in Fig.8.. Retun Loss Fig.4. Stuctue The esponse S (, ) shows in Fig.5, that antenna esonates at two diffeent fequencies. The antenna povided a etun loss of -.66 db at 4.8 GHz with a bandwidth of 0.48633 GHz. At 7.98 GHz, the antenna adiated with a etun loss of -9.3 db and a bandwidth of 0.863 GHz.. Retun Loss. Fig.8. Stuctue The esponse S (, ) shows in Fig.9, that antenna esonates at two diffeent fequencies. The antenna povided a etun Loss of -.69 db at 4.8 GHz with a bandwidth of 0.5 GHz. The antenna also esonates at 7.9 GHz with a Retun Loss of -9.7 db and a bandwidth of 0.795 GHz. Fig.5. Plot of S Paametes vesus Fequency. Radiation Patten The Radiation popety of any antenna can be analyzed to undestand the distibution of powe aound the oientation. The simulated gain patten of the antenna can be studied at vaious esonant fequencies. Fig.9. Plot of S Paametes vesus Fequency Fig.6. Radiation Pattens at 4.8 GHz Retieval Numbe: E5406758 03 Blue Eyes Intelligence Engineeing
Hexagonal Shaped Micostip Patch Antenna fo Satellite and Militay Applications. Radiation Patten The Radiation popety of any antenna can be analyzed to undestand the distibution of powe aound the oientation. The simulated gain patten of the antenna can be studied at vaious esonant fequencies. Fig.0. Radiation Pattens at 4.8 GHz Fig.. Radiation Pattens at 7.9 GHz The Radiation pattens of the antennas at both the fequencies ae as shown in Fig.7 and Fig.8. The gain at 4.8 GHz is 7.09 dbi and the gain at 7.9 GHz is 6.37 dbi. The impovement in bandwidth when compaed to the basic hexagonal patch is -34.5 % at 4.8 GHz and is.83 % at 7.9 GHz. The aea of the patch is 6.7 mm. sq. The eduction in aea when compaed to the simple hexagonal patch is 6. %. V. COMPARATIVE STUDY Table II shows the compaison of conventional hexagonal patch antenna and the hexagonal patch antenna with slots in tems of opeating fequency, etun loss, gain and bandwidth. Hexago nal Patch Antenn a Table II. Compaison of Antenna Paametes Resonating Fequency (GHz) Retun Loss (db) Band width (GHz) Aea (mm.s q.) Gain (dbi) 7.38-4.6 0.70 99.47 4.93 Hexagonal Patch Antenna with slots Stuctue Stuctue 4.8 -.6 0.486 6.39 83.76 7.98-9. 0.86 4.69 4.8 -.69 0.5 7.09 6.7 7.9-9. 0.795 6.37 The poposed Hexagonal Patch Antenna with slots shows multiband behavio chaacteistics with impoved bandwidth. By inceasing the slots, the gain of the antenna is also impoved and eduction in aea is also achieved. VI. CONCLUSION In this wok, the poposed antenna woks in the WiFi IEEE80.n (.4 to 5 GHz) and UWB ange especially fo X-band uplink satellite system (7.9 8.4GHz) applications. The designed antenna stuctues can also be used fo C-band (4-8 GHz) applications in Satellite communication and also fo medical uses to detect cances and tumos whee the safe fequency ange fo human tissues is 4 GHz - 9.5 GHz. By intoducing slots in standad hexagonal patch antenna, it is obseved that the gain and the bandwidth have been impoved. The poposed stuctue shows dual band chaacteistics with a lowe value of etun loss. Fom the analysis, it is obseved that intoduction of slots ceate some sot of discontinuity in the electic cuent path leading to positive impact on input impedance theeby ceating additional esonance fequencies. In Stuctue, the impovement in bandwidth when compaed to basic hexagonal patch at 4.8 GHz and 7.98 GHz ae -44. % and 5. % espectively. The eduction in aea of the patch when compaed to basic patch is 8%. In Stuctue, the impovement in bandwidth when compaed to the basic hexagonal patch is -34.5 % at 4.8 GHz and is.83 % at 7.9 GHz. The aea of the patch is 6.7 mm. sq. The eduction in aea when compaed to the simple hexagonal patch is 6. %. REFERENCES. C.Y. Liu, 0, An Impoved Rectenna fo wieless Powe Tansmission fo Unmanned ai vehicles, naval postgaduate School, Monteey, Califonia.. R. Yogamathi, S. Banu, A. Vishwapiya, Design of factal antenna fo multiband applications, IEEE-366, ICCCNT, 4-6 July, 03. 3. Chung K, Kim J, Choi J. Wideband micostip-fed monopole antenna having fequency band-notch function. IEEE Micowave Wiel. Compon. Lett. 005;5:766 768. 4. Vuong TP, Ghiotto A, Duoc Y, Tedjini S. Design and chaacteistics of a small U-slotted plana antenna fo R-UWB. Micowave Opt. Technol. Lett. 007;49:77 73. 5. Abbosh AM, Bialkowoski ME, Mazieska J, Jacob MV. A plana UWB antenna with signal ejection capability in the 4 6 Hz band. IEEE Micowave Wiel. Compon. Lett. 006;6:78 80. 6. Kim Y, Kwon DH. CPW-fed plana ulta wideband antenna having a fequency band notch function. Electonics Lett. 004;40:403 405. 7. Loena I. Basilio. 00. The Dependence of the Input Impedance on Feed Position of Pobe and Micostip Line-Fed patch Antennas. IEEE Tansaction on Antennas and Popagation. 49( ) 8. Jayaenjini N, Ali Fathima N A, Megha S and Unni C, Dual polaized Micostip Factal patch antenna fo S-band Applications, IEEE Confeence Publications in Contol, Communication and Computing, 05. Digital Object Identifie: 0.09/ICCC.05.74394 9. Symposium, Vol.,pp. 704-707,June. [4] Wong, K. (00), "Com pact and Boadband Micostip Antenna", JohnWiley & Sons,Inc. 0. Kam tongdee, C. and Wongkasem, N. (009), "A Novel Design of Compcat.4 GHz Micostip Antennas", 6. Intenational Coifence ECTI-CON, Vol.,pp. 766-769,May. Gupta,N. and Gupta,V.R. (005),"Reduced Size,Dual Fequency Band Antenna fo Wieless Communication",IEEE Intenational Coifence on Pesonal Wieless Communications, pp. 3-33,Jan.. Ghosh,B.,Haque,S.M. and Mita,D. (0), "Minituaization of Slot Antennas Using Slit and Stip Loading",IEEE Tansactions on Antennas and Popagation, Vol. 59,pp. 39-397,Aug. Retieval Numbe: E5406758 04 Blue Eyes Intelligence Engineeing
Intenational Jounal of Engineeing and Advanced Technology (IJEAT) ISSN: 49 8958, Volume-7 Issue-5, June 08 3. R. J. Vidma. (99, August). On the use of atmospheic plasmas as electomagnetic eflectos. IEEE Tans. Plasma Sci. [Online]. (3). pp.876 880. Jayenjini N eceived B.Tech Degee in Electonics and Communication Engineeing fom Kannu Univesity, Keala, India in 003 and M.Tech Degee fom Univesity of Keala, Keala, India in 006. She is cuently woking towad the Ph.D. degee fom Univesity of Keala, Keala, India. She is cuently woking as Assistant Pofesso in Electonics and Communication Engineeing, ACE College of Engineeing, Tivandum, Keala, India. He eseach inteest includes design of UWB antennas, RFID antennas, Micostip Patch Antennas, Factal Antennas. D. Unni C eceived the B.Sc. Degee, M.Tech Degee and Ph.D. Degee in in Electonics and Communication Engineeing fom Univesity of Keala, Keala, India. He has been with the Depatment of Electonics and Communication Engineeing, TKM College of Engineeing, Kollam, Keala, India since 985, whee he is cuently a Pofesso. His eseach inteest includes Nano mateials and devices, Micowave antennas fo Wieless Communication and Photonic Systems. Retieval Numbe: E5406758 05 Blue Eyes Intelligence Engineeing