Modified Compact High Gain Multiple Patch Slotted Microstrip Antenna for Multiband Wireless Applications

Transcription

1 Intenational Jounal of Scientific & Engineeing Reseach Volume 2, Issue 7, July Modified Compact High Gain Multiple Patch Slotted Micostip Antenna fo Multiband Wieless Applications A. Beno, D.D.S. Emmanuel, T. Sindhuja, K. Packia Lakshmi Abstact A modified appoach fo the design of a compact multi-element patch antenna which opeates in pentaband is poposed. The antenna compises of a main patch with subpatches containing esonating slots. The main patch is fed with a 50Ω micostip line. The antenna opeates with multiple opeational fequencies coveing the bands fom 1.9GHz to 9.5GHz with good impedance matching. The design is veified using simulation softwae ANSOFT HFSS and tested using the laboatoy expeimental appoach which esembles the simulated output with an omnidiectional adiation chaacteistics.the multipatch antenna achieved a Peak Gain of db at 8.38 GHz and stays above 2.42 db though the entie opeating band. The fequency of opeation is suitable fo wieless devices suppoting multiple standads including Univesal Mobile telecommunication System (UMTS, MHz), Wieless Local Aea Netwok (WLAN, MHz) and low band Woldwide Inteopeability fo Micowave Access (WIMAX, 2.5 to 2.8 GHz). Index Tems ANSOFT HFSS, Compact, High Gain Micostip feed, Multi-element Patch, Omni diectional, Slotted Patch, Wieless Applications. 1 INTRODUCTION I N today s moden communication industy, antennas ae the most impotant components equied to ceate a communication link. Micostip patch antennas ae inceasingly used stuctue in vaious wieless applications fields [1], because of thei low pofile, light weight and low powe handling capacity [2]. They can be designed in a vaiety of shapes in ode to obtain enhanced gain and bandwidth fo multiband fequency application independent of the opeating fequency [3]. The concept of miniatuization is widely used in the pesent technological developement aena to minimize the effective electical length of the antenna opeatable at lowe fequencies. Seveal methodologies wee adapted to miniatuize a patch antenna [4]. Electomagnetic bandgap (EBG) stuctue is used as defected gound plane stuctue to educe size and achieve multiband esonant fequencies [5]. To have multiple esonant fequencies one of the methods implemented is using slots on the adiating patch [6]. Many novel stuctues like Tapeed Slot, Squae Slot, U-Slot, T-Slot, V-Slot and many othe shapes and stuctues wee used by eseaches epoted in liteatues [7], [8], [9]. The opeating fequency chaacteistics obtained depend on the shape and position of the slots and also detemine the ulta wideband chaacteis A. Beno, Reseach Schola, VIT Univesity and woking in Depatment of ECE, D.Sivanthi Aditana College of Engineeing, Tiuchendu, India, PH beno_csi@yahoo.com D.D.S. Emmanuel is with the School of Electonics Engg. Velloe Institute of Technology, Velloe, India. dsemmanuel@vit.ac.in T. Sindhuja, Depatment of ECE, D.Sivanthi Aditana College of Engg., Tiuchendu, India. sindhuengg2006@gmail.com K. Packia Lakshmi has completed UG in ECE fom D.SACOE -tics of the antenna [10]. When the slot is geneated on the adiating patch element the cuents and the excited mode is petubed which helps to educe the effective designed esonant fequency towads achieving miniatuization. Anothe technique to obtain the multiband fequency is meandeing the patch. Meandeing is achieved by inseting seveal naow slits at the patch elements non adiating edges. The excited patch adiating elements suface cuent is effectively meandeed leading to a geatly lengthened cuent path fo a fixed patch linea dimension. This behavio esults in a geatly loweed antenna fundamental esonant fequency and thus a lage antenna size eduction at a fixed opeating fequency is achieved [11]. The micostip antenna with dual, tiple and quad band antennas ae epoted fo the applications of mobile wielss applications. Similaly multielement antennas with multiband opeational capabilities wee poposed to suit the vaious equiements of the wieless application demand. Antennas opeated in moe than a band and extend ove a wideband suffes gain ove the entie band of opeation. A multielement antenna fo multiband antenna is poposed with modifications in the antenna slots available with the stuctue poposed as in [12]. The antenna is designed to attain high gain by adding up the benefits of the sub-patcges connected with the main patch and making the antenna to opeate in the specific wieless bands. Antenna with multiple elements and multiband applications ae epoted in liteatue as in [13]. A simple compact antenna is designed to cove five opeating fequency bands usable fo vaiety of communication appli

2 Intenational Jounal of Scientific & Engineeing Reseach Volume 2, Issue 7, July cations speading in the fequency ange fom 1.9GHz to 9.5GHz. 2 RECTANGULAR MICROSTRIP PATCH ANTENNA Micostip patch antenna in its basic fom consists of a adiating patch on one side of a dielectic substate which has a gound plane on the othe side as shown in Fig1. Patch Width, W = (1) Patch Length, L= L eff 2dL (2) C Whee Leff (3) 2 f dl 0.412h W 0.3 h W h (4) Fig. 1. Micostip Line Feed h W 1 2 (5) The patch is geneally made of conducting mateial such as coppe o gold and can take any possible shape. The adiation patten is dependent on the patch. Micostip patch antennas adiate pimaily because of the finging fields between the patch edge and the gound plane. The adiating patch and the feed lines ae usually photo etched on the dielectic substate. In ode to simplify analysis and pefomance pediction, the patch is geneally squae, ectangula, cicula, tiangula, elliptical o some othe common shape. Micostip patch antennas can be fed by a vaiety of methods. The fou most popula feed techniques used ae the micostip line, coaxial pobe, apetue coupling and poximity coupling.the micostip line feed is used. In this type of feed technique, a conducting stip is connected diectly to the edge of the micostip patch as shown in Fig2. The conducting stip is smalle in width as compaed to the patch and this kind of feed aangement has the advantage that the feed can be etched on the same substate to povide a plana stuctue. Hence this is an easy feeding scheme, as it povides ease of fabication and simplicity in modeling. 2.1 Design Paametes The basic design consideations fo a ectangula patch wee consideed fo the design. The length L of the patch is usually λo < L < 0.5λo, whee λo is the feespace wavelength. The patch is selected to be vey thin such that t << λo (whee t is the patch thickness). The height h of the dielectic substate is usually 0.003λo h 0.05λo. The dielectic constant of the substate (ε ) is typically in the ange 2.2 ε 12. Fomulas used fo the patch design is given below, Gound Length, L g = 6h+L (6) Gound Width, Wg = 6h+W (7) Substate height is h and Substate mateial choosen is FR Design Paamete Values The design fomulae wee used to detemine the antenna dimension paametes. This antenna is designed with the TABLE 1 DIMENSIONS OF ANTENNA consideation of a main patch connected with fou subpatches to attain the multiband opeation chaacteistics. The detailed paametes attained fo the design ae shown in Table 1. 2 f c 1 2

3 Intenational Jounal of Scientific & Engineeing Reseach Volume 2, Issue 7, July ANTENNA DESIGN 3.1 Antenna Physical Stuctue The dimensional paametes ae estimated fo the multiband antenna design and shown in Table 1. The antenna stuctue consists of a main patch connected to fou sub patches. The fou connected sub-patches ae designed with slots of vaious shapes to attain the desied opeational bands. The intoduction of a slot altes the opeational fequency of the adiating stuctue to attain miniatuization [14], [15]. to opeate effectively in the five bands with educed bandwidths in two of its opeating bands. 4 EXPERIMENTAL RESULTS The antenna stuctue is fabicated and tested using a simple expeimental setup in the laboatoy. The expeimental set up consists of C-Band and X-Band souces connected with micostip taine modules compising of a Diectional Couple, Test Jig, detecto unit and suitable R.F connectos with motoized adiation patten monitoing units to ecod the adiation patten of the antenna. Fig. 2. Cougated MSA Design Stuctue with fou slots The sub-patch1 and sub-patch 4 is designed with a cicula slot. The sub-patch 2 is intoduced with a ectangula slot and the sub-patch 4 is inseted with a T-shaped slot with a pécised dimension to attain the equied opeating band. The stuctue of the antenna is shown in Fig 3. The adiating patch is fabicated on a FR4 substate with pemittivity ε = 4.4. The adiating patch is placed above the gound ove the substate with the height of h = 2.4mm.The height of the substate is inceased to attain bette miniatuization chaacteistics. The antenna stuctue is designed, constucted and simulated using simulation softwae ANSOFT HFSS. The simulation etun loss against fequency chaacteistics esult of the antenna is shown in Table II. The antenna is fed with a micostip line matched to the adiating patches. The position of the micostipline feed is optimized by changing the feed location and obseved good esponses at feed locations at 56mm, 39mm (x,y) with feed length of 2.4mm and feed width of 3mm whee it offeed good impedance matching. The antenna exhibited good impedance matching in five bands with cente fequencies of the bands 1.89 GHz, 5.73 GHz, 7.66 GHz, 8.40 GHz and 9.74GHz. The coesponding etun loss and bandwidth ae shown in Table II. The obtained etun loss shows the ability of the antenna Fig. 3. Fabicated MSA Design Testing Method The antenna is connected with the test jig unit using the diectional couple to obseve the etun loss chaacteistics in the specific bands of opeation. The etun loss matched with the simulation esults in the tested bands. The antennas ae then tested in the fee space envionment connected with the adiation patten monitoing and ecoding unit which also esulted in a good adiation chaacteistics simila to the simulated adiation chaacteistics. The 3-D adiation chaacteistics shows good diectional chaacteistics of the antenna with a gain of db. The adiation chaacteistics exhibits good font to back adiation chaacteistics as the gound plane helps to educe the back adiation. The adiation suffeed minimum sidelobe level with boad beamwidth suitable fo wieless applications. The adiation chaacteistics show the diectivity of the antenna eaching a value of db. 4.1 Simulation Result The Retun loss against fequency chaacteistics of the poposed antenna is simulated using Ansoft HFSS and it

4 Intenational Jounal of Scientific & Engineeing Reseach Volume 2, Issue 7, July is shown in Fig 4. The chaacteistics povides good impedance matching at five bands with opeating fequencies centeed at 1.89 GHz, 5.73 GHz, 7.66 GHz,8.40 GHz, 9.74 GHz with etun loss values less than -10dB and thei espective bandwidth in Table 2. The diectivity of the antenna adiation is obseved and esulted as db with omni diectional chaacteistics. The adiation makes the antenna moe suitable fo the pesent day wieless communication which equies boad beam coveage in a specific diection to povide the equied coveage aea with minimum antennas. Fig. 6.Diectivity Fig. 4. Fequency vs Retun loss TABLE 2 RETURN LOSS CHARACTERISTICS The 2-D pola plots fo the E-Field and H-field ae shown in the Fig. 7 a) and Fig. 7 b). The E-field patten gives a wide beam with mino back adiation. The main lobe magnitude has eached moe than 2.01 db. 4.2 Radiation Patten The adiation patten of the antenna is simulated and tested in fee space envionment using automatic system inteface adiation patten plot geneato unit. The tested esults esembled the simulated esults. The 3-D adiation plot of the antenna is shown in Fig. 5, which shows the peak gain achieved by the antenna in the fa field egion. Fig. 7.a). E-Field patten, b). H-Field patten The test is pefomed fo all the bands of fequencies and a fequency against the Gain plot is attained as shown in Fig. 8. The gaph shows the antenna achieving a peak Gain of db at 8.37 GHz. Miniatuized antenna suffes fom poo gain chaacteistics and equie added cicuits o devices to boost up the signals. This compact antenna achieved a high gain in almost all the bands of opeation and makes it an attactive candidate fo lots of communication applications as it has the capability to pick vey weak signals and can adiate effectively into the fa field ove lage distance when compaed to miniatuized antennas.

5 Intenational Jounal of Scientific & Engineeing Reseach Volume 2, Issue 7, July CONCLUSION The antenna is designed successfully, simulated and tested with simple expeimental appoach to study the multiband antenna. The antenna coves the opeating fequency band fom 1.89GHz to 9.74GHz with good etun loss chaacteistics. The esult shows in two of the opeating bands the antenna suffeed in bandwidth pefomance which can be futhe optimized to impove. The antenna exhibited good impedance matching in all the opeating bands and attained a peak gain of db. The adiation chaacteistics esulted with a diectivity of db without sidelobes and possess boad beamwidth to povide good coveage in desied diections fo communication applications. The attained bands of opeation make the antenna most suitable fo applications such as UMTS, WLAN, WIMAX communications. ACKNOWLEDGMENT The Fist autho is gateful to D. D.S Emmanuel fo motivating and guiding in the pogess of his eseach degee. Also expess his sincee thanks to the Management of VIT Univesity, Velloe and D.Sivanthi Aditana College of Engineeing, Tiuchendu. REFERENCES Fig. 8. Fequency vs Gain. [1] Bedi A. Cetine, Fanco De Flaviis, and Luis Jofe, Miniatue Multi-Element Antenna fo Wieless Communications, IEEE Tansactions On Antennas And Popagation, Vol. 50, No. 5, May [2] Gag, R, Bhatia, P., Bahl, I., and Ittipiboon, A, Micostip Antenna Design Handbook, Atech House, London, [3] Kin-Lu Wong, Compact and Boadband Micostip Antennas, John wiley & sons, wiley-intescience publication. [4] N. Behdad and K. Saabandi "Bandwidth enhancement and futhe size eduction of a class of miniatuized slot antennas", IEEE Tans. Antennas Popag., vol. 52, pp [5] Riku Ma Kinen, Vesa Pyntta Ri, Jouko Keikkinen, And Makku Kivikoski Impovement of Antenna Isolation In Handheld Devices Using Miniatuized Electomagenteic Band Gap Stuctues," Micowave and Optical Technology Lettes Vol.49, No. 10, Pages , Octobe [6] Nade Behdad, Mak Schambege, Nicholas E. Buis, Slot Antenna Design fo Wieless Communications Systems, Univesity of Cental Floida, Olando, FL 32816, U.S.A. [7] Amin M. Abbosh, Miniatuized Micostip-Fed Tapeed-Slot Antenna With Ultawideband Pefomance, IEEE Antennas And Wieless Popagation Lettes, VOL. 8, [8] Eldek, A. A., A. Z. Elshebeni, and C. E. Smith, Squae slot antenna fo dual wideband wieless communication systems," Jounal of Electomagnetic Waves and Applications, Vol. 19, No. 12, , [9] Wang Ren, Zhiguo Shi,Yu Li,and Kangsheng Chen Compact Dual- Band T-Slot Antenna fo 2.4/5 GHz Wieless Applications, pages , 2006 IEEE. [10] Amit A. Deshmukh and K. P. Ray, Compact Boadband Slotted Rectangula Micostip Antenna, IEEE Antennas And Wieless Popagation Lettes,VOL.8,2009. [11] Haiwen Liu, Shohei Ishikawa, An An, Satoshi Kuachi, and Toshihiko Yoshimasu, Miniatuized Micostip Meande-line Antenna with vey high-pemittivity substate fo Senso applications, Micowave And Optical Technology Lettes, Vol. 49, No. 10, Octobe [12] H.S. Al- Raweshidy, M. J. Alexande, D. Budimi, R. Nilavalan, K. M. Nas and H. F. A. Taboush A Compact Pinted Antenna fo Multiband Wieless Applications, in IEEE,2010. [13] Dalia Nashaat, Hala A. Elsadek, Esmat Abdallah,Hadia Elhenawy and Magdy F.Iskande, Multiband and Miniatuized Inset Feed Micostip Patch Antenna Using Multiple Spial- Shaped Defect Gound Stuctue (DGS), PIERS Poceedings, Moscow, Russia, August 18-21, [14] M. F Abdul Kadi, M. Z. A. Abdul Aziz, M.R. Che Rose, M. S. R. Mohd Shah, D. Misman, M. K Suaidi, Dual Polaization Inset-Fed Micostip Patch Antenna, Asia-Pacific confeence on electomagnetic poceeding [15] Md. Fokhul Islam, M. A. Mohd. Ali, B. Y. Majlis and N. Misan, Design, Simulation and Fabication of a Micostip Patch Antenna fo Dual Band Application, 5th Intenational Confeence on Electical and Compute Engineeing ICECE 2008, Decembe 2008, Dhaka, Bangladesh.