Design and Comparative Analysis of Rectangular and Square Log Periodic Array Microstrip Patch Antenna

Transcription

1 IPASJ Internatinal Jurnal f Cmputer Science (IIJCS) eb Site: ttp:// A Publiser fr Researc Mtivatin... editriijcs@ipasj.rg Vlume, Issue, December 4 ISSN Design and Cmparative Analysis f Rectangular and Square Lg Peridic Array Micrstrip Patc Antenna OGHEROHO, E. P*., Fm, T.P. And Egga, M.Y Department f Pysics, University f Js,P.M.B 84, Js Plateau State, Nigeria ABSTRACT Tis paper described te design, simulatin and cmparative analysis f inset feed seven elements lg peridic micrstrip antenna at GHz wit te aide f Agilent (ADS9).Te antennas were mdeled using micrstrip lines, te S and 3D parameters data fr bt sapes were cmpared. Te data is extracted frm te entum simulatin. Te prperties f te antennas suc as return lss, gain, iciency, pwer radiated, crss plarizatin and te beam widt ave been investigated and cmpared wit eac ter. A gain f 3.47dB using square ver te gain f.8db fr rectangular, directivity f 7.44dB t 7.9dB, iciency f 34 t 36 and resnant frequency f.75ghz and 3.35GHz respectively. Keywrds:- Square, Rectangular, Cmparative, Seven Element Inset Feed, Micrstrip.INTRODUCTION Micrstrip antenna as gain ppularity because f teir small size and ligt weigt. Hwever a limitatin f micrstrip antenna is te narrw bandwidt f te basic element. Te bandwidt f a basic patc element is usually -3%.Te bandwidt f te antenna is defined [3] as te range f frequencies, ver wic te perfrmance f te antenna wit respect t sme caracteristics cnfrms t a specific standard. Te bandwidt f te antenna depends n te patc sape, resnant frequency, dielectric cnstant and te tickness f te substrate. Te bandwidt f te antenna can be increased by reducing te substrate permittivity ( r) r increasing its tickness ().Hw ever tere are tw prblems assciated wit increasing te substrate tickness. One f te prblem is te radiatin and reactance assciated wit te feed junctin.as given by [4].Te secnd prblem is an increase in surface wave ects[3].in rder t avid te prblems, a number f different metds ave been investigated t imprve te bandwidt f te micrstrip antenna. Different tecniques t enance te bandwidt f micrstrip antenna ave been investigated. Mst f te wrk dne fr bandwidt enancement as been directed twards imprving te impedance bandwidt f te antenna element. Te bandwidt can be increased using multilayer substrate structure antenna, parasitic elements [4], nn-cntact feeding tecnique, different sapes slt [6]rt lg peridic tecnique by [7 and 4], wic we applied in tis researc.. Design f LPA Te design principle fr lg peridic requires scaling f te dimensins frm perid s tat perfrmance is peridic wit te lgaritm f frequency. Tis principle can be applied t an array f patc antennas. Te patc lengt (L), te widt () and te inset (I) are related t te scale factr τ by. Lm m I m L m m I m () If we multiply all dimensins f te array by τ its scales int itself wit element m becming element m+ element m+ becming element m+ etc. Tis self-scaling prperty implies tat te array will ave te same radiating prperties at all frequencies tat are related by a factr f τ. A single element f rectangular r square gemetry as swn in Figure, can be designed fr te lwest resnant frequency using transmissin line mdel []. f c ( L L) () Vlume Issue December 4 Page 7

2 IPASJ Internatinal Jurnal f Cmputer Science (IIJCS) eb Site: ttp:// A Publiser fr Researc Mtivatin... editriijcs@ipasj.rg Vlume, Issue, December 4 ISSN ere 8 c 3 m / s (.3) (.64) L.4 (.58) (.8) (3) r r (4) Fr micrstrip antennas te cice f te widt f te patc radiatr is very imprtant. Small values f () result in lw antenna iciencies wile large () values lead t iger rder mdes. Te ptimum values f is r (5) Te resnant input resistance can be calculated frm R in ( y y ) ( G G cs y L (6) G I sin k w cs I sin cs 3 (7) k w sin cs G j sin cs 3 k L sin d (8) j Bessel unctin f te first kind rder zer Te caracteristic impedance f te line can be calculated frm Z 8 ln w w wen 4 w (9) w w ln.444 wen w () Vlume Issue December 4 Page 8

3 IPASJ Internatinal Jurnal f Cmputer Science (IIJCS) eb Site: ttp:// A Publiser fr Researc Mtivatin... editriijcs@ipasj.rg Vlume, Issue, December 4 ISSN Te values f L, and inset feed (I) can be calculated using te abve equatins. Tis value will be scaled int lg peridic element. Calculatin f te lengt and widt f rectangular and Square patc micrstrip antenna is given in table.te substrate used is FR4 wit dielectric cnstant f 4.7 and tickness f.6.te scaling factr τ =.5.Te lss tangent f te material is.9. Table : Calculated Parameters fr Seven elements Lg Peridic Antenna Number Element f Frequency(GHz) L() () L=(Square Patc) Im f f f f f f f Te circuit design was btained using te Agilent sftware 9(ADS) te scematics were btained using te micrstrip lines (MSUB, and MTEE) and te S parameters were simulated using te abve mentined parameters. Figure and 3 sw te diagram and te layut diagram fr te Rectangular and Square patc antennas. MSub S_Param SP Start=.5 GHz Stp=3.5 GHz Step=. GHz MSUB MSub H=.6 Er=4.7 Mur= Cnd=.E+5 Hu=.e+33 T=.3 TanD=.9 Rug= S-PARAMETERS VSR VSR VSR VSR=vswr(S) N =zin(s,prtz) TL7 TL TL4 TL =7.5 =4.98 =.57 =.45 L=35.54 L=3.3 L=9.3 L=6.5 TL8 TL TL3 TL9 MSABND_MDS Bend =.5 MTEE_ADS MTEE_ADS MTEE_ADS Angle=45 TL Tee TL5 TL Tee3 TL5 TL8 Tee6 TL M=.5 MTEE_ADS MTEE_ADS MTEE_ADS TL6 TL3 TL6 Tee =.65 Tee4 =.65 Tee5 =.65 =.65 =.65 =.65 =.65 =.65 =.65 3=.5 =.65 3=.5 =.65 3=.5 =.65 =.65 =.65 3=.5 TL 3=.5 TL4 3=.5 TL7 =6.3 =3.75 =.49 L=33.78 L=3.75 L=7.85 Term Term Num= Z=5 Om Vlume Issue December 4 Page 9

4 IPASJ Internatinal Jurnal f Cmputer Science (IIJCS) eb Site: ttp:// A Publiser fr Researc Mtivatin... editriijcs@ipasj.rg Vlume, Issue, December 4 ISSN Figure : Circuit and Layut fr seven element rectangular LPA MSub S_Param SP Start=.5 GHz Stp=3.5 GHz Step=. GHz MSUB MSub H =.6 Er=4.7 Mur= C nd=.e+5 H u=.e+33 T=.3 TanD=.9 R ug= S-PARAMETERS TL7 =35.54 L=35.54 TL8 VS R VSR VSR VSR=vswr(S) N =zin(s,prtz) TL =3.3 L=3.3 TL TL4 =9.3 L=9.3 TL3 TL =6.5 L=6.5 TL9 MSABND_MDS Bend =.5 MTEE_AD S MTEE_ADS MTEE_ADS Angle=45 TL Tee TL5 TL Tee3 TL5 TL8 Tee6 TL M=.5 MTEE_ADS MTEE_ADS MTEE_ADS TL6 TL3 TL6 Tee =.65 Tee4 =.65 Tee5 =.65 =.65 =.65 =.65 =.65 L=.5 =.65 L=.5 =.65 3=.5 =.65 3=.5 =.65 3=.5 =.65 =.65 =.65 3=.5 TL 3=.5 TL4 3=.5 TL7 =33.78 =3.75 =7.85 L=33.78 L=3.75 L=7.85 Term Term Num= Z=5 Om Figure : Circuit mdeling diagram fr seven element square lg peridic antenna Figure 3: Circuit and Layut fr seven element rectangular LPA Vlume Issue December 4 Page 3

5 IPASJ Internatinal Jurnal f Cmputer Science (IIJCS) eb Site: ttp:// A Publiser fr Researc Mtivatin... editriijcs@ipasj.rg Vlume, Issue, December 4 ISSN RESULT AND DISCUSSION Te simulated results f te input and utput return lss fr te seven elements passive lg peridic antenna is swn in te figures (5-) and te cmparative values n Table : fr te cmparative f te rectangular and square array sws a real distinct difference in teir parameters. Rectangular lg peridic array Micrstrip antenna: Te bradband antenna f seven element array swn n Figure,te simulatin using ADS9 sftware package [ ],te antenna exibit a 3.99GHz resnant frequency,gain and directivity f 7.6 and 6.38dB respectively wit iciency f.89%. Square lg peridic array Micrstrip antenna: tis exibit a resnant frequency f. Figure 4: Te Return Lss fr Rectangular and Square Lg Peridic Array Micrstrip Antenna Figure 5: Te utput Return Lss f Rectangular and Square Figure 6: Smit Cart fr te input impedance Vlume Issue December 4 Page 3

6 IPASJ Internatinal Jurnal f Cmputer Science (IIJCS) eb Site: ttp:// A Publiser fr Researc Mtivatin... editriijcs@ipasj.rg Vlume, Issue, December 4 ISSN Figure 7: Te radiatin Pattern fr Rectangular and Square LPA Figure 8: Te E-c and E-crss f Rectangular and Square LPA Figure 9: Te 3D radiatin pattern fr rectangular and Square LPA Vlume Issue December 4 Page 3

7 IPASJ Internatinal Jurnal f Cmputer Science (IIJCS) eb Site: ttp:// A Publiser fr Researc Mtivatin... editriijcs@ipasj.rg Vlume, Issue, December 4 ISSN Percentage m5 THETA= -5. real(efficiency)=.38 Max m5 Percentage m9 THETA= 4. real(efficiency)=.764 Max m THETA THETA Figure : Efficiency fr Rectangular and Square LPA Table : Te Antenna Parameters fr Rectangular and Square Array 3.CONCLUSION Te seven elements lg peridic rectangular and square array as been designed and analyzed using Agilent electrmagnetic simulatr. Te results sw a little difference frm teir perfrmances in terms f resnating frequency.75ghz and 3.35GHz respectively,gain f.8db and 3.47dB wic is ig cmpare t tat f rectangular and directivity as well as pwer radiated, but wit 5% bandwidt and are bt icient in perfrmance. It can be deduced tat eac sape is apprpriate fr different purpses f wireless cunicatin applicatin. References [] Balanis, C.A., Antenna Tery Analysis and Design nd editin, jn illey & Sns Inc. New Yrk, 997. [] Cen H.M, Sze, J.Y, Lin, Y.F., A Bradband rectangular micrstrip Antenna wit a pair f U saped slts Micrwave and Optical tec.letters, Vl.7, n.5, Dec., pp [3] Grag, P.Bartia, P., I. Bal and A. Itlipibn..Micrstrip Antenna Design Handbk. Artec Huse Inc. Nrwd, USA. [4] Raim, M.K.A and Gardner, P. Te Design f Nine Elements Quasi Micrstrip Lg Peridic Antenna RF and Micrwave Cnference, Oct.4. [5] Hall, P.S., Multictave bandwidt Lg peridic Micrstrip Antenna Array IEE prc.vl.33pt H N..986.pp7-36. Vlume Issue December 4 Page 33