Comparative Study on Different Dual-Band HIS Structures

Transcription

1 ISSN (Print) : International Journal of Advanced Researc in Electrical, (An ISO 3297: 27 Certified Organization) Vol. 4, Issue 1, January 215 Comparative Study on Different Dual-Band HIS Structures H. adie Badri 1, H. Zairi 2, A. Garsalla 3 PD Student, Dept. of Pysics, Faculty of Sciences of Tunis, Tunis, Tunisia 1 Assistant Professor, Dept of EE, ESTI, Tunis, Tunisia 2 Full Professor, Dept. of Pysics, Faculty of Sciences of Tunis, Tunis, Tunisia 3 ABSTRACT In tis paper, we present a comparative study of two different dual-and ig impedance surfaces (HIS) to e used as ground planes. Tese structures are designed to eave as a magnetic conductor surface for gloal positioning system (GPS) standard frequencies 1 (1575 MHz) and 2 (1227 MHz). Eac of te two surfaces is caracterized y performing parametric studies of its unit cell. Te studies were carried out using CST Microwave Studio Simulation software. Te results sow tat te two-layer cell gives te est andwidt for ig and low frequency ands. KEYORDS: EBG, Dual-and-HIS, Reflection pase. I. INTRODUCTION Microstrip antennas are widely used in a variety of areas, suc as wireless communication systems, RFID, satellite communications and GPS systems [1-2]. But tese antennas usually ave idirectional radiation pattern and low gain [2]. In order to acieve directional radiation caracteristics, tey need to e integrated wit a reflector. However, for dual-and antennas it is difficult to realize well matced directional caracteristics over ot working frequencies wen using a conventional metallic reflector. In tis context, HIS ave een introduced like reflectors to improve antennas profile. Te comination of a dual-and ig-impedance surface reflector and te antenna provides directional properties for ot frequency ands [3]. Te ig-impedance surface (HIS) is a king of electromagnetic and gap (EBG) material tat as te property of magnetic conductor surface witin its and gap frequencies [4]. Over te past decade, ig-impedance surfaces are widely used in microwave and antenna engineering for teir aility to realize relatively low-profile, ig-gain and ig-efficiency antenna in close proximity to metallic surfaces [5]. Various kinds of HIS structures ave een proposed and investigated [6-7-8]. Tis study focuses on dual-and HIS structures. In tis paper, we present a comparative study of two different dual-and HIS structures tat can e used as HIS reflector for dual-and antenna wic is working at 1 and 2 GPS frequencies of GHz and GHz. Te first structure is composed of one layer wile te second is composed of two layers. Terefore, te present paper is divided into four main parts. First of all, section I presents te introduction. Besides, section II igligts te design and te parametric studies of te dual-and HIS structures. Ten, section III focuses on a comparative study of te structures and finally section IV presents te conclusion and recommendations for furter studies. II. DUA-BAND HIS STRUCTURES Considering te usefulness of HIS as ground planes, it is necessary to caracterize suc surfaces y performing parametric studies of te unit cell. Te pases of reflected waves can e used to caracterize te performance of HIS structures. e just need to analyze one cell of te HIS reflector to get te reflection pase frequency and of te wole reflector. In tis study, numerical simulation metods are used to analyze te reflection pases of HIS structures. Te Copyrigt to IJAREEIE /ijareeie

2 ISSN (Print) : International Journal of Advanced Researc in Electrical, (An ISO 3297: 27 Certified Organization) Vol. 4, Issue 1, January 215 simulations were carried out using CST microwave studio wit te imposition of a periodic oundary condition (PBC) [9]. Te simulation setup is te same as used in [1]. A. Te first HIS cell cell g (a) Sustrate Patc () Ground Fig.1 Te geometry of te first dual-and HIS cell. (a) top view, () side view. As sown in fig. 1, te first dual-and HIS cell design consists of a concentric square patc wit square ring slot. In [11-12], tis cell as een designed for ifi standards 2.4 GHz and 5.5 GHz. In tis study, te dimensions of te HIS were optimized to acieve te pase around GHz and GHz. Te studied HIS cell is printed on one layer of Roger sustrate wit tickness of 6 mm, relative permittivity of 1.96 and loss tangent of.19. is te cell widt, is te widt of te inner patc, is te widt of te outer patc and g is te gap widt. cell Rflection Pase (degree) =48 (mm) =46(mm) =44(mm) =42(mm) Fig. 2 Te reflection pase curves for different values of Te results of te reflection pase for different values of wen decreasing te widt of te outer patc are presented in fig. 2. From tese results we can see tat from 48 mm to 42 mm, te frequency in wic te reflection pase is Copyrigt to IJAREEIE /ijareeie

3 ISSN (Print) : International Journal of Advanced Researc in Electrical, (An ISO 3297: 27 Certified Organization) Vol. 4, Issue 1, January 215 (resonant frequency) at te ig frequency and is increasing, from 1.63 GHz at 48 mm to 1.9 GHz at 42 mm. ile it increases sligtly in te low frequency and. Fig. 3 sows te reflection pase for different widt of te inner patc. As can e seen from te figure, wen cange from 5 mm to 56 mm, te resonant frequency (wen te reflection pase is ) decreases in te low and from GHz to 1.8 GHz. ile te resonant frequency in te ig and decreases from 1.68 GHz wen is 5 mm to 1.62 GHz wen is 56 mm. Reflection Pase (degree) =5(mm) =52(mm) =54(mm) =56(mm) B. Te second HIS cell Fig. 3 Te reflection pase curves for different values of cell (a) Bottom patc Top patc () Fig. 4 Te geometry of te second dual-and HIS cell. (a) top view, () side view. Te geometry of te second cell is sown in fig. 4. Tis cell consists of two stacked square patces; te smallest is on top of te larger. Te studied cell is printed on two layers of Roger sustrate wit tickness of 3 mm eac one, relative permittivity of 1.96 and loss tangent of.19. Te following are te dimensions of te HIS cell: is te cell widt, is te large patc widt and is te widt of te small patc in top. cell Copyrigt to IJAREEIE /ijareeie

4 ISSN (Print) : International Journal of Advanced Researc in Electrical, (An ISO 3297: 27 Certified Organization) Vol. 4, Issue 1, January 215 Reflection Pase (degree) =64(mm) =67(mm) =7(mm) =73(mm) Fig. 5 Te reflection pase curves for different values of As sown in fig. 5, te reflection pase curves decreases, significantly, in te low frequency and wen te values of te widt of te large patc increase from 64 mm to 73 mm. In te ig frequency and te reflection pase remains te same wit a sligt cange. Reflection Pase (degree) =52(mm) =56(mm) =6(mm) =68(mm) By oserving te reflection pase for different values of Fig. 6 Te reflection pase curves for different values of wic are sown in fig. 6, it can e concluded tat te values of affect te ig frequency and. Te resonant frequency decreases from 1.83 GHz to 1.49 GHz wen increases from 52 mm to 68 mm. Copyrigt to IJAREEIE /ijareeie

5 ISSN (Print) : International Journal of Advanced Researc in Electrical, (An ISO 3297: 27 Certified Organization) Vol. 4, Issue 1, January 215 III. COMPARATIVE ANAYSIS TAB.1 Design specifications of te two HIS cells First cell Second cell Parameters (mm) cell g.7 6 cell Ta. 1 igligts te design specifications of te structures. It is noticeale tat te first dual-and HIS wit one layer is te smallest wit cell size of 58 mm wile te two-layer cell size is 69 mm. Reflection Pase (degree) Cell 1 (one layer) Cell 2 (two layers) Fig. 7 Te reflection pase curves for te two dual-ands HIS cells Fig. 7 sows te reflection pase of te two cells. Te simulation parameters are presented in tale 1. As seen in fig. 7 and tale 3, te first cell wit one layer resonated at two frequencies of 1.22 GHz and 1.68 GHz. Te andwidt etween te +/- 9 degree points in te reflection pase curve of te low resonant frequency is 2% (25 MHz) and at te second resonant frequency is aout 2% (35 MHz). It is ovious tat te andwidt at te low frequency (1.22 GHz) is very narrow. Te reflection pase of te two-layer cell (te second cell),wic is presented in te same figure, is resonated at GHz and 1576 GHz wit a andwidt of 17% and 3.5%,respectively, as presented in tale 2 for low and ig frequencies and. TAB. 2 Resonant frequencies and andwidt of te two cells ow and Hig and Bandwidt (%) Bandwidt (MHz) / f (GHz) Bandwidt (%) Bandwidt (MHz) / f (GHz) First cell 2 25 / / 1.68 Second cell / / Copyrigt to IJAREEIE /ijareeie

6 ISSN (Print) : International Journal of Advanced Researc in Electrical, (An ISO 3297: 27 Certified Organization) Vol. 4, Issue 1, January 215 Based on te results analysis aove, it can e concluded tat te two-layer cell gives te est results. Even tat its andwidt at te ig frequency and is less tan tat given y te first cell. Anoter signification point to notice is tat, te resonant frequency at te ig frequency and for te first cell is not at te desired frequency of GPS standard 2 (1575 MHz). However, for te two-layer cell te low and ig resonant frequencies are at 1 and 2 of GPS standard. IV. CONCUSION In tis work, we ave comparatively investigated te performances of two different dual-and HIS structures. Te geometry of te designed structures was introduced and a parametric study was conducted for eac one. Te reflection pase of te two structures was compared. Te analysis results allow us to see tat te two-layer cell give te est performances. For furter study, it will e necessary to determine te caracteristics (return losses and radiation diagram) of a dual-and antenna wit te presence of eac structure. REFERENCES 1. X.. Bao, G. Ruvio, and M. J. Ammann, "Directional dual-and slot antenna wit dual-andgap ig-impedance-surface reflector," Progress In Electromagnetics Researc C, Vol. 9, pp.1-11, X. Mu,. Jiang, S.-X. Gong, and F.-. ang, "Dual-and low profile directional antenna wit ig impedance surface reflector," Progress In Electromagnetics Researc etters, Vol. 25, pp.67-75, Tior, A. epage, and X. Begaud, "ow profile, directive and ultra wideand antenna on a ig impedance surface," IEEE 3rd European Conference on Antennas and Propagation, D. Sievenpiper,. Zang, R. Broas, N. Alexopolous, and E. Yalonovitc, Hig-impedance electromagnetic surfaces wit a foridden frequency and, IEEE Trans. Microw. Teory Tec., vol. 47, no. 11, pp , Nov H.-J. ee, K.. Ford, and R. J. angley, Independently tunale low-profile dual-and ig-impedance surface antenna system for applications in UHF and, IEEE Transactions on Antennas and Propagation, vol. 6, no. 9, pp , C.H. Huang, C.K. Cen,.H. ee and M.S. in T-slot ig-impedance surface structures for EMC of wireless products 9 t International Conference on Information, Communication and signal Processing (ICICS) T. Yuan, H. Hafdalla-Ouslimani, A. C. Priou, G. acotte, and G. Collignon, "Dual-layer EBG structures for low-profile ``ent'' monopole antennas," Progress In Electromagnetics Researc B, Vol. 47, pp , X. Cen,. i, C.-H. iang, Z.-J. Su, C. Zu, Dual-and ig impedance surface wit musroom-type cells loaded y symmetric meandered slots IEEE transactions on antennas and propagation, VO. 6, NO. 1, OCTOBER N. Capet, C. Martel, J. Sokoloff, and O. Pascal, "Optimum ig impedance surface configuration for mutual coupling reduction in small antenna arrays," Progress In Electromagnetics Researc B, Vol. 32, pp , F. Yang and Y. Ramat-Samii, Reflection pase caracterizations of te EBG ground plane for low profile wire antenna applications, IEEE Transactions on Antennas Propagation, vol. 51, no. 1, pp , Oct S. Zu and R. angley, Dual-and wearale textile antennas over EGB sustrate. IEEE Transactions on Antennas Propagation, Vol 57, pp , M. Mantas, A-C Tarot, S. Collardey, and K. Madjoui, Dual-and CP-fed G-antenna using an EBG structure, Antennas and Propagation Conference (APC '1), ougoroug, UK, pp ,, 21 Copyrigt to IJAREEIE /ijareeie