International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 –
6464(Print), ISSN 09...
International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 –
6464(Print), ISSN 09...
International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976
6464(Print), ISSN 0976...
International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 –
6464(Print), ISSN 09...
International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 –
6464(Print), ISSN 09...
International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 –
6464(Print), ISSN 09...
International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 –
6464(Print), ISSN 09...
International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 –
6464(Print), ISSN 09...
International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 –
6464(Print), ISSN 09...
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40120140505004

  1. 1. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online), Volume 5, Issue 5, May (2014), pp. 27-35 © IAEME 27 MULTI-SEGMENT CYLINDRICAL DIELECTRIC RESONATOR ANTENNA Ranjana Singh1 , Amit Kumar2 1 (Communication Department, Galgotias University, India) 2 (School of Electrical, Electronics & Communication, Galgotias University, India) ABSTRACT A novel and simple design of a wideband multi-segment cylindrical DRA which is fed by a micro-strip line for broadband operation is proposed in this paper. The proposed structure has a bandwidth of 2GHz from 6.5 to 8.5 GHz which is 50% of the frequency range ranging from 6 to 10 GHz having resonant frequency at 7.408GHz. Reflection coefficient(S11) at resonant frequency is - 66.01dB. Overall Gain is 5.44dB and radiation efficiency is -0.2825dB that is antenna is 93.70% efficient. Total height of proposed structure is 10mm. This low profile antenna is suitable for wireless systems like WLAN, WiMAX, C-Band applications. Simulation is done using CST MICROWAVE STUDIO-10. Details of the proposed antenna and simulated results are presented and discussed. Keywords: Dielectric Resonator Antenna (DRA), Impedance Bandwidth (IBW), Perfect Conductor (PEC), Radiation Efficiency, Reflection coefficient (S11), Resonant Frequency. I. INTRODUCTION DRAs offer primary features like compact size, light weight, and low cost. They have been demonstrated to be practical elements for antenna applications and posses several merits including high radiation efficiency, flexible feeding technique, simple geometry and easy coupling [1-2]. The DRA is fabricated from low-loss dielectric materials. Its resonant frequencies are predominantly a function of DR configuration and dielectric constant. From last few decades there is a deep interest in antenna systems which operate at the higher frequencies [3]. Conventional metallic antennas suffer problems like conductor losses, radiated power capabilities and major problem of fabrication difficulties when their size is reduced to operate in a particular higher frequency band. These short- comings can be over-come if a simply shaped DRA with few conducting surfaces is designed [4-5]. DRAs have attracted the antenna designers in microwave and millimeter wave band due to attractive features which are mentioned above including zero conductor losses. DRAs of low dielectric material, having dielectric constant as (4 <ߝ௥ < 100) are ideally suitable for antenna applications, so INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATION ENGINEERING & TECHNOLOGY (IJECET) ISSN 0976 – 6464(Print) ISSN 0976 – 6472(Online) Volume 5, Issue 5, May (2014), pp. 27-35 © IAEME: www.iaeme.com/ijecet.asp Journal Impact Factor (2014): 7.2836 (Calculated by GISI) www.jifactor.com IJECET © I A E M E
  2. 2. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online), Volume 5, Issue 5, May (2014), pp. 27-35 © IAEME 28 that there can be compromise between size and bandwidth since dielectric constant also affects the bandwidth, as dielectric constant decreases bandwidth increases [5-9]. DRAs are commonly available in rectangular, cylindrical, conical and spherical geometries. The experimental investigation of the cylindrical DRA is done by Long et al. which demonstrated that cylindrical DRAs are capable of providing efficient radiation [10]. The radiation Q-factor of a DR antenna depends on two factors excitation modes as well as the dielectric constant of the ceramic material. As Q-factor increases the bandwidth decreases with increasing dielectric constant [11-12]. For this reason, DRAs of relatively low dielectric constant are almost always used in antenna applications [13].From few decades a substantial amount of research has been done to study about DRAs. It has been demonstrated that rectangular, hemispherical, half-split cylindrical and equilateral triangular shapes can be designed to radiate efficiently through proper choices of feeding technique and position [13-14]. Different types of feeding techniques such as coaxial probe, micro-strip line [15], slotted waveguide [16], dielectric image line [17] and coplanar waveguide (CPW) [18] have been developed till now. In this paper, multi-segment cylindrical DRAs with micro- strip fed is proposed. The proposed structure has matching bandwidth of 50%. II. THEORY To design DRA resonant frequency is one of the important parameter. The approximate calculation of resonant frequency for the TM01δ mode and HE11δ mode for conventional cylindrical DRA can be done by following expressions (1) and (2). ݂௥ ൌ ௖ ଶగ௔ඥఌೝାଶ ට3.83ଶ ൅ గ௔ ଶ௛ …. (1) ݂௥ ൌ ଺.ଷଶସ ඥఌೝାଶೌ ൜0.27 ൅ 0.36 ௔ ଶ௛ ൅ 0.02 ቀ ௔ ଶ௛ ቁ ଶ ൠ …. (2) Where a is radius and h is height of antenna. The resonant frequency of the TM01δ modes of conventional cylindrical DRA can be estimated using the transcendental equations derived from a waveguide model [19]. The first subscript 0 in the notation TM01δ states the order of the Bessel functions of the first and second kind which must be used to calculate the resonant frequency of that mode, the second subscript 1 in the designation of the mode denotes the order of magnitude of the root which is used to calculate the resonant frequency, the third subscript ߜ is merely a coefficient in the argument of a trigonometric function which enters into the expressions for the electric and magnetic fields inside the cavity [19]. The resonant frequency is estimated using a simple waveguide mode of a magnetic wall. Wave numbers are calculated using equations (3), (4) and (5) [20]: ݇௫ ൌ ௠గ ௔ …. (3) ݇௬ ൌ ௡గ ௕ …. (4) ݇௭ tan ቀ ௛௞೥ ଶ ቁ ൌ ඥሺߝ௥ െ 1ሻሺ݇௢ ଶ െ ݇௭ ଶ ) …. (5) Where݇௫, ݇௬ and ݇௭ are wave-numbers in x, y and z directions respectively and ݇௢ denote wave- number in free space, defined as: ݇௢ = (2πfo)/c …. (6)
  3. 3. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 6464(Print), ISSN 0976 – 6472(Online), Volume 5, Issue 5, May (2014), pp. The cylindrical DRA is characterized by their height, radius and dielectric constant, one degree of freedom (aspect ratio radius/height), which determines dielectric constant [19]. Impedance bandwidth is calculated using equation: fh-fl IBW = fc Where fh, fl, fc are higher, lower and cutoff frequency respectively. Voltage standing wave ratio (VSWR) is a measure of how much power is reflected back to the input port or how perfectly antenna is matched to transmission reflection coefficient or return loss [18 III. ANTENNA CONFIGURATION Proposed structure is a multi materials GALLIUM ARSENIDE, ROGERS RT5880 and ROGERS RO3010. Individual segment has radius of 5mm. DR is placed over a substrate made up of material ESL 41110 Antenna is excited using micro-strip calculator. This whole structure is mounted over a ground plane thickness l=2mm. Substrate is nothing but proposed structure is shown in Fig. 1. Figure 1: Final design of proposed m International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 6472(Online), Volume 5, Issue 5, May (2014), pp. 27-35 © IAEME 29 The cylindrical DRA is characterized by their height, radius and dielectric constant, (aspect ratio radius/height), which determines k0 and Q-factor for Impedance bandwidth is calculated using equation: …. (7) are higher, lower and cutoff frequency respectively. Voltage standing wave ratio (VSWR) is a measure of how much power is reflected back to the input port or how perfectly antenna is matched to transmission line. VSWR is defined as VSWR= (1+Γ) / (1 18-20]. ANTENNA CONFIGURATION AND DESIGN Proposed structure is a multi-layered structure designed using three cylindrical segments of materials GALLIUM ARSENIDE, ROGERS RT5880 and ROGERS RO3010. Individual has radius of 5mm. DR is placed over a substrate made up of material ESL 41110 strip fed whose dimensions are calculated using CST line calculator. This whole structure is mounted over a ground plane which is made up of PEC . Substrate is nothing but insulation between micro-strip and ground. Final structure is shown in Fig. 1. (a) (b) proposed multi-stack cylindrical DRA (a) 3D view (b) side view International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – © IAEME The cylindrical DRA is characterized by their height, radius and dielectric constant, offering factor for a given are higher, lower and cutoff frequency respectively. Voltage standing wave ratio (VSWR) is a measure of how much power is reflected back to the input port or how perfectly ) / (1-Γ), where Γ is designed using three cylindrical segments of materials GALLIUM ARSENIDE, ROGERS RT5880 and ROGERS RO3010. Individual cylindrical has radius of 5mm. DR is placed over a substrate made up of material ESL 41110-7C. CST line impedance which is made up of PEC having strip and ground. Final (a) 3D view (b) side view
  4. 4. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online), Volume 5, Issue 5, May (2014), pp. 27-35 © IAEME 30 Thickness of micro-strip line (h) is 1.28mm and width of 2mm. Substrate is of thickness (t) 2mm and have same length & width of 20mm. Properties of materials used for cylinders and substrate are: • Cylinder 1- Have thickness (t1) 3mm made of Rogers RO3010 is a loss-free, normal type material having dielectric constant of 10.2. Permeability µ= 1 and thermal conductivity of 0.66 W/K/m. • Cylinder 2- Have thickness (t2) 2mm, made of Rogers RT5880 is a loss-free, normal type material having dielectric constant of 2.2. Permeability µ = 1 and thermal conductivity of 0.2 W/K/m. • Cylinder 3- Have thickness (t3) 5mm, made of material Gallium Arsenide, it is also a loss-free normal type material having dielectric constant of 12.94, Permeability µ = 1 and thermal conductivity of 54 W/K/m. It has Young’s modulus of 85 kN/mm2 , Poisson’s Ratio of .31 and thermal expansion of 5.8 1e- 6K. • Substrate- ESL 41110-7C is also a loss-free, normal type material having dielectric constant of 4.5. Permeability µ = 1 and thermal conductivity of 3 W/K/m. IV. SIMULATED RESULTS AND PARAMETRIC DISCUSSION A. SIMULATED RESULTS The structure has been simulated and S-Parameter is shown in Fig. 2, we have a resonant frequency at f=7.408GHz with a bandwidth of 2 GHz ranging from 6.5 to 8.5 GHz (where S11<-10 dB). The maximum return loss is up to-66.01dB at the resonant frequency. The return loss, S11 (in dB) is shown in Fig. 2 where we can clearly see the maximum dip is at 7.408GHz. Figure 2: Representation of S11-Parameter. The Far-field radiation pattern at resonant frequency 7.408GHz is shown in Fig. 3 which shows that maximum gain of antenna is 5.44 dB.
  5. 5. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online), Volume 5, Issue 5, May (2014), pp. 27-35 © IAEME 31 Figure 3: 3D view of Simulated far field radiation pattern Fig. 4 and Fig. 5 are representing the simulated 3D Electric field radiation pattern and Magnetic field radiation pattern respectively at resonant frequency 7.408 GHz. Figure 4: E-Field distributions at resonant frequency 7.408GHz Figure 5: H-Field distributions at resonant frequency 7.408GHz Polar plot of Far-field radiation is shown in Fig. 6(a), (b) respectively to show the variation with change in Theta and Phi. Fig. 6(a) is representing Electric monopole structure created as it is centrally excited and its main lobe direction is 27 degree and its magnitude is 5.4 dB. Fig. 6(b) is representing Horizontal Magnetic Dipole whose main lobe direction is 0.0 deg. and its magnitude is - 101.7 dB.
  6. 6. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online), Volume 5, Issue 5, May (2014), pp. 27-35 © IAEME 32 (a) (b) Figure 6: (a) E-Plane (Electric Monopole), (b) H-Plane (Horizontal Magnetic Dipole) Figure 7: VSWR for proposed DRA. The simulated VSWR of proposed multi-layered DRA is shown in Fig. 7. The matching frequency range is from 6.5 to 8.5 GHz where the VSWR < 2 and return loss (S11) < -10 dB.
  7. 7. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online), Volume 5, Issue 5, May (2014), pp. 27-35 © IAEME 33 B. PARAMETRIC DISCUSSION To verify that the proposed structure has best results at optimum parameters, some of the parameters are varied (keeping others constant), results are simulated and compared and are presented in tabular form. Fig. 8 and Table I show that maximum bandwidth is 2GHz when radius of antenna is 5mm keeping other parameters constant. Fig. 9 and Table II represent that maximum IBW and bandwidth is when dielectric constant is 12.94. Figure 8: Variation of S-Parameter with variation in radius(r in mm) of DR TABLE I: S11-parameter and Impedance bandwidth at different Radius of DR Radius(of all three cylinders) in mm Reflection coefficient (dB) Bandwidth ( GHz) Resonant frequency (GHz) IBW (%) 3 - - - - 4 -50 1.6 8.75 18.2 5 -66.01 2 7.408 27 6 - - - 7 -25 - 8.46 - Figure 9: Variation of S-Parameter with variation in (epsilon) Dielectric constant
  8. 8. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online), Volume 5, Issue 5, May (2014), pp. 27-35 © IAEME 34 TABLE II: S11-parameter and Impedance bandwidth at different Dielectric Constants Epsilon Reflection coefficient (dB) Bandwidth ( GHz) Resonant frequency (GHz) IBW (%) 8.94 -18 2 8.75 22 10.94 -25 2 7.75 25 12.94 -66.01 2 7.4 27 14.94 -29 1.75 7.1 24 16.94 -23 1.65 6.8 24 IV.CONCLUSION The multi-segment cylindrical DRA, which provides wide bandwidth in WiMAX and WLAN has been proposed in this paper. The radiation characteristics and reflection coefficient of the proposed antenna are evaluated through simulation studies using CST Microwave Studio 10. By investigation and analysis it is inferred that the bandwidth of the proposed antenna is found to be 50% which covers 7.4 GHz WiMAX band. Advantage of proposed antenna is that it is a low profile antenna with simple design steps. Overall gain of antenna is 5.44 dB and total efficiency of -0.2825 dB at resonant frequency 7.408GHz. REFERENCES [1] R.K. Mongia and P. Bhartia, “DRA- A review and general design relation for resonant frequency and bandwidth,” International Journal of Microwave and Millimeter wave computer aided engineering, vol.4, No.3, pp 230-247, 1994. [2] O. M. H. Ahmed and A. R. Sebak’ “Size reduction and bandwidth enhancement of a UWB hybrid dielectric resonator antenna for short range wireless communications,” Progress In Electromagnetics Research Letters, vol. 19, pp 19–30, 2010. [3] Aldo Petosa, Neil Simons, RiazSiushansian, ApisakIttipiboon, and Michel Cuhaci’ “Aldo Petosa, Neil Simons, RiazSiushansian, ApisakIttipiboon, and Michel Cuhaci,” IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, vol. 48, No. 5, MAY 2000. [4] S. M. Shum and K. M. Luk, “Stacked Annular Ring Dielectric Resonator Antenna Excited by Axi-Symmetric Coaxial Probe,” IEEE Transactions on Antennas and Propagation, vol. 43, pp. 889-892, August 1995. [5] P.Rezaei, M.Hakkak and K. Forooaghi, “Design of wideband dielectric resonator antenna with a two segment structure,” Progress in Electromagnetics Research, PIER 66, pp. 111–124, 2006. [6] James K. Plourde and Chung-L1 Ren, “Application of Dielectric Resonators in Microwave Components”, IEEE Transactions on Microwave Theory and Techniques, vol. 8, pp. 754-770, August 1981. [7] M. Saed and R. Yadla, “Microstrip-fed low profile and compact dielectric resonator antennas,” Progress In Electromagnetics Research, pier 56, pp.151–162, 2006. [8] Michal Okoniewski, Maria A. Stuchly, “A study of the handset antenna and human body interaction,” IEEE Trans. on Microwave Theory and Techniques, vol. 44, no. 10, pp.1855-1864, 1996. [9] Ittipiboon and R. K. Mongia, “Theoretical and experimental investigations on rectangular dielectric resonator antennas,” IEEE Transactions on Antennas and Propagation, vol. 45, No. 9, pp. 1348– 1356, Sept. 1997.
  9. 9. International Journal of Electronics and Communication Engineering & Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online), Volume 5, Issue 5, May (2014), pp. 27-35 © IAEME 35 [10] Stuart A. Long, Mark W. McAllister and Liang C. Shen, “The resonant cylindrical dielectric cavity antenna”, IEEE Transactions on Antenna and Propagation, Vol.31, pp. 406-412, May 1983. [11] R. C. Gupta and S. P. Singh, “Mutual Coupling Between Box-Horn Elements of a Phased Array Terminated in Three-layered Bio-Media,” IEEE Trans. on Antennas and Propagation, Vol. 55, No. 8, pp. 2219– 2227, August 2007. [12] Darko Kajfez and A. A. Kishk, “Dielectric Resonator Antenna- Possible Candidate for Adaptive Antenna Arrays,” Proceedings VITEL 2002, International Symposium on Telecommunications, Next Generation Networks, May 2002. [13] A.A.Kishk, B. Ahn, and D. Kajfez, “Broadband stacked dielectric resonator antennas,” IET, Electron Letters, vol. 25, pp 1232–1233, August 1989. [14] Christopher S. De Young, Stuart A. Long, “Wideband Cylindrical and Rectangular Dielectric Resonator Antennas,” IEEE Antennas and Wireless Propagation Letters, Vol. 5, 2006. [15] Petosa, A., A. Ittipiboon, M. Cuhaci, and R. Larose, “Bandwidth improvement for a microstrip-fed series array of dielectric resonator antennas,” Electron. Letter, Vol. 32, No. 7, 608–609, Mar. 1996. [16] Eshrah, I. A., A. A. Kishk, A. B. Yakovlev, and A. W. Glisson, “Theory and implementation of dielectric resonator antenna excited by a waveguide slot,” IEEE Trans. Antennas Propagation, Vol. 44, No. 53, 483–494, Jan. 2005. [17] Al-Zoubi, A. S., A. A. Kishk, and A. W. Glisson, “Analysis and design of a rectangular dielectric resonator antenna FED by dielectric image line through narrow slots,” Progress In Electromagnetics Research, Vol. 77, 379–390, 2007. [18] Lee, R. Q. and R. N. Simons, “Bandwidth enhancement of dielectric resonator antennas,” IEEE Antennas and Propagation Soc. Int. Symp. Dig., Vol. 3, 1500–1503, Jul. 1999. [19] Raghvendra Kumar Chaudhary, Kumar Vaibhav Srivastava and Animesh Biswas, “An Investigation on Three Element Multilayer Cylindrical Dielectric Resonator Antenna Excited by a Coaxial Probe for Wideband Applications,” IEEE Asia-Pacific Conference on Applied Electromagnetics, 2010. [20] Mohsen Khalily, Md. Kamal A. Rahim, Ahmed A. Kishik, ShadiDanesh, “Wideband P-Shaped Dielectric Resonator Antenna” Radio-Engineering, Vol 22, No. 1, April 2013. [21] B.Ramarao, M.Aswini, D.Yugandhar and Dr.P.V.Sridevi, “Dominant Mode Resonant Frequency of Circular Microstrip Antennas with and without Air Gap”, International Journal of Electronics and Communication Engineering & Technology (IJECET), Volume 3, Issue 1, 2012, pp. 111 - 122, ISSN Print: 0976- 6464, ISSN Online: 0976 –6472. [22] Rajni and Anupma Marwaha, “Role of Geometry of Split Ring Resonators in Magnetic Resonance of Metamaterials”, International Journal of Electronics and Communication Engineering & Technology (IJECET), Volume 4, Issue 7, 2013, pp. 279 - 285, ISSN Print: 0976- 6464, ISSN Online: 0976 –6472. [23] Jitendra Kumar and Navneet Gupta, “Design of Omnidirectional Linearly Polarized Hemispherical DRA for Wideband Applications”, International Journal of Electronics and Communication Engineering & Technology (IJECET), Volume 4, Issue 7, 2013, pp. 261 - 268, ISSN Print: 0976- 6464, ISSN Online: 0976 –6472. [24] Varun Shukla, Arti Saxena and Swati Jain, “A New Rectangular Dielectric Resonator Antenna Compatible for Mobile Communication or Broadband Applications”, International Journal of Electronics and Communication Engineering & Technology (IJECET), Volume 3, Issue 2, 2012, pp. 360 - 368, ISSN Print: 0976- 6464, ISSN Online: 0976 –6472.

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