Design CPW-Fed Printed Monopole UWB Antenna for Band Notched Applications

Design CPW-Fed Printed Monopole UWB Antenna for Band Notched Applications

Sandeep S. Nagre1

E&TC Department

Smt. Kashibai Navale College of Engineering Pune, India

A. S. Shirsat2

E&TC Department

Smt. Kashibai Navale college of Engineering Pune, India

AbstractA coplanar waveguide (CPW)-fed printed monopole UWB antenna is proposed. The antenna has dual band notched characteristics for ultra-wideband (UWB) applications. The proposed CPW-fed antenna consist of stepped feed line, stepped ground plane, stepped rectangular patch, U-slot, and C-slot to improve the bandwidth. By removing a C shaped slot and a U shaped slot from stepped patch, the band reject property is obtained at 3.4GHz/4.4GHz. The antenna is designed on the FR4 epoxy substrate with 24 (length) x 24 (width) surface area. A 50 Co-Planar Waveguide (CPW) transmission line is used to feed the printed stepped patch. The design and simulation of the antenna is completed by High Frequency Structure Simulator (HFSS) software. High Frequency Structure Simulator is frequency domain simulation software. Finite Element Method (FEM) method is in HFSS software used for antenna structure optimal design and performance simulation. The simulation result shows that, the compact antenna has good results including consistent radiation patterns, stable gain, with better return loss, broadband impedance matching.

KeywordsCPW-fed, UWB antenna, feed lines, monopole antenna.

1. INTRODUCTION

   An antenna is a specialized transducer that converts radio frequency (RF) field into alternating currents (AC) or vice_ versa. In recent year, Ultra Wide-Band (UWB) antennas plays vital role in wireless communication system after the Federal Communication Commission (FCC) ruling in Feb 2002 for spectrums 3.1 to 10.6 GHz commercial use of the UWB communication system[1]. Ultra Wide-Band (UWB) occupies 500 MHz signal bandwidth. Now a day, the increase growth of ultra wide-band wireless technology has motivated researchers to design a compact size of UWB antenna. This is because UWB antenna has some merits as high speed data rate, simple structure, low cost, and extremely low spectral power. UWB antenna having so many types such as TEM horn, spiral, Vivaldi, bow-tie and dielectric loaded antenna, which covers entire 3.1-10.6 GHz frequency band. UWB also have wide applications in short range and high speed wireless system such as medical imaging, ground penetrating radar, C-band, HIPERLAN, Worldwide Interoperability for Microwave (Wimax), most among them is Wireless Local Area Network (WLAN). WLAN operate with center frequency of 2.4 GHz, 5.2GHz and 5.8 GHz, which create interference with functioning of UWB system. By designed band notched

   characteristics the electromagnetic interference is avoided in UWB system. Band notched characteristics obtained by removing different shaped slots like as U-slot, C-slot, and L- slot etc. from the patch of antenna.

   Design of UWB monopole antennas mainly include two types as printed planar monopole antenna and metal plate antenna. Mostly planar printed monopole antenna used in UWB application as they have the regular shapes such as circular, elliptical, rectangular, square, hexagonal, pentagonal and modified elliptical etc. Printed monopole antenna is compact in structure, good radiation patterns and easy to fabricate. The antenna increases their band width by changing the shape of the ground plane and radiation patch. For example, in [2]-[4], the circular and rectangular monopole antenna were modified and proposed antenna show very large impedance bandwidth. In [5]-[6], impedance bandwidth of the antenna is upgraded by the way of CWP-fed. In [7], band notched characteristics has obtained by removing C-shaped slot in radiator and one rectangular slot in ground plane.

   Finite Element Method (FEM) method is used for antenna structure optimal design and performance simulation. Finite Element Method (FEM) is frequency domain technique based full-wave computational technique. A full-wave computational technique gives a complete solution to Maxwells equations within the computational space for all conductors. This paper proposed a compact and simple CPW fed monopole antenna with band notched characteristic on 3.4GHz and 4.4GHz. The band notch characteristics are achieved by removing U shaped and one C shaped slot from patch and feed by 50 transmission line. The optimization of the design and subsequent simulations are done with HESS software which is based on FEM. The proposed antenna provides a good bandwidth with VSWR<2. Both return loss and gain of the antenna are affected by dielectric constant of substrate. The center frequency of the band notched finely balanced by changing the position and dimension of the slots. Fig.1. show design methodology flow chart for CPW-fed monopole antenna.

2. ANTENN DESGIN

   Figure.2 shows the geometry and configuration of UWB monopole antenna with dual band characteristic Antenna consists of rectangular patch, steeped ground plane feed lines

   to improve the input impedance bandwidth and radiation patterns. Antenna is printed on FR4 epoxy substrate with thickness of 1.5mm and relative permittivity or dielectric constant of 4.4 and tangent loss of 0.002. The printed monopole antenna has compact size 24×24 mm2. As shown in figure an one U shaped and C shaped slot are cut on the stepped patch to achieve band notch characteristics, which is used to avoiding electromagnetic interference. The CPW fed transmission line is designed with 50 characteristic impedance with 3mm feed line width and 2.5mm ground gap. HFSS is frequency domain simulation software based on FEM which gives a better simulation results in terms of radiation pattern and stable gain and consistent input impedance bandwidth. The design parameter are L0=24mm, W0=24mm, H0=10mm, H2=4mm, SW1=20.6mm, Slot1=0.2mm, SW2=8.8mm, SS2=2.4mm, Slot2=0.2mm, GW1=8mm, CW1=3mm, CH1=2mm, CH2=5mm, CH3=8.5mm.

   Literature survey on CPW fed monopole antenna

   Design of CPW-fed monopole

   Theoretical and specification

   Simulation

   Fabrication

   Measurement

   Modify

   Comparison No and result

   Fig.2. Geometry of CPW-Fed Monopole Antenna

3. RESULT AND DISCUSSION

   The CPW-fed printed monopole antenna simulated by HFSS software, which gives a better performance of returns loss, radiation pattern for both E-plane and H-plane, stable gain and VSWR. The frequency domain characteristic of the antenna is obtained by using the Finite Element Method (FEM) of the simulation data. Fig. 3 show simulated results show that the antenna has return loss with -10dB impedance bandwidth covering the frequency range 5-10.6GHz with the modified rectangular in the ground plane and radiation patch, good impedance matching is obtained, and the return loss.

   The simulated VSWR of the dual band notched antenna is shown in figure 4. It is noted from the simulated results that the antenna covers the frequency range 5-10.6GHz and has dual band notched characteristics (VSWR>2) in the 3.4 GHz and 4.4GHz. Center frequency of band notched band is affected by the length and location of C-slot and U-slot.

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   Name X Y m10.00 1.6000 -19.7027

   m2 4.2000 -10.3672

   m3 5.1000 -10.3045

   m4 10.5000 -9.0439

   -5.00

   return loss

   HFSSDesign1 ANSOFT

   Curve Info dB(S(1,1))

   Setup1 : Sweep

   CPW-fed monopole antenna successful

   dB(S(1,1))

   -10.00

   m4

   m2 m3

   Fig.1. Design Methodology Flow Chart

   -15.00

   m1

   -20.00

   -25.00

   1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00

   Freq [GHz]

   Fig.3. Simulated Return Loss of Proposed Antenna

   Y

   X

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   3000

   6.359

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   7.79

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   9

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   VSWR(1)

   7.00

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   6.00

   VSWR(1)

   5.00

   4.00

   3.00

   2.00

   t S p

   1. E-plane

   1.00

   1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00

   Freq [GHz]

   Fig.4. Simulated VSWR of Proposed Antenna

   The far-field radiation characteristics at 1.6, 4.2, 6.4 and

   1. GHz are given in Figs. 5-8, respectively.

      1. E-plane

      2. H-plane

   Fig. 5. Simulated Radiation Patterns at 1.6 GHz.

   b) H-plane

   Fig. 6. Simulated Radiation Patterns at 4.2 GHz.

   b) E-plane

   1. H-plane

      Fig. 7. Simulated Radiation Patterns at 6.4 GHz

      1. E-plane

         is 24×24 mm2. The antenna has simple structure, compact size, easily fabricated on epoxy substrate with low manufacturing cost and good wideband characteristic. Use of the U slot and C slot, the gain performance of antenna is increased over the entire operation bandwidth. Its -10 db band is extended up to 8.5 GHz. Band notched characteristics at 3.1GHz and 5.2 GHz are separately achieved by removing one C-slot and U-slot in the stepped radiation patch. Simulation results show that, the antenna has improved results in terms of returns loss, gain, and radiation patterns.

         ACKNOWLEDGMENT

         It is my pleasure to get this opportunity to thank my beloved and respected Guide Prof. A.S. Shirsat who imparted valuable basic knowledge of Electronics and telecommunications specifically related to Microwave Domain. We are grateful to Elec. & Comm. Smt. Kashibai Navale College of Engineering, Pune for providing us infrastructure facilities and moral support.

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      2. H-plane

   Fig. 8. Simulated Radiation Patterns at 9.8 GHz.

   peak gain

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   REFERENCES

   1. Jingjing Li, Xueguan Liu, Huiping Guo, Ying Wang, Yong Huang, A Compact CPW-Fed UWB Antenna with Dual Band-Notched Applications School of Electronic and Information Engineering, Soochow University, Suzhou Keylab of RF and Microwave Millimeter Wave Technology, 2012, vol.12.

   2. X. X. He and H. W. Deng, Modified ultra wideband circular printed monopole antenna, Trans. Nan. Jing University Aeronaut. Astronaut. vol. 25, no.3,pp. 214-218, sep. 2008.

   3. K. P. Ray, Y. Ranga, and P. Gabhale, Printed square monopole antenna with semicircular base for ultra-wide bandwidth, Electron. Lett, Mar. 2007, vol. 43, no. 5, pp. 1314.

   4. M. John and M. J. Ammann, Optimization of impedance bandwidth for the printed rectangular monopole antenna, Microw. Opt. Technol. Lett.,

      6.00

      4.00

      dB(PeakGain)

      2.00

      0.00

      -2.00

      -4.00

      -6.00

      '

      1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00

      Freq [GHz]

      vol. 47, no. 2, pp. 153154, Aug. 2005

   5. W. Tong and Z. R.Hu, A CPW fed circular monopole antenna for ultra wideband wireless communications, in Proc. IEEE AP-S Int. Symp,2005, vol. 3A, pp. 528531.

   6. Chao Deng, Yong-jun Xie, and Ping Li, CPW-Fed Planar Printed Monopole Antenna with Impedance Bandwidth Enhanced IEEE Antennas and Wireless Propagation Letters, vol. 8, 2009.

   7. L. Luo, Z. Cui, J.-P. Xiong, X.-M.Zhang, and Y.-C. Jiao, "Compact printed ultra-wideband monopole antenna with dual band-notch characteristic," Electron.

   8. F-J. Wang, X -x. Yang, J -So Zhang, G -Po Guo and J -x. Xiao, "A band-notched ring monopole antenna," Microwave Opt. Techno!.Lett, Jul. 2008, vol. 50, no.7, pp.l882-1884.

   9. Junwei Lu, David Ireland and Andrew Lewis, Multi-objective Optimization in High Frequency Electromagnetic an Effective Technique for Smart Mobile Antenna IEEE Transaction On Magnetics, Vol. 45, No. 3, March 2009, pp1072-1075.

   Fig.9. Simulated Peak Gain of Proposed Antenna

   Figure 9 show simulated peak gain of proposed antenna. Figure shows that the gain decreases abruptly at 4.2GHz. Which mean good band-notched characteristic have been obtained and interference can be minimized for UWB antenna.

4. CONCLUSIONS

A compact CPW-Fed printed monopole antenna with band notched characteristic for ultra wideband applications has been implemented in this paper. FEM in the frequency domain technique has been used for simulation, to cover a wide frequency range with time domain code. The total antenna size