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					                                                             International Journal of Advances in Science and Technology,
                                                                                                        Vol. 2, No.6, 2011


        Gain Enhanced E- Shape Microstrip Patch
           Antenna at 2 GHZ on Air Substrate
       *1
            K.V.L.Bhavani, 1B.T.P.Madhav, 1P.Poorna priya, 2Prof. Habibulla Khan, 3G.Manoj Kumar,
                                                      3
                                                          N.Durga Indira
                        1
                         Assistant professor, Department of ECE, K.L.University, Guntur, A.P., India
                                2
                                 Head, Department of ECE, K L University, Guntur DT, AP, India
                            3
                             M.Tech project Students, Department of ECE, K L University, AP, India

                                    Email: kbhavani29@gmail.com, madhav.mtech@gmail.com




                                                            Abstract
This paper presents E - shape microstrip patch antenna operates exactly at 2GHz. The proposed antenna will be
very compact, flexible and gives high gain at the operating frequency when evaluated with other designs.E-shape
patch is etched on 150 X 150 mm2 air substrate material with dielectric constant of 1.0 and height of
14.3mm.Wire edge feed is used to make the design so simple and the feed position is (0,-22.5).The antenna is
designed and simulated using CONCERTO software and simulated results are presented. Return loss 2D,3D
gain,E and H Field distributions, pointing vector, polar plots,FD probe results, Electric and magnetic energy
distribution, and quality factor are simulated for the proposed antenna and presented.

Keywords: E-shape microstrip patch antenna, air substrate, gain enhancement.

1. INTRODUCTION
Microstrip patch antenna in its simplest form consists of a radiating patch on one side of a dielectric substrate and a
ground plane on the other side [1]. The proposed antenna design operates at 2GHz finds applications in Mobile
Satellite Service (MSS) Networks in connection with Ancillary Terrestrial Components (ATC) which operates in the
S-Band more specifically between 2.0 GHz to 2.2 GHz [2].

E-shape rectangular microstrip patch is designed with air as a substrate material. Air is an excellent dielectric with
low dielectric constant of 1.0 and dielectric strength Es (KV/mm) of 3 and it can withstand electrostatic fields much
better than high dielectric constant substrates like aluminum oxide [3-4]. Conventional Microstrip patch antenna
designs with thick substrate layer causes major problem associated with impedance matching. E- shape patch is
designed very high above the ground plane with air as a substrate can yields to broadband operation with good
impedance matching compared to other designs with high gain at its operating frequency[5-6]. It is formed by
inserting a pair of wide slits at the boundary of microstrip patch.

The proposed antenna is designed using Concerto software. It is a state of the art system for high frequency field
simulation. The main components are modeller, quickwave simulator, quickwave2D, CLASP, SOPRANO/EV and
post processor. This provides a complete tool chain for RF and microwave electromagnetic design for use on 32 or
64 bit windows platform.Modeller is used to generate data and models for electromagnetic simulation.




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                                                       International Journal of Advances in Science and Technology,
                                                                                                  Vol. 2, No.6, 2011

2. MATHEMATICAL ANALYSIS
The following are the design equations of the single patch design [7].

                                            
The actual length of the patch is L                              --------------------------------------Eq(1)
                                           2 r

Effective relative dielectric permittivity

                                       1
        1 r 1        h 2
reff  r        1  12 w                                      ---------------------------------------Eq(2)
          2   2            

The effective length of the patch is

               c
L eff                                                            ----------------------------------------Eq(3)
          2f 0 reff

The extension length due to fringing field,

                                 W
                  (reff 0.3)(     0.264)
L  0.412h                      h                                ----------------------------------------Eq(4)
                                   W
                  (reff   0.258)(  0.8)
                                   h

3. ANTENNA DESIGN SPECIFICATIONS
The geometrical configuration of the proposed E shape rectangular microstrip patch antenna is shown in Fig 1.Table
2.1 gives dimensions of the each element used to design the patch.




                                  Fig 1: E shape rectangular microstrip patch

          S.No               Element        Total                      X axis (mm)                Yaxis(mm)
                                            Dimensions (mm)
          1                  patch          L=105,W=65                 -52.5 to 52.5              -32.5 to 32.5
          2                  slot1          l =18,w1=6.3               7.65 to 13.95              -32.5 to 14.5
          3                  slot2          l =18,w1=6.3               -7.65 to -13.95            -32.5 to 14.5
          4                  substrate      L=150,W=150,h=14.3         -75 to 75                  -75 to 75
          5                  ground         L=150,W=150                -75 to 75                  -75 to 75
          6                  Feed (dp)      Length=4,radious=0.6       0                          -22.5
                                 Table 3.1 E shape rectangular MSPA with design values




June Issue                                          Page 52 of 102                                        ISSN 2229 5216
                                                      International Journal of Advances in Science and Technology,
                                                                                                 Vol. 2, No.6, 2011

Fig 1 shows E-shape patch designed on ground plane of size 150X150mm2 with air as a substrate material whose
permittivity value is 1.0 and 14.3mm height[9],[10].

Fig 2 shows the designed patch model in CONCERTO.




                          Fig 2 CONCERTO model for E shape microstrip patch antenna

Wire edge feeding is used for the proposed patch antenna to reduce the complexity [11] and the feed location is
shown in Fig 3.




                                                Fig 3 Feed location

4. EXPERIMENTAL RESULTS AND DISCUSSION

4.1 Return loss vs Frequency:
S11 represents how much power is reflected from the antenna. If S11=0 dB, then all the power is reflected from the
antenna and nothing is radiated. If S11=-10 dB, this implies that if 3 dB of power is delivered to the antenna, -7 dB
is the reflected power. The rest was accepted by the antenna. This accepted power is either radiated or absorbed as




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                                                      International Journal of Advances in Science and Technology,
                                                                                                 Vol. 2, No.6, 2011

losses within an antenna. Since antennas are typically designed to be low loss, the majority of the power delivered to
the antenna is radiated. For the proposed E shape rectangular microstrip patch antenna the return loss is -14.022dB
at center frequency of 2.0 GHz. Return loss versus frequency curve is shown in Fig 4.




                               Fig 4 Return loss Vs frequency: -14.022dB at 2.0 GHz.

4.2 3D radiation pattern:
The 3D radiation pattern gives the far field calculation at the designed frequency. Fig 5 shows 3D radiation pattern
simulated at the center frequency of 2.0 GHz. It shows that the gain value obtained as 9.2647dB at 2.0GHz.




                                    Fig 5 3D radiation pattern: gain is 9.2647dB

4.3 Polar results:
Fig 6a shows the radiation pattern in polar coordinates when θ=900 and θ varies from -900 to 900




June Issue                                         Page 54 of 102                                    ISSN 2229 5216
                                                         International Journal of Advances in Science and Technology,
                                                                                                    Vol. 2, No.6, 2011

Fig 6b shows the radiation pattern in polar coordinates when Ф=00 and θ varies from -900 to 900




        Fig 6a: Polar results when θ=900 and                             Fig 6b: Polar results when phi 00 and
             theta -900 to 900                                                           Theta -900to 900

4.4 Field distributions (v/mm) and pointing vector:
Fig 7a and Fig 7b shows E field and H field distributions respectively. Values are found to be 9.946226e-04 V/mm
and 2.111027e-03V/mm respectively. Fig 7c shows the pointing vector S=E X H.measured value for S is 4.286725e-
06 W/mm2.




             Fig 7a E-field distribution: 9.946226e-04          Fig 7b H-field distribution: 2.111027e-03




June Issue                                         Page 55 of 102                                     ISSN 2229 5216
                                                      International Journal of Advances in Science and Technology,
                                                                                                 Vol. 2, No.6, 2011




                                   Fig 7c Pointing vector: 4.286725e-06 W/mm2

4.5 Energy (Electric and magnetic) and quality factor:
Fig 8 shows energies and quality factor .It is observed that the Electric energy is 4.546091e-005J ,Magnetic energy
is 0.002854227J and total energy is 0.002899688 J and quality factor is found to be 1.234567e-10.




Fig 8 : Energies and quality factor: Electric energy 4.546091e-005J Magnetic energy 0.002854227J and total energy
                                  0.002899688 J and quality factor is 1.234567e-10

4.6 FD probe results:
Fig 9a and Fig 9b shows the FD probe results in line and polar form respectively




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                                                       International Journal of Advances in Science and Technology,
                                                                                                  Vol. 2, No.6, 2011




                Fig 9a: FD probe results lin form             Fig 9b: FD probe results in polar form

5. CONCLUSIONS
A novel low cost, compact, high gain E- shape rectangular microstrip patch antenna with air substrate material has
been proposed and experimentally studied. The proposed antenna gives return loss of -14.022dB at 2.0 GHz with
high gain of 9.2646dB. The proposed model operates at 2 GHz so it is suitable for S band applications. Different
performance evaluation parameters like 3D radiation pattern, 2D polar plots, energies, qualityfactor, field
distributions, pointing vector and FD probe results has been presented. This slot model results giving encouragement
for designing compact antennas with gain enhancement.

ACKNOWLEDGEMENT
The authors gratefully acknowledge the management of KL University and department of Electronics and
communication engineering for their support.

REFERENCES
[1] “Microstrip Antenna Design Handbook”, R. Garg, P. Bhartia, I. J. Bahl, and A. Ittipiboon, Editors, Artech
House, 2001.

[2] “Suspended microstrip patch antenna for wireless applications”, T.Shanmuganantham, Dr.S.Raghavan,
International Journal of Microwave and optical technology, Vol 5 No3May 2010

[3] “Microwave substrates support MIC technology,” M. Olyphant, Jr. and T. E. Nowicki, Microwaves, Part I, vol.
19,no. 12, pp. 74-80, Nov. 1980.

[4]   “performance    evaluation    of    microstrip   square patch    antenna    on    different    substrate
materials”B.T.P.Madhav,D.Rakesh,P.Rakesh kumar, Prof. Habibulla khan , Ch Sri kavya,Journal of theoretical and
Applied Information Technology.30th April 2011.vol.26.No.2.

[5] “Compact and Broad band microstrip patch antennas”, K.L.wong, New York, Ny: Johnwiley and sons Inc 2002

[6] “Slotted rectangular microstrip antenna for bandwidth enhancement”, Sze, J.Y. and K.L., Wong, 2000. IEEE
Transactions on Antennas and Propagation 48, pp. 1149-1152.

[7] “Antenna theory”, Constantine A.Balanis, John wiley & sons Inc.2nd edition.



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                                                      International Journal of Advances in Science and Technology,
                                                                                                 Vol. 2, No.6, 2011


[8] “Microstrip and printed antenna design”, Randy Bancroft, second edition.Scitech Publishing, 2009

[9]“Wide-Band E Shaped Patch Antennas for Wireless Communications,” F. Yang, X. -X. Zhang, X. Ye, and Y.
Rahmat-Samii, IEEE Trans.Antennas Propagation, vol. 49, no. 7, pp. 1094-1100, July. 2001.

[10] “New Multiband E-shape Microstrip patch antenna on RT DUROID 5880 substrate and RO4003 substrate for
pervasive wireless communications “Dr.Anubhutikhare,Rajesh nema,purangour.,International journal of computer
applications(0975-8887)Volume 9-No.8,November2010.

[11] “Study of Micro Strip Feed Line Patch Antenna”, Ahmed H. Reja, Antennas and Propagation International
Symposium, vol. 27, pp. 340-342 December 2008.



Author’s Details:

        B.T.P.Madhav was born in India, A.P, in 1981. He received the B.Sc, M.Sc, MBA, M.Tech degrees from
        Nagarjuna University, A.P, India in 2001, 2003, 2007, and 2009 respectively. From 2003-2007 he worked as
        lecturer and from 2007 to till date he is working as Assistant professor in Electronics Engineering. He has
published more than 45 papers in International and National journals. His research interests include antennas, liquid
crystals applications and wireless communications.



      K.V.L.Bhavani is working as Assistant professor in the E.C.E. Department of KL University. She has
      completed her B.Tech from RVR & JC Engineering College and M.Tech from KL college of Engineering.
      She is pursuing her PhD in Microstrip Dual band Dual Polarized Antennas from K L University. She
published Three International, one national Journal paper and two national conference papers. She has been
Involved in Teaching from last five years to UG and PG Levels. Her research interests include antennas and wireless
communications.



        Prof. Habibulla khan born in India, 1962. He obtained his B.E. from V R Siddhartha Engineering College,
        Vijayawada during 1980-84. M.E from C.I.T, Coimbatore during 1985-87 and PhD from Andhra University
        in the area of antennas in the year 2007.He is having more than 20 years of teaching experience and having
        more than 20 international, national journals/conference papers in his credit.Prof. Habibulla khan presently
        working as Head of the ECE department at K.L.University. He is a fellow of I.E.T.E, Member IE and other
bodies like ISTE. His research interested areas includes Antenna system designing, microwave engineering, Electro
magnetics and RF system designing.



      P.Poorna priya is working as Assistant professor in the ECE Department of KL University. Priya
      completed her M.Sc from Andhra University and M.Tech from KL college of Engineering. She is pursuing
      her PhD in Microstrip Slot Antennas from K L University. She published one International, one national
      Journal paper and two national conference papers She has been Involved in Teaching from last three years to
UG students. Her field of Interest is in Communication systems, antennas and Image Processing.




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