B.T.P.Madhav et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 5, Issue No. 1, 062 - 066
Log-periodic Toothed Planar Antenna on LCP for Ultra Wide Band Application B.T.P.Madhav, 1VGKM Pisipati, 1K.Sarat Kumar, 1K.V.L.Bhavani, 2VGNS Prasad, 3 K.Praveen Kumar, 4M.Ravi Kumar 1 2
LCRC-R&D, Department of ECE, K L University, Guntur, AP, India
R&D, Department of ECE, Mother Theresa Institute of Science and Technology, Sattupalli 3 4
Associate professor, Department of ECE, Vani School of Engineering, Cheviture
Assistant professor, Department of ECE, Sri Saradhi Institute of Technology, Nuzvid
T
1*
Email:madhav.mtech@gmail.com
frequencies within the operation range limited only by physical size.
ES
Abstract: Ultra wide band technology is a revolutionary wireless technology for transmitting digital data over a wide range of frequency bands with very low power. UWB devices operate by employing very narrow or short duration pulses that result in very wideband transmission bandwidths. In this present paper a novel toothed planar microstrip patch antenna was designed on liquid crystal polymer substrate for UWB applications. Antenna parameters are simulated using commercial Ansoft-HFSS software and presented in this paper.
1.
A
Keywords: LPTPA (Log-periodic toothed planar antenna), liquid crystal polymer substrate, UWB (ultra wide band).
Introduction:
IJ
The toothed antenna comes under the category of log periodic antenna. Toothed antenna follows the angle concept, if one tooth has a width Wo the next smaller one is гWo wide the third is г2Wo and so. Let the width of the widest tooth be W1, which is approximately one quarter wavelength corresponding to lower frequency limit. Then the width of the n th tooth Wn is Wn=W1гn г is a constant representing the ratio of width of (n+1) th tooth to width of nth tooth[1-2]. Taking the logarithm of both sides of above equation yields: logWn = logW1 + nlog г. For a Consequently, the logarithm of Wn increases in equal steps with n. That is, log Wn increases also implied that whatever electrical properties the antenna may have at a frequency f0, will be repeated at all frequencies given by гn fo. Combining the periodicity with the angle concept, the LPTPA has a self complementary configuration. This results in a constant input
ISSN: 2230-7818
In this present work toothed antenna is designed on liquid crystal polymer substrate for the Ultra wideband communication applications. The usage of UWB antennas are increasing due to its extremely fine time and range solution even through lossy, opaque media, large processing gains, immunity from multipaths[3-4]. At higher power levels UWB signals can travel to significantly greater ranges. UWB technology offers major enhancement in three application areas includes communication, Radar and positioning or ranging. The development of UWB technology will help to realize potentials of UWB radars and give advantages to those who will use them widely in various areas. 2.
Antenna specialization:
The proposed log-periodic toothed planar antenna design is shown in figure (1). The operating bandwidth is between 3 to 10 GHZ and substrate dimensions along x-axis and y-axis are 61mm respectively. Thickness of the substrate material is 0.58mm and port gap width is 8.1mm. The tau and sigma are 6.5mm and 8.1mm, the delta and beta angles are 45 degrees and outer radius of toothed arm is 26.9mm. A liquid crystal polymer material is used as substrate in this work and it’s physical, electrical and mechanical properties are characterized, the permittivity of the material is 2.88 and dielectric loss tangent is 0.0004. LCP is gaining its importance in the present day communication due to its flexible design and advantages [5-6].
@ 2011 http://www.ijaest.iserp.org. All rights Reserved.
Page 62
T
B.T.P.Madhav et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 5, Issue No. 1, 062 - 066
Figure (1) log-periodic toothed planar antenna Results and discussion:
dB(St(1,1))
Ansoft NameCorporation X
Return Loss
Y
0.00 m1
3.8485
-24.4567
m2
5.4040
-23.5053
m3
6.5354
-14.7247
m4 -5.00 m5
7.8081
-16.1987
9.0808
-22.7271
LogPeriodicToothed_Antenna_ADKv1
ES
3.
-10.00
Curve Info
dB(St(1,1)) Setup1 : Sw eep1
m3
-15.00
m4
-20.00 Delta(X) 1.5556
-25.00 d( m3,m4 ) 3.00
1.2727
Delta(Y)
Slope(Y)
InvSlope(Y)
0.6116
1.6351
A
Name d( m1,m2)
0.9514m 1
-1.4740 4.00 -1.1581
-0.8635 5.00
m5
m2
6.00
7.00
8.00
9.00
10.00
Freq [GHz]
Figure (2) Frequency Vs Return loss
IJ
A good antenna might have a value of -10dB as 90% of the signal is absorbed and 10% is reflected back. The proposed antenna is giving the excellent return loss curve in the UWB range[7]. The curve has deep and wide dips at frequencies 3.8, 5.4, 6.5, 7.8 and 9.08 GHz. The return loss obtained at these frequencies is -24.45, -23.50, -14.72, -16.19 and 22.72 respectively. Maximum power transfer can be achieved if the impedance of the antenna is matched with the load, which involves complex conjugate of the load impedance. In UWB antennas impedance matching is difficult to achieve. By applying proper mechanism and careful design this problem can be solved [8]. The input impedance smith chart for the proposed UWB antenna is presented in the figure (3). A bandwidth of 78% is achieved from the current design. The rms of 0.3546, gain margin of 6.4832, phase margin of 184.60, phase crossover of 3.57 and gain crossover
ISSN: 2230-7818
of 3.00 is obtained from the input impedance smith chart curve. Input Impedance
Ansoft Corporation
110
100
120 130
LogPeriodicToothed_Antenna_ADKv1
90 80 70 1.00
60
0.50
2.00
50
140
Curve Info
rms
bandw idth(1, 0)
St(1,1)) Setup1 : Sw eep1
0.3546
3.0000
40
150
30
160 0.20
5.00 20
170
10 0.20
180 0.00 -0.00
0.50
1.00
2.00
5.00
0
-170
-10
-160 -0.20
-5.00 -20
-150
-30
-140 -130
-40 -0.50
-2.00
-120 -110
-100
-1.00 -90
-50
-60 -80
-70
Figure (3) input impedance smith chart Impedance mismatch between the transmission line and its load can be measured using VSWR curve. If the VSWR is high then the mismatch will be greater, the minimum VSWR corresponds to a perfect impedance match is unity. Figure (4) shows the VSWR curve for the UWB antenna.
@ 2011 http://www.ijaest.iserp.org. All rights Reserved.
Page 63
B.T.P.Madhav et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 5, Issue No. 1, 062 - 066
VSWRt(LogPeriodicToothedPlanarAntenna1_T1)
Ansoft NameCorporation X
XY Plot 1
Y
4.50 m1
3.8485
1.1274
m2
5.4040
1.1431
m3 4.00 m4
6.5354
1.4496
7.8081
1.3666
m5
9.0808
1.1576
LogPeriodicToothed_Antenna_ADKv1 Curve Info VSWRt(LogPeriodicToothedPlanarAntenna1_T1) Setup1 : Sw eep1
3.50
3.00
2.50
2.00
1.50
m3
Name
Delta(X)
d( m1,m2)
1.5556
Delta(Y) m1 0.0158
1.00 d( m3,3.00 m4)
1.2727
-0.08304.00
Slope(Y)
InvSlope(Y)
0.0102
98.4756
-0.0652
-15.3257 5.00
m4 m5
m2
6.00
7.00
8.00
9.00
10.00
Freq [GHz]
T
Figure (4) Frequency Vs VSWR The VSWR is maintained 2:1 ratio at the desired frequencies. The VSWR of 1.12, 1.14, 1.44, 1.39 and 1.15 is obtained at 3.8, 5.4, 6.5, 7.8 and 9.08GHz respectively. 6.00 m1
180.0000
ff_2D_GainTotal
Y 5.2997
4.00
dB(GainTotal)_1
2.00
0.00
-2.00
-4.00
-6.00 -200.00
-150.00
-100.00
LogPeriodicToothed_Antenna_ADKv1
ES
Ansoft NameCorporation X
-50.00
0.00 Theta [deg]
50.00
100.00
Curve Info m1 dB(GainTotal)_1 Setup1 : LastAdaptive
150.00
200.00
IJ
A
Figure (5) 2D-gain of the UWB antenna
Figure (6) 3D-gain of the UWB antenna
All real antennas will radiate more in some directions than in others, therefore gain is the amount of power that can achieve in one direction at the expense of power lost in the others. Gain is the one of the important parameter with respect to its performance of an antenna. The gain is always related to the main lobe and from figure (5) it is showing 5.29dBi. Figure (6) showing the gain of the LCP substrate log-periodic toothed planar ultra wideband antenna in three dimensional view.
ISSN: 2230-7818
@ 2011 http://www.ijaest.iserp.org. All rights Reserved.
Page 64
B.T.P.Madhav et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 5, Issue No. 1, 062 - 066
LogPeriodicToothed_Antenna_ADKv1 Curve Info
0 -30
dB(GainPhi) Setup1 : LastAdaptive Phi='0deg'
30 -2.00
dB(GainPhi) Setup1 : LastAdaptive Phi='5deg'
-14.00 60
-60 -26.00
dB(GainPhi) Setup1 : LastAdaptive Phi='10deg'
-38.00 -90
dB(GainPhi) Setup1 : LastAdaptive Phi='15deg'
90
dB(GainPhi) Setup1 : LastAdaptive Phi='20deg'
-120
dB(GainPhi) Setup1 : LastAdaptive
120
-150
150 -180
Figure (7) gain-phi In the far field the power radiated in a particular direction is important. In most applications the power radiated from an antenna is measured from the far field region. The figure (7) and (8) shows the radiation pattern of antenna at phi and theta. Radiation Pattern 5
Ansoft Corporation
LogPeriodicToothed_Antenna_ADKv1
dB(GainTheta) Setup1 : LastAdaptive Phi='0deg'
30 0.00
dB(GainTheta) Setup1 : LastAdaptive Phi='5deg'
-10.00 -60
60 -20.00
dB(GainTheta) Setup1 : LastAdaptive Phi='10deg'
-30.00 -90
dB(GainTheta) Setup1 : LastAdaptive Phi='15deg'
90
dB(GainTheta) Setup1 : LastAdaptive Phi='20deg' dB(GainTheta) Setup1 : LastAdaptive
120
150 -180
Figure (8) gain-theta
Peak gain of 3.59 and peak directivity of 3.52 is obtained for the current model. From the table it is clear that the incident and radiated power is very less values of 0.00379 and 0.00185 respectively. 4.
Conclusion:
In this paper the Ultra Wideband log-periodic toothed planar antenna was designed by using Liquid crystal polymer substrate. From the simulation results, we can see that this antenna is well matched and VSWR is less than 2:1on frequency ranges from 3.1 to 10.6 GHz. The radiated field at the front end of the antenna is vertically polarized. Gain of 5.29dB and directivity of 3.56dB is obtained from the current design. This work giving confidence for the applicability of LCP materials in the future UWB technology.
A
5.
Figure (9) Current distribution
IJ
Figure (9) shows the mesh pattern of the toothed antenna. The triangular Jones indicating the current distribution and it is observed that the current distribution is closer at toothed patch. The current distribution indicates the radiation of the antenna around the patch. The antenna parameters and maximum field data tables for the proposed antenna is given below. Antenna Parameters Value/units Quantity 0.00052031 w/sr Max U 3.52 Peak directivity 3.59 Peak gain 1.72 Peak realized gain 0.00185 w Radiated power 0.00181 w Accepted power 0.00379 w Incident power 1.021 Radiation efficiency 1.020 Front to back ratio Table (1) Antenna Parameters
ISSN: 2230-7818
rE Value At Phi At Theta field (v) (degrees) (degrees) Total 0.62635 45 -166 X 0.61194 50 -166 Y 0.20871 0 -92 Z 0.25623 160 42 Phi 0.60639 80 -178 Theta 0.60638 170 180 LHCP 0.48303 70 -150 RHCP 0.47921 70 -30 Table (2) Maximum field data values
ES
-120
-150
1 2 3 4 5 6 7 8
Curve Info
0 -30
S.NO
T
Radiation Pattern 4
Ansoft Corporation
Acknowledgment:
The authors like to express their thanks to the management and department of ECE, K L University for their support and encouragement during this work. Further, VGKM Pisipati acknowledges the financial support of Department of Science and Technology through the grant No.SR/S2/CMP-0071/2008. References: 1)
W. L. Stutzman and G. A. Thiele, Antenna Theory and Design, 2nd Ed., John Wiley and Sons, New York, 1998.
2)
OSD/DARPA, \Ultra-Wideband Radar Review Panel," Assessment of Ultra-Wideband (UWB) Technology, Arlington, VA.: DARPA, 1990.
3)
E. Guillanton, J.Y. Dauvignac, C. Pichot, and J. Cashman, A new design tapered slot antenna for ultra-wideband applications, Microwave Opt Technol Lett 19 (1998), 286–289.
4)
Kishk, A.A. , K.F.Lee, W.C.Mok, and K.M.Luk, “A wideband small size antenna proximately coupled to a hook shape probe,” IEEE Trans. Antennas Propagat., Vol.52, No.1, 59–65, Jan.2004.
5)
Dane C. Thompson, O. Tantot, H. Jallageas, George E. Ponchak, Manos M. Tentzeris, and J.
@ 2011 http://www.ijaest.iserp.org. All rights Reserved.
Page 65
B.T.P.Madhav et al. / (IJAEST) INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING SCIENCES AND TECHNOLOGIES Vol No. 5, Issue No. 1, 062 - 066
6)
G. Zou, H. Gronqvist, J. P. Starski and J. Liu, “Characterization of Liquid Crystal Polymer for High Frequency System-in-Package Applications”, IEEE Transactions on Advanced Packaging, 2002.
7)
Hosseini, S.A. , Z.A tlasbaf, and K.F orooraghi, “A new compact ultra wide band (UWB) planar antenna using glass as substrate,” Journal of Electromagnetic Waves and Applications, Vol.22, No.1, 47–59, 2008.
8)
Liu, L., J.P .Xiong, Y.Z.Yin, and Y.L.Zhao, “A novel dualf- shaped planar monopole antenna for ultra wideband communications,” Journal of Electromagnetic Waves and Applications, Vol.22, Nos.8/9, 1106–1114, 2008.
ES
Author’s Details:
T
Papapolymerou, “Characterization of Liquid Crystal Polymer (LCP) Material and Transmission lines on LCP Substrates from 10 to 110 GHz”, IEEE Transactions on Microwave Theory and Techniques, vol. 52, no. 4, April 2004.
A
B.T.P.Madhav was born in India, A.P, in 1981. He received the B.Sc, M.Sc, M.Tech, MBA degrees from Nagarjuna University, A.P, India in 2001, 2003, 2007, 2009 respectively. From 2003-2007 he worked as lecturer and from 2007 to till date he is working as Asst.professor in Electronics Engineering. He has published more than 25 papers in International and National journals. His research interests include antennas, liquid crystals applications and wireless communications.
IJ
Prof. VGKM Pisipati was born in India, A.P, in 1944. He received his B.Sc, M.Sc and PhD degrees from Andhra University. Since 1975 he has been with physics department at Acharya Nagarjuna University as Professor, Head, R&D Director. He guided 22 PhDs and more than 20 M.Phils. His area of research includes liquid crystals, nanotechnology and liquid crystals applications. He visited so many countries and he is having more than 260 International research publications. He served different positions as academician and successfully completed different projects sponsored by different government and non-government bodies. He is having 5 patents to his credit.
ISSN: 2230-7818
@ 2011 http://www.ijaest.iserp.org. All rights Reserved.
Page 66