Rectangular Patch Array Antenna with Liquid Crystal

Substrate for Ka and Q Band Applications

I.Govardhani1

1.Associate Professor, Department of ECE, K

L University

govardhanee@gmail.com

M.Venkata Narayana2

2.Associate Professor, Department of ECE, K

L University

venqut@gmail.om

Abstract:

This paper mainly deals with the design of

Microstrip rectangular patch array antenna on liquid

crystal substrate at 40GHz. The antenna parameters

are simulated using commercial Ansoft HFSS software

and the detailed explanation of performance

evaluation is presented. A 4x4 rectangular patch array

was designed on liquid crystal substrate material and

their return loss, input impedance, gain and antenna

parameters are studied and presented in this paper.

Keyword: Liquid crystal substrate, phased array

antenna, micro strip

1 Introduction.

Micro strip patch antenna consists of a

radiating patch on one side of a dielectric substrate,

which has a ground plane on the other side. A Micro

strip patch antenna/patch antenna is a narrowband,

wide-beam antenna fabricated by etching the antenna

element pattern in metal trace bonded to an insulating

dielectric substrate with a continuous metal layer

bonded to the opposite side of the substrate which

forms a ground plane.

2 Antenna Model.

Fig:1:antenna model

3 Antenna Design considerations.

A 4X4 rectangular patch array antenna with liquid

crystal substrate has been designed and simulated at

40GHz frequency in this paper. We have taken liquid

crystal dielectric constant (Єr) as 3 and loss tangent (δ)

as 0.003. If „L‟ is the resonant length of patch,

normally width (W) should be larger than L so that

large bandwidth can be obtained. Here we have taken

width (W) as 1.5 times of length (L). Height of the

dielectric substrate should be in between 0.003 λ0 and

0.05λ0. We have taken 0.02 times of λ0. As 50Ω

coaxial cables are used normally, feed point is taken

where 50Ω resistance occurs.

4 Patch Model.

Fig:2:patch model

5 Liquid crystal substrate.

Liquid Crystal Polymer (LCP) is a fairly new

and promising thermoplastic organic material. It can be

used as a low-cost dielectric material for high-volume

large-area processing methods that provide very

reliable high-performance circuits at low cost. It has

impressive electrical characteristics, which is indirectly

related to its low and stable water absorption rate

(<0.04%). It has a nearly constant dielectric constant

Govardhani et al, International Journal of Computer Science & Communication Networks,Vol 2(1), 16-21

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ISSN:2249-5789

of 3 over the entire RF range up to 110 GHz. In

addition, LCP has a very low loss tangent of only

0.002, which increases to only 0.0045 at 110GHz,

thereby making LCP very suitable in designing mm-

wave applications. LCP is flexible, recyclable,

impervious to most chemicals, and it is stable up to its

high melting temperature making LCP an ideal choice

for circuits operating in all kinds of environments.

6 Simulation &Analysis.

The designed antenna is simulated using

HFSS software. The results obtained are mentioned

below.

6.1 Return loss Curve.

Fig:3:return loss

A return loss of -17.76dB is obtained at 52.5GHz

6.2Gain.

The ratio of the intensity, in a given direction, to the

radiation intensity that would be obtained if the power

accepted by the antenna were radiated isotropically.

6.2.1 3-D Gain.

Fig:4:3D gain

6.2.2 2D Gain.

Fig:5:2D gain

For the antenna model a 3D Gain of 8.48dB and a 2D

Gain of 6.28dB is obtained.

6.3 E-field pattern.An electric field can be

visualized by drawing field lines, which indicate both

magnitude and direction of the field. Field lines start

on positive charge and end on negative charge. The

direction of the field line at a point is the direction of

the field at that point. The relative magnitude of the

electric field is proportional to the density of the field

lines.

Fig:6:E-field parren

6.4 H-field Pattern.

In the case of the same linearly polarized antenna, this

is the plane containing the magnetic field vector and

the direction of maximum radiation. The magnetic

field or "H" plane lies at a right angle to the "E" plane.

For a vertically-polarized antenna, the H-plane usually

coincides with the horizontal/azimuth plane. For a

horizontally-polarized antenna, the H-plane usually

coincides with the vertical/elevation plane

20.00 25.00 30.00 35.00 40.00 45.00 50.00 55.00 60.00Freq [GHz]

-18.00

-16.00

-14.00

-12.00

-10.00

-8.00

-6.00

-4.00

-2.00

0.00

dB

(St(

1,1

))

Ansoft Corporation Patch_Antenna_ADKv1Return Loss

m1

m2m3

Curve Info

dB(St(1,1))

Setup1 : Sw eep1

Name X Y

m1 33.8776 -12.7700

m2 52.6531 -17.6775

m3 53.4694 -17.7673

-200.00 -150.00 -100.00 -50.00 0.00 50.00 100.00 150.00 200.00Theta [deg]

-60.00

-50.00

-40.00

-30.00

-20.00

-10.00

0.00

10.00

Y1

Ansoft Corporation Patch_Antenna_ADKv1ff_2D_GainTotal

m1 m2

m3m4

Curve Info

dB(GainTotal)

Setup1 : LastAdaptive

dB(GainTotal)_1

Setup1 : LastAdaptive

Name X Y

m1 -14.0000 5.5710

m2 30.0000 6.2871

m3 14.0000 -5.7168

m4 2.0000 -6.0097

Govardhani et al, International Journal of Computer Science & Communication Networks,Vol 2(1), 16-21

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ISSN:2249-5789

Fig:7:H-field pattern

6.5 Radiation pattern of Gain total.

Fig:8:radiation pattern of gain total

6.6 Radiation pattern of Gain in Theta

direction.

Fig:8:Radiation pattern gain in Theta direction

6.7 Radiation pattern of Gain in Phi direction.

Fig:9:Radiation pattern of gain in Phi direction

6.8 Axial Ratio.

Axial Ratio is the ratio of peak value in the major lobe

direction to peak value in the minor lobe direction.

Fig:10:Axial ratio

Table 1: Antenna parameters obtained

S.No. Quantity For LC

Substrate Є=

3, δ=0.003

1 Rms Value 16.87

2 Phase margin 262.025

3 Gain cross over 20.00

4 Band width 30.61

5 Gain 10.61

6 Phase cross over 34.01

7 Gain margin 13.6

8 Conclusions

The Microstrip patch antenna with liquid

crystal substrate at 40GHz will work properly because

of the high gain. As it is constructed with liquid crystal

substrate, it if very flexible. This antenna can be mould

into any shape and it is stable at high temperatures.

Thus it is most suitable for circuits for operating in all

kinds of environments. This antenna is useful in

millimeter wave communication applications.

9 Acknowledgements

We would like to express our thanks to the

department of ECE and management of KL University

-38.00

-26.00

-14.00

-2.00

90

60

30

0

-30

-60

-90

-120

-150

-180

150

120

Ansoft Corporation Patch_Antenna_ADKv1Radiation Pattern 9

Curve Info

dB(GainTotal)

Setup1 : LastAdaptive

-46.00

-32.00

-18.00

-4.00

90

60

30

0

-30

-60

-90

-120

-150

-180

150

120

Ansoft Corporation Patch_Antenna_ADKv1Radiation Pattern 8

Curve Info

dB(GainTheta)

Setup1 : LastAdaptive

-46.00

-32.00

-18.00

-4.00

90

60

30

0

-30

-60

-90

-120

-150

-180

150

120

Ansoft Corporation Patch_Antenna_ADKv1Radiation Pattern 7

Curve Info

dB(GainPhi)

Setup1 : LastAdaptive

12.00

24.00

36.00

48.00

90

60

30

0

-30

-60

-90

-120

-150

-180

150

120

Ansoft Corporation Patch_Antenna_ADKv1Radiation Pattern 10

Curve Info

dB(AxialRatioValue)

Setup1 : LastAdaptive

Govardhani et al, International Journal of Computer Science & Communication Networks,Vol 2(1), 16-21

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ISSN:2249-5789

for their continuous support and encouragement during

this work.

10 References:

[1] Microstrip Antennas: The Analysis and Design of Microstrip Antennas and Arrays, David M. Pozar and Daniel H. Schaubert, Editors, Wiley/IEEE Press, 1995. [2] Constantine A. Balanis; Antenna Theory, Analysis and Design, John Wiley & Sons Inc. 2ndedition. 1997. [3]Comparative Analysis of Exponentially Shaped Microstrip-Fed Planar Monopole Antenna With and Without Notch M. Venkata Narayana1, I.Govadhani2, K.P.Sai Kumar, K. Pushpa Rupavathi [4] Liquid Crystal Polymer (LCP): The Ultimate Solution for Low Cost RF Flexible Electronics and Antennas, Rushi Vyas, Amin Rida, Swapan Bhattacharya and Manos M. Tentzeris, IEEE 2007. [5]M A Matin, M.P Saha, H. M. Hasan “Design of Broadband Patch Antenna for WiMAX and WLAN” ICMMT 2010 Proceedings, pp. 1-3 [6] F. Yang, X. X. Zhang, X. Ye, and Y. Rahmat-Samii, “Wide-band Eshaped patch antennas for wireless communications,” IEEE Trans. Antennas Propag., vol. 49, no. 7, pp. 1094–1100, Jul. 2001. [7]M. Sanad, “Double C-patch antennas having different aperture shapes,” in Proc. IEEE AP-S Symp., Newport Beach, CA, Jun. 1995, pp. 2116–2119. [8] Shackelford, A.K., Lee, K.F., and Luk, K.M.: „Design of small-size widebandwidth microstrip-patch antennas‟, IEEE Antennas Propag. Mag., 2003, AP-45, (1), pp. 75–83 [9] H. F. AbuTarboush, H. S. Al-Raweshidy, and R. Nilavalan, “Triple band double U-slots patch antenna for WiMAx mobile applications,” in Proc. Of APCC, Tokyo, Feb. 2008, pp. 1-3. [10]Waterhouse, R.B.: „Broadband stacked shorted patch‟, Electron. Lett. 1999, 35, (2), pp. 98–100 [11] Guo, Y.X., Luk, K.M., and Lee, K.F.: „L-probe proximity-fed shortcircuited patch antennas‟, Electron. Lett., 1999, 35, (24), pp. 2069–2070 [12]K.L. Lau and K.M. Luk ” Wideband folded L-slot shorted-patch Antenna” ELECTRONICS LETTERS 29th September 2005 Vol. 41 No. 20 [13]Madhur Deo Upadhayay1, A.Basu2, S.K.Koul3 and Mahesh P. Abegaonkar4,”Dual Port ASA for Frequency Switchable Active Antenna” 978-1-4244-2802-1/09/$25.00 ©2009 IEEE, pp.2722-2725 [14] R.Chair, K.F. Lee,K.M.Luk “Bandwidth and cross-polarisation characteristics of quarter wave shorted patch antenna” microwave and op.technol.Latt,vol-22 no 2,pp.101-103,1999 [15]N. Zhang, P. Li, B. Liu, X.W. Shi and Y.J. Wang “Dual-band and low cross-polarisation printed dipole antenna with L-slot and tapered structure for WLAN applications” ELECTRONICS LETTERS 17th March 2011 Vol. 47 No. 6 [16]Xue-jie Liaa, Hang-chun Yang and Na Han “AN IMPROVED DUAL BAND-NOTCHED UWB ANTENNA WITH A PARASITIC STRIP AND A

DEFECTED GROUND PLANE” 2010 International Symposium on Intelligent Signal Processing and Communication Systems (lSPACS 2010) December 6-8,2010, 978-1-4244-7371-7/10/$26.00 ©2010 IEEE [17] Hsing-Yi Chen and Yu Tao “Performance Improvement of a U-Slot Patch Antenna Using a Dual-Band Frequency Selective Surface With Modified Jerusalem Cross Elements” IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 59, NO. 9, SEPTEMBER 2011,pp 3482-3486 [18]Hsing-Yi Chen and Yu Tao “Antenna Gain and Bandwidth Enhancement Using Frequency Selective Surface with Double Rectangular Ring Elements” 978-1-4244-6908-6/10/201 0 IEEE, pp. 271-274 [19]S. Pinhas and S. Shtrikman, “Comparison between computed and measured bandwidth of quarter-wave microstrip radiators,” IEEE Trans.Antennas Propag., vol. 36, no. 11, pp. 1615–1616, 1988. [20] R. Waterhouse, “Small microstrip patch antenna,” Electron. Lett., vol. 31, no. 8, pp. 604–605, 1995. [21] J. R. Games, A. J. Schuler, and R. F. Binham, “Reduction of antenna dimensions by dielectric loading,” Electron. Lett., vol. 10, pp. 263–265, 1974. [22] K. L. Wong and K. P. Yang, “Compact dual-frequency microstrip antenna with a pair of bent slots,” Electron. Lett., vol. 34, no. 3, pp. 225–226, 1998. [23] K. L. Wong and Y. F. Lin, “Small broadband rectangular microstrip antenna with chip-resistor loading,” Electron. Lett., vol. 33, no. 19, pp. 1593–1594, 1997. [24]Shynu S.V. #, Maria J. Roo Ons#, Max J. Ammann#, Sarah McCormack*, Brian Norton*” Dual Band a-Si:H Solar-Slot Antenna for 2.4/5.2GHz WLAN Applications”pp.408-410 [25]Ke-Ren Chen, Chow-Yen-Desmond Sim, Member, IEEE, and Jeen-Sheen Row “A Compact Monopole Antenna for Super Wideband Applications” IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. 10, 2011, pp. 488-491 [26]N.D. Trang, D.H. Lee and H.C. Park “ Compact printed CPW-fed monopole ultra-wideband antenna with triple subband notched characteristics “ELECTRONICS LETTERS 19th August 2010 Vol. 46 No. 17 [27]L. Y. Cai, G. Zeng, H. C. Yang“Compact Triple band Antenna for Bluetooth/WiMAX/WLAN Applications” Proceedings of International Symposium on Signals, Systems and Electronics (ISSSE2010) [28] Zhi-Qiang Li, Chang-Li Ruan “a small integrated Bluetooth and UWB antennas with WLAN band notched characteristics”, proceedings of ISSSE 2010. [29]Mohamed H. Al Sharkawy “MINIATURIZED WIDEBAND SLOTTED MONOPOLE ANTENNA FOR WLAN APPLICATIONS” (c) 2010-IEEE APS, Middle East Conference on Antennas and Propagation (MECAP),Cairo, Egypt, 20.10.2010 [30]L.Y. Cai, Y. Li, G. Zeng and H.C. Yang “Compact wideband antenna with double-fed structure having band-notched characteristics” ELECTRONICS LETTERS 11th November 2010 Vol. 46 No. 23

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10. Authors Biography:

Govardhani. Immadi working as Associate

professor in KL University. Completed B.Tech in

KLCE affiliated to Acharya Nagarjuna University

in 2004. Received Masters degree from the Acharya

Nagarjuna University as a University topper in

2009.Major area of working is micro strip

antennas, electrically small antennas.

Venkata Narayana.M working as Associate

professor in KLUniversity,HODSED-1(ECE).

Completed B.Tech in 2001 in Bapatla Engineering

College affiliated to Acharya Nagarjuna University.

Received Masters Degree from the Acharya

Nagarjuna University in 2009.Major area of

working is micro strip antennas, electrically small

antennas.

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ISSN:2249-5789