Study and Design of Dual Frequency High Gain and...

Study and Design of Dual Frequency High Gain

and Conformal Microstrip Patch Antenna

S. Aruna1, K. Srinivasa Naik2, J. Ramesh2 and D. Madhu2

1Andhra University College of Engineering (A),

Visakhapatnam-530 003, A.P

email:[email protected] 2Vignan's Institute of Information Technology,

Duvvada, Visakhapatnam, Andhra Pradesh.

email:[email protected]

Abstract. Patch antennas are currently under contemplation for use in multi

band communication systems and high gain applications due to their captivating

characteristic, such as low profile, unidirectional radiation patterns, conformal

nature and ease of fabrication. In order to increase the bandwidth, dual band

operation the patches can be designed in a variety of shapes. The main goal of

this work is the design of Dual frequency high gain conformal antenna array

mounted on a surface of the cylinder at 2.45GHz and 2.05GHz. The designed

antenna array is acquired by providing equal square slots at the opposite corners

of the rectangular patch antenna in Dual-band operation with good impedance

matching and high gain is acquired by antenna array structure. Conformal

antenna is designed to conform or follow some recommended shape which is

mounted on a curved surface structure. The designed antenna is simulated and

optimized by Using High Frequency Structure Simulator (HFSS) which can be

used in aircrafts, missiles etc.

Keywords: Conformal; Dual frequency; slots; multi band; high gain; antenna

array; high frequency structure simulator(HFSS).

1 Introduction

Micro-strip patch antenna plays very important role in the various communication

systems [1] because of numerous benefits, such as the small size, light weight, thin

profile, low cost. However, it also has the imperfection of the narrow frequency

bandwidth and large dielectric loss, so a lot of research has been made to enlarge

micro-strip antenna bandwidth and better the antenna gain. Therefore this method is

mainly concerted in the following cases:

(1) Considering the dielectric substrate thickness.

(2) Considering the substrate which having low dielectric constant.

(3) Considering the layout of patch [2].

(4) Considering non-planar patch Antenna layout

Advanced Science and Technology Letters Vol.147 (SMART DSC-2017), pp.236-243

http://dx.doi.org/10.14257/astl.2017.147.33

ISSN: 2287-1233 ASTL Copyright © 2017 SERSC

In general the gain of the single micro-strip patch antenna having gain 6~8dB. A

Microstrip radiating elements are used often used to consist of micro-strip array

elements in order to attain a larger gain or specific directivity.

Conformal antennas obtained great interest, as crafting of antenna on structures

targets the problem of the radiation from smooth convex objects, by using conformal

antenna array the field view can be extended up to 3600. The concept of conformal

antenna most importantly found in the smart skin approach method, which demands

the inclusion of non-planar active antennas in curved surfaces adapted to the skin of

the platforms like aerospace applications missiles, vehicles etc.[8] Conformal

antennas on some curved surface, have their shapes resolved by some specific EM

properties[10] such as antenna beam shape, beam width, bandwidth or angular

coverage. The micro-strip antennas are conformal in nature and hence they can be

used simply on any curved surface by just changing the shape of the antenna ground

plane. If the ground plate and substrate is made conformal then the patch can also be

wrapped on it as MSA and it can be realized with the same transmission model

equations used for planar antenna [6], without getting any unacceptable changes in its

radiation characteristics.

There are various feeding methods that can be used for feed Micro-strip patch

antenna design. The most commonly used feeding methods are [3]: 1.Micro-strip feed

line; 2.Coaxial probe feed; 3.Aperture coupling; 4. Proximity coupling. Micro-strip

feed line feeding is used in this designing.

2 Realization of Antenna Parameters

A single MSA is designed on HFSS 3D simulation tool, which configure the base for

designing of conformal antenna. For establishing patch dimensions first a theoretical

design has to be done by [7] specifying dielectric constant, Frequency of operation

and thickness of substrate to be taken:

For Effective radiation, patch width is calculated as :

0

12

2

r

cw

f

Where c is the velocity of light in free space.

(1)

2. Formula for effective dielectric constant of MSA,

1

21 11 12

2 2

r r

eff

h

w

where W/h >1

(2)

3. For calculation of length extension,

Advanced Science and Technology Letters Vol.147 (SMART DSC-2017)

Copyright © 2017 SERSC 237

0.3 0.264

0.412

0.258 0.8

r

r

h

wL h

h

w

(3)

4. For dominant mode, the resonant frequency is given as:

02eff

eff

cL

f

(4)

0

2 r

vF

L

(5)

2L Leff L (6)

3 Dual Frequency Patch Antenna

For Dual band performance two square slots at equal corners of MSA are introduced. Square slot width and length are attained by trial and error method for a specified new

band of frequency.

𝑤1= 9mm, 𝐿1= 10mm

Substrate is Rogers RT/duroid 5880, Resonant frequencies are 2.45GHz &

2.05GHz, Radiation box at λ/4 distance from antenna should be taken.

Fig. 1. Antenna unit structure


238 Copyright © 2017 SERSC

Fig. 2. Designed model of MSA

4 Dual Frequency Linear Array Patch Antenna

A 4-element linear array with equal spacing is designed by using HFSS. The linear

array antenna [9] is formed as shown in below. Uniform spacing of 0.5λ, is taken

where λ is the resonating frequency corresponding wavelength, the resonating

frequency is 2.45 GHz. Array pattern gain reached is 13.95dB.

Patch antenna experiences many losses i.e. loss due to the feeders and adapter and

cable loss. That leads to 1 to 2 dB loss in the gain. VSWR of 1.68 & 1.7 was

observed. In most of the application a VSWR of 1.5 to 2 is required [5]. The second

important parameter of array is the beam width, which was required to be in the range

200 to300, whereas the experimental results show a beam width of about 240.

5 Dual Band Patch Antenna Conformed On Cylinder

The dual band corner cut Micro-strip Patch Antenna is mounted on the surface of the

cylinder of radius r and height h, as shown in Fig.1.

Fig. 3. Dual frequency antenna on surface of a cylinder (Conformal antenna)



6 Simulated Results



Table 1. Optimized antenna parameters

Micro-strip patch antenna Dimension after parametric analysis(in mm)

Patch antenna

Width 45

Length 48

Quarter wave transformer

Width 0.822

Length 20.94

Transmission Feed line

Width 3.059

Length 40.8805

7 Conclusion

The rectangular narrow band patch antenna is transmitted into the Dual band patch

antenna by creating cut-down squares at symmetrical corners therefore the band of

operation is increased and also by optimizing antenna parameters the unit gain value



obtained is 7.57dB, the maximum gain of 13.95dB is obtained by 4- element array,

therefore the antenna and array have the very good radiation performance and

increased band of operation Also planar Micro-strip antenna is conformed on

cylindrical surface by ANSOFT HFSS wrapping method, which is one of the

advanced antenna design technique nowadays. Thus Micro-strip patch antennas are

low profile and yet the most utilizable form of antennas.

References

1. Zhong Shishun. “The theory of micro-strip antenna and application” Xian_The

Publishing House of XIDIAN University_1991_5-39.

2. Y X Guo_K M Luk_K F Lee.” A dual-band patch antenna with two U-shaped slots”[J].

Microwave and Optical Technology Letters2000_26(2).

3. Keith R. Carver, James W. Mink, “Microstrip Antenna Technology”, IEEE Transactions

on Antennas & Propagation, Vol-29, No. 1, January 1981.

4. Lars Josefsson and Patrik Persson, Conformal Array Antenna Theory And Design, The

IEEE Press series on electromagnetic wave theory, 2006.

5. R. J. Mailloux, J. Mcllvenna and N. Kernweis "Microstrip array technology", IEEE Trans.

Antennas Propagat., vol. AP-29, no. 1, pp.25 -38 1981.

6. Constantine A. Balanis, “Antenna Theory Analysis and Design”, Wiley Publications,

2005.

7. ‘Modern Antenna Design”, Thomas A. Milligan, IEEE Press, John Wiley & sons

Publications © 2005.

8. K. Srinivasa naik and S. Aruna, “Investigation On the generation of pattern for Marine

Radar Applications”, in Indian Journal of Science and Technology(INDJST), vol 9(7),

84169, pp, 1-7, Februvary 2016.

9. P. V. Hema Latha, S. Aruna and K. Srinivasa Naik, “Analytical analysis of 8-element ring

Width rectangular microstrip patch antenna Array”, International Organisation of

Scientific Research [IOSR], volume 11, Issue 5, ver, III (sep.-oct, 2016, pp 34-42.

10. “Generation of Radiation patterns for triangular on pedestal of distributions” Asian

Academic research Journal of Multidisplinary (AARJMD)ISSN:23192801, volume 3,

Issue4, (April 2016), page:43-55, (Authors: S. Aruna, Dr. G. S. N Raju and Dr. P. Sri

Devi.



Study and Design of Dual Frequency High Gain and...

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