DESIGN OF A SELF SIMILAR MULTI FRACTAL CANTOR ANTENNA FOR IRNSS &GAGAN APPLICATIONS

OBJECTIVE

To design a Self similar Multifractal Cantor Antenna for

an user – receiver, which will be used concurrently for

IRNSS (Indian Regional Navigational Satellite

System) and GAGAN (GPS-Aided Geo-Augmented

Navigation) Applications.

To investigate the behavior of the proposed antenna by

means of its

parameters such as Return Loss and Radiation Pattern.

INTRODUCTION:- GPS is satellite based navigation system based on radio

navigation.

On considering the Indian scenario, there are so many

limitations of using GPS.

The main limitations are Selective Availability and Anti spoofing.

GPS alone cannot satisfy the integrity, accuracy and availability

requirements.

So GPS Aided and Geo Augmented Navigation (GAGAN), a

satellite based augmentation system for India, built over the

GPS system is expected to provide the seamless navigation

support over the Asia-Pacific regions.

Signals received by the GAGAN Receiver is having a

frequency band of L1

(1575.42MHz), L5 (1176.45MHz).

An innovative proposal based on a unique concept of using

geo-stationary

satellite for navigation applications is being implemented

for India

The system is named as IRNSS (Indian Regional

Navigational Satellite

System), a regional self-reliant, all weather, 24 hour

navigation support

system over the Indian region’s land, air and sea users.

IRNSS is an autonomous regional satellite navigation

system being

developed by the Indian Space Research Organization

which would be

under total control of Indian government.

The requirement of such a navigation system is driven by

the fact that

provides access to Global Navigation Satellite Systems

since GPS is not

guaranteed in hostile situations.

Contd..

The IRNSS would provide two services.

One with the Standard Positioning Service open for civilian

use and the

other service is the Restricted Service, encrypted one for

authorized users

(military).

IRNSS consist of a constellation of seven satellites and a

support ground

segment. Three of the satellites in the constellation will be

placed in

geostationary orbit.

With the advent of IRNSS, India will be able to have a self-

reliant navigation

with entire control and operations over Indian region.

IRNSS signals consist of a Special Positioning Service and a

Precision

Service.

Both will be carried on L5 (1176.45 MHz) and S band

(2492.08 MHz)

Design of IRNSS antenna at user segment is necessary.

Contd..

For the applications of IRNSS and GAGAN, an user

receiver with Multiband Antenna is required.

This Project emphasize on a Circularly polarized

multifractal Cantor antenna.

The self similar property in antenna exhibits multiband

resonant frequencies.

Multifractal cantor is mainly meant for Miniaturization

A fractal is a rough or fragmented geometric shape

that can be split into parts, each of which is (at least

approximately) a reduced-size copy of the whole, and

this property is called self-similarity.

Contd..

Because of the self similar characteristics, fractal concepts have emerged as a novel design methodology for compact multiband antennas

The geometry of the proposed antenna is based on the geometry of Cantor set. A Cantor set is a self-similar object which is formed by an iterative process starting with initiator of length and width .

The Operating frequencies for this antenna will operate at 1176.45MHz(L5), 2492.08MHz(S ) ,1575.42MHz(L1).

Advanced Design System Software will be used for

simulation and expected Result.

Contd..

User Segment of IRNSS

• The user segment consists of IRNSS receivers

operating in

– Single Frequency ( L5 or S band)

– Dual Frequency (L5 and S band)

• Single frequency and dual frequency receivers shall

receive both SPS and RS signals. SPS is for civilian

users.

Paper title A Multifractal Cantor Antenna for MultibandWireless Applications

Author B. Manimegalai, S. Raju

Paper/journal IEEE Antennas And Wireless Propagation

Letters,

Vol. 8

Year 2009

Summary A novel printed Cantor fractal monopole antennausing multifractal technique is proposed.

Conclusion The antenna has multi-band characteristics

covering GSM, DCS, PCS, UMTS, and

WLAN applications.The multifractal Cantor antenna offers the possibility of miniaturization.

LITERATURE SURVEY-1

Paper title A Self-Similar Fractal Cantor Antenna for MICS Band Wireless Applications

Author Gopalakrishnan Srivatsun, Sundaresan Subha Rani

Paper/journal Wireless Engineering and Technology, 2,

107-111

Year 2011

Summary A Self-similar fractal antenna using multi cantor technique is proposed and experimentally studied.

Conclusion Space-filling cantors and self-similarity properties of fractal geometry have been adopted in the proposed antenna to miniaturize the size of antenna. The antenna is designed in such a way to operate at MICS band (Medical Implant communication Service) for wireless telemedicine application

LITERATURE SURVEY-2

Paper title A Compact Multiband Fractal Cantor Antenna forWireless Applications

Author G. Srivatsun, Subha Rani

Paper/journal European Journal of Scientific ResearchISSN 1450-216X Vol.71 No.2 , pp. 273-282

Year 2012

Summary This paper addresses the appraisal of the novel self-similar fractal geometry to miniaturize and to resonate for multiband frequencies.

Conclusion A compact antenna designed at 2.4GHz exhibiting multiband characteristics which tends to fit WLAN IEEE 802.11b and IEEE802.15, PCS(1900), GSM lowerband, GSM higher band, DCS(1800),IMT(2000), UMTS(2100), WiFi, and WLAN wireless applications has been proposed.

LITERATURE SURVEY-3

Paper title Improved Multiband performance with

self similar fractal antennas

Author D.Anagnostou , M.T.Chryssomallis

Paper/journal IEEE transactions on antennas &

Propagation.

Year 2003

Summary Fractal Antennas have the characteristic of

radiating in multiple frequencies, usually

in a logarithmic pattern, through the

property of self similarity.

Conclusion 7 Controllable frequency bands from 0 to 2

GHz with one antenna are obtained. A new

approach to multiple frequency antenna.

LITERATURE SURVEY-4

Paper title Broad Band Dual frequency Microstrip

Patch Antenna With Modified Sierpinski

Fractal Geometry

Author Jaume Anguera ,Carles Puente

Paper/journal IEEE transactions on antennas &

Propagation.

Year 2004

Summary A dual frequency antenna based on the

sierpinski fractal with two parasitic

patches to enhance the impedance

bandwidth

Conclusion A physical interpretation of the input

impedance enhancement has been

demonstrated using an electrical circuit

model based on RLC resonators

LITERATURE SURVEY-5

Paper title A Modified Sierpinski Fractal Antenna for

Multiband Application

Author Kuem C.Hwang

Paper/journal IEEE transactions on antennas &

Propagation.

Year 2007

Summary A Broadband planar Sierpinski fractal

antenna for multiband application(

GSM/PCS/SATELLITE DMB)

Conclusion A modified two iteration Sierpinski patch

and a slotted ground plane are used to

enhance the bandwidth performance.

LITERATURE SURVEY-6

Paper title Spiral Antenna Array Using RT-Duroid

Substrate for Indian Regional Navigational

Satellite System

Author B.SadasivaRao ,T.Raghavendra Vishnu

Paper/journal International Journal Of Soft Computing

And Engineering

Year 2012

Summary A new planar wideband feed for a slot

spiral Antenna is designed for IRNSS

Conclusion Designed antenna will perform over the

frequency L5(1175 MHz).Spiral antenna is

able to receive upper hemisphere satellite

signals.

LITERATURE SURVEY-7

Inference From Literature Survey

From the literature survey it is observed that multi fractal Cantor

antenna can be used for multiband behavior.

Using fractal Cantor antenna, miniaturization is Obtained

PROPOSED ANTENNA STRUCTURE

PROPOSED SYSTEM STEPS INVOLVED:

STEP 1 : The Self similar fractal structures are constructed by scaling a

rectangle.

STEP 2 : Scaling is done by a factor of three along its x and y coordinates.

STEP 3 : Factoring three along its length and width leads to nine rectangles

measure equal in dimension

STEP 4 : The left and right columns are eliminated except the middle region

STEP 5 : This process is a repetitive procedure and continued upto n th iteration

and placing. Placing port over designed layer.

STEP 6 : Changing the port positions and analyzing the changes occurring.

STEP 7 : Validating the results

The self similar structure segments are developed at each iteration of same dimensions.

The obtained antenna tends to diminish in size and occupies fewer spaces. The self similar Cantor fractal antenna is developed on a FR4 substrate with a thickness of 1.6mm.

Ground plane is placed at the bottom of the substrate.

Using the self similarity property the fractal dimension of set S(w) have nine subsets.

For the first iteration the 1st, 3rd , 4th , 6th subsets are removed. Likewise the iteration goes up for the remaining subsets. The iterative coefficients are obtained as follows

DESIGN SPECIFICATIONS

Substrate used – FR4

Substrate Thickness – 1.6mm

Conductor – Copper (35micron)

The cantor fractal antenna is designed in ADS layout window.

Initially with the specified dimensions and based upon the iterative coefficients obtained the cantor fractal antenna is designed in the layout window.

Using the polygon structure the cantor fractal geometry is generated and the process is repeated for each sub segment.

Once the antenna is designed in the layout window, the next step is to specify the substrate properties. FR4 substrate is chosen and the thickness is specified.

The performance of the multifractal cantor antenna at different iteration has been investigated using ADS momentum.

Optimization of port position is done for obtaining the corresponding frequencies.Each frequency the radiation pattern and the return loss plot are developed and analyzed.

Designed Antenna Layout in ADS

Designed Antenna Layout in ADS

Designed Antenna Layout in ADS

Designed Antenna Layout in ADS

Basic Properties of fractals

Fractals have definite cantor even at small scales.

It is self-similar and space filling cantor.

It has fractal dimension and are recursive in nature.

They are irregular to describe in mathematical geometry.

This Project aims at regular self-similar cantor

Substrate Editor view

SUBSTRATES USED PORT POSITIONS FREQUENCY RETURN LOSS(dB)

X Y

FR4-1.6mm 109 174 1.17 GHz2.2GHZ

-10-24

FR4-1.6mm 112 174 1.3GHz1.42GHz2.5GHZ

-18-20-24

FR4-1.6mm 115.6 174 1.176GHz1.575GHz2.492GHz

-6-13-17

FR4-1.6mm 114.3 174 1.05GHz1.35GHz2.53HGz

-20-17

FR4-1.6mm 116 174 1.125GHZ1.495GHz2.345GHz

-15-18-10

Various port Positions and Substrate used

Simulation Results- Return Loss plot

Current Distribution

Radiation pattern of Cantor Antenna

Prototype of Self Similar Cantor Antenna

Obtained Antenna Parameters:-

CONCLUSION

The design of Cantor fractal antenna that effectively supports multiband operation is proposed.

The Cantor fractal antenna is designed up to two iterations

The desired results are obtained for Single layer substrate.

The experimental data clearly depicts the antenna’s multiband operation.

The designed antenna is showing remarkable performance over the frequencies 1176.45MHz, 1575.42MHz, 2492.08MHz.

Thus an multiband antenna with miniaturized size is designed which can be used concurrently for IRNSS and GAGAN user receiver applications.

The designed antenna shows good gain and directivity.

REFERENCES:-

1. Gopalakrishnan Srivatsun, Sundaresan Subha Rani, “A Self-Similar Fractal Cantor Antenna for MICS Band Wireless Applications” Wireless Engineering and Technology, 2011, 2, 107-111

2. B. Manimegalai, S. Raju, “A Multifractal Cantor Antenna for Multiband Wireless Applications” IEEE Antennas And Wireless Propagation Letters, Vol. 8, 2009

3. B.Sada siva Rao,T.Ragavendra Vishnu, “ Spiral Antenna Array Using RT-Duroid

Substrate for IRNSS ”, International Journal of soft computing and Engineering,

May 2012.

4. K.N.Suryanarayana Rao “ GAGAN-The Indian Satellite based augmentation

system”, ISRO Satellite Centre, May 2007.

5. G. Srivatsun, Subha Rani, “A Compact Multiband Fractal Cantor Antenna for Wireless Applications” European Journal of Scientific Research ISSN 1450-216X Vol.71 No.2 (2012), pp. 273-282

6. Shinya TADA ,Ridho Chayano,yuichi Kimura , “ A consideration On radiation

properties of multiband Sierpinski Gasket Microstrip Antenna ” , Proceedings of

ISAP’o4 sendai , Japan.

7. Kuem.C.Hwang, “ A modified Sierpinski Fractal Antenna for Multiband

Application” , IEEE Antennas And wireless propagation letters ,VOL.6,2007.

8. Jaume Anguera ,Enrique Martinez , “ Broad Band Dual-Frequency Microstrip

Patch Antenna with Modified Sierpinski Fractal Geometry” , IEEE Transactions

on Antennas and Propagation, vol .52,No.1 January 2004.

9. Jordi Romeo And Jordi Soler, “ Generalized Sierpinski Fractal Multiband

Antenna”, IEEE Transactions on Antennas and Propagation, vol .49,No.8 August

2001.

10. Carles puente-Baliarda, Jordi Romeu,” On the behavior of the Sierpinski

Multiband Fractal Antenna”, IEEE Transactions on Antennas and

Propagation, vol .46,No.1 April 1998.

11. R.L.yadava, M.Ram ,” Multiband Triangular Frcatal Antenna for mobile

communications”, International Journal Of Engineering Science and

Technology

Publication Proof:- A paper titled “DESIGN AND SIMULATION OF A SELF SIMILAR MULTI FRACTAL CANTOR ANTENNA FOR GAGAN & IRNSS APPLICATIONS” has been submitted to the journal “Wireless Personal Communications”.

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