International Journal of Innovative Technology and Exploring Engineering (IJITEE)
ISSN: 2278-3075, Volume-9 Issue-1, November 2019
839
Published By:
Blue Eyes Intelligence Engineering
& Sciences Publication
Retrieval Number: A4346119119/2019©BEIESP
DOI: 10.35940/ijitee.A4346.119119
Abstract-- This paper emphasizes the design of Sierpinski carpet
fractal antenna to miniaturize the antenna array of UHF Spaced
antenna Wind profiler radar that operates at 445 MHz. The
proposed antenna is designed using High Frequency Structure
Simulator (HFSS) where aluminium is used as a patch and
ground with air as dielectric substrate due to it’s zero loss tangent
.patch is separated from ground with help of hinges and fed with
50 ohm coaxial probe. The Sierpinski fractal antenna is designed
till third iteration so as to reduce its size and weight by 33 percent.
Keywords: Sierpinski carpet, fractal antenna, wind profiler
Radar, HFSS, UHF.
I. INTRODUCTION
In the last decade there has been an immense requirement
for the design of antennas in crucial sectors like military,
remote sensing, biomedical and telecommunication. In
general, the designation of antenna consists of certain
characteristics which comprises of compact size, low profile,
conformal and multiband. There are vivid approaches that has
come all through on the antenna design characteristics.
Lately, the described characteristics of an antenna can be
achieved by using properties of fractal[1][2].
Atmospheric Radars are useful for identifying
meteorological changes and weather forecasting. UHF
Spaced Antenna Wind Profiler Radar is a one of the type of
Atmospheric Radars, which is remote sensing instrument for
finding wind velocity components (U, V, W) at different
height levels from 0.3 Km to 4 Km with height resolution of
75 m.
Wind profilers working depends on occurring irregularities
in refractive index of atmosphere due to variations in
Temperature, pressure and humidity of atmosphere [3].
Parameters of Wind profiler Radar are given in Table I.
Revised Manuscript Received on November 06, 2019.
Elluru Jayapal, Department of Electronics and Communication
Engineering, S. V. University College of Engineering, Tirupati,A.P ,India
Email: jaijrfscholar@gmail.com
S. Varadarajan, Professor, Department of Electronics and
Communication Engineering, S. V. University College of Engineering,
Tirupati, A.P, India.
Table I : Wind profiler Radar Specifications
Operating frequency 445MHz
Technique Spaced Antenna with
3 receive channels
Antenna Sub-Array 18 element Hexagonal Shaped
Rectangular Patch Array
Transmit Antenna Array 3 Sub-Arrays (combined)
Receive Sub-Arrays 3 Sub-Arrays (independent Channels)
Transmit Peak Power 4 KW
Pulse width 0.5 to 8 micro seconds
Duty Ratio 10%
Reception 3 Channel Receiver
Radar Control PC-Based with GUI
Height Coverage 0.3 to 4 Km
Height resolution 75m
Transmit Array Gain 24.8 dBi
Receiver Array Gain 19 dBi
Data outputs SNR, U,V,W
Fig. 1: Three Sub-array for Wind profiler Radar
The Spaced Antenna (SA) technique gives better time
resolution over Doppler beam steering(DBS) method due to
the beam is pointed in zenith direction only where as DBS
method requires at least three beams which are pointed in
different directions. Vertical velocity of wind is calculated
with help of Doppler Shift, while horizontal velocity of wind
is found by using Spaced Antenna Technique [4]. More
recently, UHF Spaced Antenna wind profiler Radar has been
developed at Sri Venkateswara University, Tirupati, with the
help of Spaced Antenna technique to measure velocities of
atmospheric wind. The Antenna used in Wind profiler Radar
is a three Sub-arrays with each array consists of eighteen
elements linearly polarized Rectangular microstrip patch
antenna in hexagonal shaped
array, as shown in Fig.1.
Design and Analysis of Sierpinski Carpet Fractal
Antenna for UHF Spaced Antenna Wind Profiler
Radar
Elluru Jayapal, S. Varadarajan