=Paper=
{{Paper
|id=Vol-3058/paper27
|storemode=property
|title=Coaxial Probe Fed Fractal Patch Antenna For Wireless Application
|pdfUrl=https://ceur-ws.org/Vol-3058/Paper-049.pdf
|volume=Vol-3058
|authors=Yadwinder Kumar,Nisha
}}
==Coaxial Probe Fed Fractal Patch Antenna For Wireless Application==
https://ceur-ws.org/Vol-3058/Paper-049.pdf
Coaxial Probe Fed Fractal Patch Antenna for Wireless
Application
Yadwinder Kumar1 and Nisha2
1,2
E.C.E Department, YCOE (Punjabi University) Talwandi Sabo, Punjab, India
Abstract
A planar microstrip patch antenna has been designed by amalgamating two different fractal
geometries in the form of notches and cuts capable of exhibiting heptaband behavior inherited
by basic fractal shapes. The suggested layout reverberate at heptad frequencies and exhibits
bandwidth of 300 MHz, 110 MHz, 200 MHz, 160 MHz, 300 MHz, 300 MHz and 120 MHz
respectively. Entire reverberant frequencies have admissible numbers of S11 and VSWR less
than 2. The proposed structure has been designed on rectangular FR4 substrate with a square
patch dimensions of 45 mm × 45 mm. Proposed antenna structure is compact and can become
part of portable device. Design, analysis and simulation have been done on an electromagnetic
simulator.
Keywords *
Hybrid fractal, Minkowski, Koch, FR4.
1. Introduction
Microstrip antennas are widely used in handheld applications. They are popular due to their easy
availability, low cost and ease of fabrication on substrates. The radiating structure is a metal patch of
different shapes which is placed over a ground plane [1]. The microstrip patch can be of any shape but
square, rectangular, circular, elliptical and ring shapes are most common ones. It has a conducting
layers on both sides or one side of a substrate.
Figure 1. (a) Koch fractal and its iterations (b) Minkowski fractal and its iterations
The key attributes of a microstrip antennas are lightweight, smaller size and volume, low cost, and
bulk production capability [2][3]. Traditionally, a single antenna was designed to operate at a one or
two frequencies, so more than one antennas were required for various applications [4]. Such
limitations has were overcome by use of fractal shapes. Fractal shapes were initially explained by
Mandelbrot in 1983. Such layouts has distinctive spatial appearances [5]. In modern wireless
International Conference on Emerging Technologies: AI, IoT, and CPS for Science & Technology Applications, September 06–07, 2021,
NITTTR Chandigarh, India
EMAIL: : yaddi79@gmail.com (A. 1); nishapuri1992@gmail.com (A. 2)
ORCID: 0000-0003-2938-0329 (A.1); Not Available (A. 2)
©2021 Copyright for this paper by its authors.
Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0).
CEUR Workshop Proceedings (CEUR-WS.org)
communication systems fractal antennas have fulfilled requirements of obtaining multiple resonances
by a single antenna. So multiband but low profile antennas are very popular for various wireless
applications [6][7].
The congruous architecture of Koch curve is straightforward. A Minkowski fractal is also a well
known fractal geometry, due to its space filling properties it can be used to impoverish the form factor
of the layout by increasing the efficiency with which extended electrical length [8]. Both the fractal
curves are shown in Figure 1.
2. Antenna Design
The proposed structure starts with a square microstrip patch of 45 mm × 45 mm designed on FR4
substrate measuring 56 mm × 54 mm in HFSS electromagnetic field solver.
Figure 2. Square shaped microstrip patch used as an initiator
The following mathematical expressions [9] are used for calculation of various antenna
geometrical parameters:
C
W= (1)
εr +1
2 f0
2
1
−
ε + 1 ε r −1 h 2
ε eff = r + 1 + 12 (2)
2 2 w
c
Leff = (3)
2 f 0 ε eff
+ 0.3) + 0.264
(ε w
eff
∆L = 0.412h h (4)
(ε eff − 0.258) w + 0.8
h
L = Leff − 2∆L (5)
The designed microstrip patch antenna is shown in figure 2 has been simulated in its basic form
and results were extracted. The coaxial feeding method and a simulated SMA connector was utilized
for this antenna geometry. Full ground has been used at the back of the substrate.
The calculated design criteria of the suggested layout are shown in Table 1.
Table 1
Dimensions of suggested layout
Parameters Values (mm)
Patch layout 45 × 45
Ground layout 56 × 56
Feeding technique used Coaxial feed
Substrate used FR4
The next step in designing the proposed structure is by removing the patch material in the form of
Koch fractal and Minkowski fractal from the lower and upper side of the patch at 1st iteration. After
simulating this structure with coaxial probe feed, resonance has been achieved at four different
frequencies 3.1GHz, 4.4GHz, 6.1GHz and 7GHz with good values of return loss. Later iteration level
has been increased up to 2nd level. Multiband resonance has been achieved due to the self-similar
behavior of the fractal structures which generates a lot of edges, corners, segments and perimeter
[8][10][11]. The proposed hybrid fractal antenna design after 1st and 2nd iteration are shown in
Figure3.
(a) (b)
Figure 3. Final proposed hybrid fractal antenna with Koch and Minkowski fractal design (a) for 1st
Iteration and (b) for 2nd iteration
3. Outcome
Present portion portrays the analogizing and analysis of profuse outcome from the simulation of
proposed antenna structure in the electromagnetic simulator. As mentioned in the prior section
proposed antenna has been designed for iterations 1 and 2. A comparison of the reflection coefficient
properties of the designed layout as demonstrated below .
Figure 4 Comparison of return loss for the patch after 1st & 2nd iteration
For the simple square patch the structure resonates at two frequencies. The suggested layout
structure reverberates at four un-identical frequencies at 1st iteration while it reverberates at 7
different frequencies for 2nd iteration. It has been noticed that suggested layout is compact and
multiband radiating device. Table 2 displays the elaborated values of reverberate frequencies inclusive
of VSWR and bandwidth. All obtained values are in an acceptable range.
Table 2
Various units of the suggested layout
Resonating Frequency Return Loss (dB) Bandwidth
Sr. No. VSWR
(GHz) (MHz)
1. 2.8 20.1 1.21 300
2. 3.2 14 1.49 110
3. 4.5 11 1.85 200
4. 6.0 20 1.23 160
5. 7.5 19 1.25 300
6. 8.2 26.5 1.09 300
7. 9.6 32 1.05 120
Emission figure is a kind of diagrammatic illustration of dissimilarity in the field strength of the
radio waves in two-dimensional stretch. Two dimensional radiation designs are more often taken at
particular frequency, selected polarization and at particular plane.
Figure 5. (a–g) shows the simulated 2-D far field radiation patterns for each reverberate frequency.
Red color lines represents the values for phi = 0o and blue color lines for theta = 90o in the elevation
plane.
Figure 5. 2D radiation graph (a) 2.8 GHz (b) 7.5 MHz (c) 8.2 GHz (d) 9.6 GHz (e) 6 GHz (f) 3.2 GHz (g)
4.5 GHz
4. Conclusion
In this work, a hybrid fractal microstrip patch antenna has been designed by using Koch and
Minkowski fractal structures. The proposed antenna has been designed on FR4 material. Probe fed
coaxial feed has been used for providing signal. Simulation is done on the HFFS electromagnetic
simulator and resonance has been obtained at seven different frequencies in gigahertz are 2.8, 3.2, 4.5,
6.0, 7.5, 8.2 and 9.6 with sustainable values of return loss in decibels 20.1, 14, 11, 20, 19, 26.5, 32
respectively. Suggested layout is close packed and suitable for wireless applications.
5. References
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Progress In Electromagnetics Research C, vol. 2, pp. 7–12, 2008.
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Electronics Letters, vol. 45, no. 15, p. 773, 2009.
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pp. 3–6, 1996.
[4] L. Lizzi, R. Azaro, G. Oliveri, and A. Massa, “Multiband Fractal Antenna for Wireless
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[5] D. H. Werner and S. Ganguly, “An overview of fractal antenna engineering research,”
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441–453, Sep. 2017.
[8] Y. K. Choukiker, S. K. Sharma, and S. K. Behera, “Hybrid fractal shape planar
monopole antenna covering multiband wireless communications with MIMO
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Propagation, vol. 62, no. 3, pp. 1483–1488, 2014.
[9] C. E. Balanis, Antenna Theory: Analysis and Design, 3rd Edition - Constantine A.
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[10] Wen-Ling Chen, Guang-Ming Wang, and Chen-Xin Zhang, “Small-Size Microstrip
Patch Antennas Combining Koch and Sierpinski Fractal-Shapes,” IEEE Antennas and
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[11] Y. Kumar and S. Singh, “A Compact Multiband Hybrid Fractal Antenna for
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