Session 3P3
Antenna Array Synthesis — Theory, Algorithms, and
Applications
A Pattern Synthesis Technique for Multiplicative Arrays
Herbert M. Aumann, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rectangular Thinned Array Design by McFarland Difference Sets
Giacomo Oliveri, Federico Caramanica, Paolo Rocca, Andrea Massa, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interleaved Array Antennas Design — (Almost) Deterministic Strategies
Massimiliano Simeoni, Ioan E. Lager, Cristian I. Coman, Christian Trampuz, . . . . . . . . . . . . . . . . . . . . .
Antenna Array Synthesis through Time Modulation
Lorenzo Poli, Paolo Rocca, Giacomo Oliveri, Leonardo Lizzi, Andrea Massa, . . . . . . . . . . . . . . . . . . . . . .
A Complete MIMO System Built on a Single RF Communication Ends
Vlasis Barousis, Athanasios G. Kanatas, George P. Efthymoglou, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Critical Wavenumbers in the Classification of Fractal Radiation Patterns
Giovanni Franco Crosta, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Artificial Magneto-superstrates for Gain and Efficiency Improvement of Microstrip Antenna Arrays
Hussein Attia, Omar F. Siddiqui, Omar M. Ramahi, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analytical Model to Compute the Far-field Radiation of Patch Antennas Arrays Loaded with
Metamaterial-superstrates
Hussein Attia, Omar F. Siddiqui, Omar M. Ramahi, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rectangular Ring Antenna for On-body Communication System
Norsiha Zainudin, Muhammad Ramlee Bin Kamarudin, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A New Fractal Antenna for Super Wideband Applications
Abolfazl Azari, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Koch Fractal Antenna for UWB Applications
Javad Rohani, Abolfazl Azari, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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A Pattern Synthesis Technique for Multiplicative Arrays
Herbert M. Aumann
MIT Lincoln Laboratory, Lexington, Massachusetts, USA
Abstract— A two-dimensional multiplicative phased array, such as a Mills Cross array [1],
is well known in radio astronomy for providing high angular resolution at low cost. When
compared to an N × M element planar phased array, a multiplicative array provides the same
null-to-null beamwidth with only N + M elements. Typically a multiplicative array consists of
two orthogonal linear arrays with coincident phase centers. A conventional fan beam is formed
by each linear array. The two beams are then cross-correlated to generate a multiplicative array
pattern. Multiplicative arrays with uniform excitation have sidelobes that are 6 dB higher than
those of a planar array with uniform illumination. MacPhie [2] showed that the power pattern
of a multiplicative array pattern can be made to match the power pattern of a planar array with
uniform excitation.
In this presentation we generalize the power pattern technique. We will prove that an excitation
function for the multiplicative array can be synthesized so that its power pattern is identical in
every respect to a planar array pattern with an arbitrary excitation, provided that the planar
array excitation is separable. It is shown that the excitation of each linear array of the multiplicative array has to be the auto-correlation of the excitation along the corresponding major axis of
the planar array. The latter excitation can be obtained from any conventional pattern synthesis
technique. Thus, a multiplicative array can match with 2(N + M − 1) elements the beamwidth
and sidelobes of the N × M element planar array. The result is illustrated by the excitation
function required to implement a two-dimensional 30 dB Chebyshev taper with a multiplicative
array.
REFERENCES
1. Mills, B. Y. and A. G. Little, “A high resolution aerial system of a new type,” Australian J.
of Phys., Vol. 6, 272–278, 1953.
2. MacPhie, R. H., “A mill cross multiplicative array with the power pattern of a conventional
planar array,” Proceedings of the IEEE Antennas and Propagation Society Int. Symposium,
1064–1076, Charleston, North Carolina, USA, July 2008.
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Rectangular Thinned Array Design by McFarland Difference Sets
G. Oliveri, F. Caramanica, P. Rocca, and A. Massa
ELEDIA Research Group at DISI, University of Trento, via Sommarive 14, I-38123, Trento, Italy
Abstract— The problem of reducing the number of elements of large arrays is of great importance in satellite, remote sensing, radar and biomedical imaging applications in which the cost,
weight, power consumption, mutual coupling effects, HW and SW complexity have to be as low
as possible. Thinned arrays, however, are known to exhibit high peak sidelobe levels (PSL) if not
suitably designed [1]. As a consequence, design techniques able to control and reduce the PSL of
non-regular arrays have been subject of research since their introduction [1–5].
Random designs were among the first methodologies to be applied, due to their simplicity and
their good performances [1]. Such approaches have been overcome only by the introduction of
stochastic optimization techniques [1], which, however, can be computationally unfeasible for
very large arrays, and do not allow a-priori estimate of their performances [1]. More recently,
an innovative deterministic technique able to provide good and predictable performances with
very low computational efforts has been proposed for the thinning of large arrays [1]. Such
technique, which exploits the two-level autocorrelation function of binary sequences derived by
difference sets (DSs), has been shown to provide predictable advantages in terms of PSL with
respect to the corresponding random designs, both for linear and for square and almost-square
designs [1]. Moreover, an extension of such an approach, based on Almost Difference Sets, has
allowed its application in a significantly wider set of configurations [2, 3]. However, no rectangular
DS (or ADS) designs with very different resolutions in the two angular directions have been
investigated at present, despite the practical importance of such arrays in radar and remote
sensing applications.
In this paper, the performances of a new class of DS-based thinned arrays will be investigated.
The thinned geometries will be deduced by McFarland DSs [4], which are a class of non-cyclic
DSs defined over a p × p(p + 2) lattice (with p a prime number). The accuracy of the available
PSL estimators will be assessed by means of an extensive numerical validation, and comparisons
with state-of-the-art thinning techniques will be provided as well.
REFERENCES
1. Leeper, D. G., “Isophoric arrays-massively thinned phased arrays with well-controlled sidelobes,” IEEE Trans. Antennas Propagat., Vol. 47, No. 12, 1825–1835, Dec. 1999.
2. Oliveri, G., M. Donelli, and A. Massa, “Linear array thinning exploiting almost difference
sets,” IEEE Trans. Antennas Propagat., Vol. 57, No. 12, 3800–3812, Dec. 2009.
3. Oliveri, G., L. Manica, and A. Massa, “ADS-based guidelines for thinned planar arrays,” IEEE
Trans. Antennas Propagat., in press.
4. McFarland, R. L., “A family of difference sets in non-cyclic groups,” Journal of Combinatorial
Theory, Series A, Vol. 15, No. 1, 1–10, Jul. 1973.
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Interleaved Array Antennas Design — (Almost) Deterministic
Strategies
Massimiliano Simeoni1 , Ioan E. Lager1 , Cristian I. Coman2 , and Christian Trampuz1
1
International Research Centre for Telecommunications and Radar (IRCTR)
Faculty of Electrical Engineering, Mathematics and Computer Science
Delft University of Technology, CD Delft, The Netherlands
2
NATO Consultation, Command and Control Agency (NC3A), 2597 AK the Hague, The Netherlands
Abstract— The concept of interleaving sparse (sub)arrays for optimizing the aperture efficiency
of an antenna system, advocated in [1], and based on the principle of accommodating various types
of radiators on a common aperture, was detailed and discussed in [2]. The approach was referred
to as the ‘shared aperture concept’. The initial expectations were focused on reusing the empty
space available in non-periodic arrays for deploying individual elements or sub-arrays supporting
alternative services. Successively, array interleaving became a topic of investigation in itself,
demonstrating the versatility of this technique with clear ramifications in implementing multifunctionality. Shared aperture array antennas were designed to operate concurrently on multiple
bands [2], multiple polarizations [3] and to implement the different functions (i.e., transmitting
and receiving) of a continuous-wave (CW) radar system [4].
Naturally, a number of issues need to be addressed in designing a shared aperture antenna. Firstly,
the constituent sub-arrays need to be designed to satisfy their relevant requirements. Secondly,
a strategy for collocating them on the common aperture needs being identified. At this stage, it
is crucial avoiding any physical overlapping between the elements of the individual sub-arrays.
Finally, optimal use of the available aperture surface has to be ensured. The statistical properties
of the so-called Cyclic Difference Sets (CDSs), sets of numbers previously used in the realm of
communication technology and cryptography, can be exploited to design naturally interleaved
sub-arrays with well controlled radiation properties. The CDS-based technique is completely
deterministic, enabling a fast design yielding well predictable radiation performance [2, 3]. The
CDS-based technique, complemented by a trimming of the array elements, was adopted in [5] for
reducing the side-lobe radiation of a CW radar antenna system. Another way of addressing the
issues related to the design of a shared aperture antenna is resorting to statistical methods, an
example of this approach being reported in [6].
The present contribution will briefly recall the benefits brought by the shared aperture concept in
terms of implementing concurrent functionalities in the same array aperture. However, the focus
will be on the synthesis strategies to be used for designing shared aperture antennas; ranging
from the fully deterministic approaches to semi-deterministic ones up to purely statistical design
techniques. The pros and cons of each technique will be discussed and compared. Finally, some
practical implementations of the shared aperture concept will exemplify the advocated design
techniques.
REFERENCES
1. Haupt, R. L., “Interleaved thinned linear arrays,” IEEE Transactions on Antennas and Propagation, Vol. 53, No. 9, 2858–2864, Sep. 2005.
2. Coman, C. I., “Shared aperture array antennas composed of differently sized elements arranged
in sparse sub-arrays,” Ph.D. Dissertation, Delft University of Technology, Jan. 2006.
3. Simeoni, M., I. E. Lager, C. I. Coman, and A. G. Roederer, “Implementation of polarization
agility in planar phased-array antennas by means of interleaved subarrays,” Radio Science,
Vol. 44, RS5013, Oct. 2009.
4. Trampuz, C., M. Simeoni, I. E. Lager, and L. P. Ligthart, “Complementarity based design
of antenna systems for FMCW radar,” Proc. 5th European Radar Conference — EuRAD,
216–219, Amsterdam, The Netherlands, Oct. 2008.
5. Lager, I. E., C. Trampuz, M. Simeoni, and L. P. Ligthart, “Interleaved array antennas for
FMCW radar applications,” IEEE Trans. Antennas Propagat., Vol. 57, No. 8, 2486–2490,
Aug. 2009.
6. Trampuz, C., M. Simeoni, I. E. Lager, and L. P. Ligthart, “Low sidelobe interleaved transmitreceive antennas for FMCW radar applications,” IEEE Antennas Propagat. Symp. Dig.,
Charleston, USA, Jun. 2009.
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Antenna Array Synthesis through Time Modulation
L. Poli, P. Rocca, G. Oliveri, L. Lizzi, and A. Massa
ELEDIA Research Group at DISI, University of Trento, Via Sommarive 14, I-38123 Trento, Italy
Abstract— In the last years, there has been a renewed interest towards the use of timemodulated arrays (TMAs) thanks to the simplicity in reconfiguring the average pattern of the
antenna just modifying the on-off sequence controlling a set of radio-frequency (RF) switches.
TMAs have been originally introduced for the generation of low and ultra-low sidelobe patterns
for radar arrays [1] thus avoiding the implementation of impracticable excitation tapering with
high dynamic range ratios. However, they haven’t received a large diffusion because of the power
losses due to the generation of harmonic radiation at multiples of the time-modulation frequency.
As a matter of fact, the periodic modulation of the static excitations causes a shift of the radiated
power in the sideband radiation (SR) [2] with a consequent reduction of the directivity of the
pattern at the carrier frequency.
Recently, thanks to the significant development of stochastic optimization algorithms boosted
by the growing computational resources available with modern personal computers, several approaches have been proposed to deal with the synthesis of time-modulated arrays while keeping
low the power losses in the SR. Both single-agent techniques (e.g., Simulated Annealing [3]) and
evolutionary-based optimization methods (e.g., Differential Evolution [4] and Particle Swarm
Optimization [5]) have been effectively applied. In such a framework, TMAs have been used for
the generation of shaped beams as well as of sum and difference patterns for search-and-track
antenna systems [6]. Moreover, they have demonstrated being suitable for the synthesis of pulse
Doppler radars [7] and phase switch screens [8].
This contribution is aimed at reviewing the last advances in the synthesis of TMAs also showing
that the introduction of additional degrees of freedom available in the time domain and suitable for
the definition of the pulse sequence enables the synthesis of TMAs with improved performance.
More specifically, besides the control of the durations of the time pulses controlling the RF
switches for the definition of a desired pattern at the carrier frequency, also the optimization of
the switch-on instants has been taken into account. Such a strategy allows to spread the energy
lost in the SR on the whole visible range thus lowering the interferences, to generate and shape
the harmonic patterns, and to avoid the instantaneous reduction of some pattern features [9].
REFERENCES
1. Kummer, W. H., A. T. Villeneuve, T. S. Fong, and F. G. Terrio, “Ultra-low sidelobes from
time-modulated arrays,” IEEE Trans. Antennas Propag., Vol. 11, No. 6, 633–639, Nov. 1963.
2. Brégains, J. C., J. Fondevila, G. Franceschetti, and F. Ares, “Signal radiation and power
losses of time-modulated arrays,” IEEE Trans. Antennas Propag., Vol. 56, No. 6, 1799–1804,
Jun. 2008.
3. Fondevila, J., J. C. Brégains, F. Ares, and E. Moreno, “Optimizing uniformly excited linear
arrays through time modulation,” IEEE Antennas Wireless Propag. Lett., Vol. 3, 298–301,
2004.
4. Yang, S., Y. B. Gan, and A. Qing, “Sideband suppression in time-modulated linear arrays by
the differential evolution algorithm,” IEEE Antennas Wireless Propag. Lett., Vol. 1, 173–175,
2002.
5. Poli, L., L. Manica, P. Rocca, and A. Massa, “Handling sideband radiations in time-modulated
arrays through particle swarm optimization,” IEEE Trans. Antennas Propag., in press.
6. Rocca, P., L. Manica, L. Poli, and A. Massa, “Synthesis of compromise sum-difference arrays
through time-modulation,” IET Radar, Sonar & Navigation, Vol. 3, No. 6, 630–637, Dec. 2009.
7. Li, G., S. Yang, and Z. Nie, “A study on the application of time modulated antenna arrays
to airborne pulsed doppler radar,” IEEE Trans. Antennas Propag., Vol. 57, No. 5, 1578–1582,
May 2009.
8. Tennant, A. and B. Chambers, “Time-switched array of phase-switched screens,” IEEE Trans.
Antennas Propag., Vol. 57, No. 3, 808–812, Mar. 2009.
9. Manica, L., P. Rocca, L. Poli, and A. Massa, “Almost time-independent performance in timemodulated linear arrays,” IEEE Antennas Wireless Propag. Lett., Vol. 8, 843–846, Aug. 2009.
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A Complete MIMO System Built on a Single RF Communication
Ends
Vlasis Barousis, Athanasios G. Kanatas, and George Efthymoglou
University of Piraeus, Greece
Abstract— It is well known that Multiple Input — Multiple Output (MIMO) architectures
improve significantly the performance of wireless communication systems. Depending on the
system design, the effect of multiple antennas might be twofold; in spatial multiplexing mode,
the objective is the data rate maximization, by exploiting appropriately the structure of the
channel matrix to obtain independent signaling paths that can be used to support independent
data streams. Alternatively, in diversity mode the multiple antennas are jointly used in order
to effectively mitigate the negative effects of fading, thus improving the overall system reliability. Although the promising performance of MIMO systems necessitates their implementation
to modern wireless communications, the corresponding hardware complexity hinders the wide
application of such systems.
Recently, remarkable research work is drawn in order to investigate alternative MIMO architectures with reduced hardware complexity, while maintaining the total performance in the same
levels as in conventional MIMO approach. The effort mainly is focused on the reduction of the
required radio-frequency (RF) chains, which in classical approach equal the number of antenna
elements utilized. Indeed, antenna selection, RF pre-processing, antenna subarray’ formation and
beamspace MIMO reflect significant research work towards this aim. In this paper, we propose a
new MIMO architecture built on Electronically Steerable Parasitic Antenna Radiators (ESPAR).
Such antennas consist of a single active element which is surrounded by several parasitic (or
passive) elements in linear or planar arrangement. Beamforming abilities are achieved by tuning
the varactors loaded directly to the parasitic elements. Since a single active element is present,
a single driving port is required, thus reducing dramatically the implementation cost. However,
well known MIMO transmission and reception techniques applied to antenna space cannot be
used.
Therefore, we consider the whole design and operation at beamspace (i.e., wavevector) domain. In
particular, we show a novel technique in which an appropriate radiation pattern is formed at each
time slot, depending on the transmit symbol vector. In other words, in the proposed technique
the information of the transmit symbol vector is encoded to the transmit radiation pattern. On
the other hand, at the receiver we exploit ESPAR antennas to sample the impinging field during
one symbol period with different orthogonal radiation patterns to detect and decode the received
symbols. Moreover, the resulting bit error rate performance is compared with corresponding
traditional MIMO systems to show that it is possible to maintain high performance levels using
significantly reduced hardware MIMO transceivers.
Progress In Electromagnetics Research Symposium Abstracts, Cambridge, USA, July 5–8, 2010
Critical Wavenumbers in the Classification of Fractal Radiation
Patterns
Giovanni F. Crosta
Inverse Problems & Mathematical Morphology Unit
Department of Environmental Sciences, University of Milan-Bicocca
1, piazza della Scienza, Milan, IT 20126, Italy
Abstract—
Motivation: Fractal models apply to radiation patterns from the so-called fractal antennas and
to the description of wave propagation through a complicated environment. In antenna design
the prototype antenna array factor has been provided by Weierstraß functions and their bandlimited approximations. In antenna characterization one may want to assign a given (synthesized
or measured) radiation pattern to a fractal class.
Fractal Pattern Synthesis: Array antenna factors are synthesized by means of Weierstraß
functions [1]. In one spatial dimension (x1 ) one has
f [x1 ] :=
∞
X
b(D−2)m cos[2πbm x1 ]
m=0
where 1 < D < 2, and b is the wavenumber such that b > 1. It can be shown that the box-counting
(B) fractal dimension (dimB ) of the graph of f [.] (graph[f ]) satisfies dimB [graph[f ]] = D. Twodimensional fractal radiation patterns can be synthesized by separation of variables.
Classification of Synthesized Fractal Patterns: The spectrum enhancement (ση) algorithm,
introduced a few years ago [2 and references quoted therein] operates on the Fourier transform
of a function of two variables. It evaluates derivatives of integer [3] or of fractional order [4],
followed by some non-linear operations. By applying ση to a synthesized fractal pattern one
obtains a vector of morphological descriptors, which are submitted to a trainable classifier. A
typical classification result is displayed by Figure 1 where the center panel shows the fractal
pattern class centroids on the plane of the first two principal components z1 and z2 . Each of the
five classes (labelled 1, 3, 5, 6, 9) is composed of patterns such that b = 14 and 16. Moreover, in
class 1, D = 1.1; in class 3, D = 1.3 (sample pattern on the right panel); in class 5, D = 1.5; in
class 6, D = 1.6 and in class 9, D = 1.9 (sample on the left panel).
Problem to be Addressed: There are critical values of the wavenumber [5] at which the numerical estimation of dimB [graph[f ]] is affected by relevant errors. The goal of this investigation
is to determine whether or not the same wavenumber values are critical for the ση algorithm as
well and, in case they are, provide an explanation.
Figure 1.
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REFERENCES
1. Werner, D. H. and P. L. Werner, Radio Science, Vol. 30, No. 1, 29–45, 1995.
2. Crosta, G. F., “Image analysis and classification by spectrum enhancement: new
developments,” Proceedings of the SPIE, Vol. 7532, 75320L01–75320L12, 2010, Doi:
10.1117/12.838694.
3. Crosta, G. F., “Feature extraction by differentiation of fractional order,” Progress In Electromagnetics Research Symposium Abstracts, 425, Electromagnetics Academy, Cambridge, MA,
2006.
4. Crosta, G. F., “Morphological characterization of two-dimensional random media and patterns
by fractional differentiation,” Progress In Electromagnetics Research Symposium Abstracts,
627, Electromagnetics Academy, Cambridge, MA, 2008.
5. Jaggard, D. and X. Sun, “Scattering from bandlimited fractal fibers,” IEEE Trans. Ant.
Propag., Vol. 37, 1591–1597, 1989.
Progress In Electromagnetics Research Symposium Abstracts, Cambridge, USA, July 5–8, 2010
Artificial Magneto-superstrates for Gain and Efficiency
Improvement of Microstrip Antenna Arrays
H. Attia, O. Siddiqui, and O. M. Ramahi
University of Waterloo, Canada
Abstract— This paper presents an engineered magneto-dielectric superstrates designed to enhance the gain and efficiency of a microstrip antenna array without any substantial increase in
the antenna profile. The broadside coupled split ring resonator (SRR) inclusions are used in the
design of the superstrate. Numerical full-wave simulations of a 4 × 1 linear microstrip antenna
array working at the resonance frequency of 2.18 GHz and covered by the superstrate show a
gain enhancement of about 3.0 dB and an efficiency improvement of 10%. The total height of the
proposed structure, is λ0 /7 where λ0 is the free-space operating wavelength.
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Analytical Model to Compute the Far-field Radiation of Patch
Antennas Arrays Loaded with Metamaterial-superstrates
H. Attia, O. Siddiqui, and O. M. Ramahi
University of Waterloo, Canada
Abstract— The reciprocity theorem and the transmission line analogy are used to compute
the far-field radiation of a linear microstrip antenna array covered with an engineered magnetic
superstrate to increase the antenna gain. The single radiating element will be replaced by two
magnetic line sources using the cavity model. The evaluation of the far-field is transformed into
the evaluation of the field at the two magnetic line sources locations by applying the reciprocity
theorem. The broadside coupled split ring resonator (SRR) inclusions acting as building blocks
for the artificial magnetic superstrate are characterized analytically to obtain the effective permeability and permittivity to be used in the analytical model of the whole radiating system.
Numerical full-wave simulations are provided to verify the analytical results for the far-field
radiation.
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Rectangular Ring Antenna for On-body Communication System
N. Zainudin and M. R. Kamarudin
Wireless Communication Centre (WCC), Faculty of Electrical Engineering
Universiti Teknologi Malaysia, Skudai Johor, Malaysia
Abstract— The demand of smaller and compact antennas in modern mobile and wireless
communication system has been increasing [1]. Because of low cost and process simplicity, printed
monopole antennas are popular candidates for these applications and applicable in body centric
communications [2].
A simple and compact microstrip-fed printed monopole antenna is proposed in this design. The
antenna is composed of a rectangular ring for operating frequency at 2.45 GHz. The fabricated
printed rectangular ring antenna is shown in Figure 1. The configuration has rectangular base
with rectangular slot cut inside the patch resulting the rectangular ring [3]. The dimension of
the patch is 12 mm × 26 mm with ring width size of 1 mm along the patch. The size of partial
ground plane is 20 mm × 9 mm while the dimension of substrate used is 20 mm × 40 mm. The
antenna are designed on FR4 substrate with thickness of 1.6 mm, dielectric permittivity, εr is 4.7
and tangent loss is 0.019.
The designed antenna had been successfully simulated using CST Microwave Studio Suite. It
was found that the antenna operate well at 2.45 GHz. Return Loss measurement had been done
using spectrum analyzer and the simulated and measured results are in good agreement. The
antenna covers bandwidth from 2.35 GHz to 2.8 GHz which is 17.54%.
Figure 1: Antenna prototype front view and back view.
REFERENCES
1. Hall, P. S. and Y. Hao, (eds.), Antennas and Propogation for Body Centric Wireless Communications, Artech House, Boston/London, 2006.
2. Kamarudin, M. R., Y. I. Nechayev, and P. S. Hall, “Antennas for on-body communication
systems,” IEEE International Workshop on Antenna Technology: Small Antennas and Novel
Metamaterials, IWAT 2005, 17–20, March 7–9, 2005.
3. Deng, H., X. He, B. Yao, and Y. Zhou, “A compact square-ring printed monopole ultra wideband antenna,” Microwave and Millimeter Wave Technology, ICMMT 2008, 1644–1646, April
21–24, 2008.
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A New Fractal Antenna for Super Wideband Applications
Abolfazl Azari
Young Researchers Club, Isalmic Azad University, Gonabad Branch, Iran
Abstract— Modern communication systems require small size and wideband antennas. Fractal
geometries have been used to fabricate multi-band and broad-band antennas. In addition, fractal
geometries can be miniaturized the size of antennas.
In this work, I have investigated a new fractal antenna with multi-band and broad-band properties. The proposed design is a loaded the 2nd iteration of a new fractal geometry to a square loop
antenna. The simulation is performed via SuperNEC electromagnetic simulator software. The
simulation results show that the proposed antenna is applicable in 1–30 GHz frequency range.
Radiation patterns are also studied.
Progress In Electromagnetics Research Symposium Abstracts, Cambridge, USA, July 5–8, 2010
Koch Fractal Antenna for UWB Applications
Javad Rohani1 and Abolfazl Azari2
1
2
Islamic Azad University, Gonabad Branch, Iran
Young Researchers Club, Islamic Azad University, Gonabad Branch, Iran
Abstract— Fractals have very unique properties, Therefore in recent years, antenna designers
use fractal geometry in ultra wideband antennas designing.
In this paper, we have achieved an ultra wideband antenna by applying a Koch fractal geometry
to a wire square loop antenna. Modelling and simulation is performed via SuperNEC electromagnetic simulator. Also, optimization is performed via GAO (genetic algorithm optimiser). This
antenna is easy to be fabricated and has successfully demonstrated multi-band and broad-band
characteristics. Results of simulations show that the proposed antenna has very good performance
in bandwidth and Radiation pattern.
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