Fractal Patch Antenna Research Articles

Tri-Band Fractal Patch Antenna for GSM and Satellite Communication Systems

Due to their smaller size and light weighted structures patch antennas are accustomed in modern communication Technology. With additional size in reduction, micro strip antennas are commonly used in handsets, GPS receivers etc. This paper presents a novel design of fractal shape patch antenna using U-slot on patch and defected ground structure. Due to slots on patch and ground, tri-band resonating response is attained with maximum gain and directivity of 4.22dB and 6.51dBi showing high impedance bandwidth and radiation efficiency. The antenna showed good VSWR of 1.63 to 1.02 thus, showing high efficiency. As evident in the simulation results, the proposed antenna has been found useful for W-LAN, GSM, Radio Satellite, Fixed Satellite Services (RSS) & (FSS) and satellite communication systems.

A stacked sierpinski gasket fractal antenna with a defected ground structure for UWB/WLAN/RADIO astronomy/STM Link applications

ABSTRACTAn aperture coupled stacked Sierpinski gasket fractal antenna with a defected ground structure is proposed in the current article for ultra wide band (UWB) and wireless local area network (WLAN) applications. The radiating structure is formed of two Sierpinski gasket fractal patch antenna layers on two layers of FR4 substrate stacked one over the other. This stacked structure is fed by a third (bottom) layer also of FR4 substrate, with ground layer at its top and the feed line with a stub, at the bottom. The top ground layer has a ‘†’ shaped slot cut in it to provide a wideband behavior to the antenna, and the feed line is designed with a stub to provide circular polarization to the EM fields radiated by the proposed antenna. The antenna is designed using CST Microwave Studio version 2010 assuming perfect boundary conditions. The proposed antenna shows a dual band wideband behavior with an impedance bandwidth of 630 MHz (4.75–5.38 GHz) and 400 MHz (6.8–7.2 GHz) with a gain of 5.85 dB and 9.5 dB at the center frequencies of the two bands, respectively. The antenna is capable of covering two UWB bands from (4.75–5.28) GHz and (6.8–7.2) GHz, a radio astronomy band from (5.01–5.03) GHz and IEEE 802.11a band from (5.15–5.35) GHz. The prototype of the proposed antenna is tested using a VNA and an anechoic chamber to validate against the simulated results. The proposed antenna has volumetric dimensions of 6 × 6 × 0.483 cm3 which makes it a suitable choice for RF front end circuits. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2786–2792, 2015

DESIGN OF T-SHAPED FRACTAL PATCH ANTENNA FOR WIRELESS APPLICATIONS

Since the evolution of the patch antennas, there is rapid growth observed in the applications of the patch antenna. There are number of advantages such as small size, ease of fabrication and installment, and a stable performance, so there are huge number of designs has been developed and presented by the researchers time to time. Taking an example of the mobile phone antennas, the antenna must have a small size and must be capable to resonate at multiple frequency bands. Reviewing about the various requirements of the antenna design for the wireless applications a novel multiple band fractal patch antenna has been designed. In this paper, a T-shaped patch antenna has been designed and discussed and fractal geometry has been applied to it in order to obtain self-similar characteristics. The dimensions of the Square Patch has been taken as 36 x 36 mm. Dimension of ground has been taken as been taken as 50 x 50 mm. The substrate material used for antenna design is FR-4 having dielectric constant 4.4. Antenna resonates at four operating bands 3.5 GHz, 4.48 GHz, 6.1 GHz and 8.17 GHz. This antenna has return loss of -16.76 dB, -16 dB, -28.63 dB and -15.03dB with bandwidth of 432 MHz, 332 MHz, 295 MHz and 364 MHz at resonant frequencies. Further this antenna has impressive gain of 3.55 dBi, 5.7 dBi and 3.16 dBi and 3.27 dBi at corresponding frequencies. This antenna can be useful for Wi-Max, 4G network, WLAN, Satellite & RADAR communication applications.

A CSRR-Fed SIW Cavity-Backed Fractal Patch Antenna for Wireless Energy Harvesting and Communication.

This paper presents a novel compact dual-band and dual-polarized complementary split-ring resonator (CSRR)-fed substrate-integrated waveguide (SIW) cavity-backed fractal patch antenna for wireless energy harvesting and communication. The proposed antenna is composed of a Giuseppe Peano fractal radiation patch with a backed SIW cavity. To enhance the bandwidth and minimize the dimensions, the CSRR structure is designed to feed the Giuseppe Peano fractal patch orthogonally. A prototype of the proposed antenna is simulated, fabricated and measured. The proposed antenna exhibits good directionality and high cross-polarization level with especially compact size.

Design Tri-Band Fractal Antenna with Minkowski Island Split Ring Resonator Structures

The paper investigates the effect of Minkowski Island split ring resonator (MI-SRR) on the microstrip fractal patch antenna. Firstly, a basic Minkowski Island had been simulated in the CST Microwave Studio. Then, the addition of several sizes of the Minkowski Island split ring resonator on the substrate had been generated tri-band resonant frequencies. The optimal result of this tri-band antenna 2.394 GHz, 3.528 GHz and 5.257 GHz with a gain of 0.874 dB, 1.41 dB and 2.94 dB and the reflection coefficient magnitudes of - 21.945 dB, - 17.154 dB and – 16.536 dB. The reflection coefficient magnitudes of the simulation and fabricated antenna also had been compared. The target application for this antenna is for WLAN and WiMAX.

Miniaturized stacked implant antenna design at ISM band with biocompatible characteristics

Purpose – A vertically stacked, three layer hybrid Hilbert fractal geometry and serpentine radiator-based patch antenna is proposed and characterized for medical implant applications at the Industrial, Scientific and Medical band (2.4-2.48 GHz). Antenna parameters are optimised to achieve miniaturized, biocompatible and stable transmission characteristics. The paper aims to discuss these issues. Design/methodology/approach – Human tissue effects on the antenna electrical characteristics were simulated with a three-layer (skin, fat and muscle) human tissue model with the dimensions of 180×70×60 mm3 (width×height×thickness mm3). Different stacked substrates are utilized for the satisfactory characteristics. Two identical radiating patches are printed on Roger 3,010 (ε r=10.2) and Alumina (ε r=9.4) substrate materials, respectively. In addition, various superstrate materials are considered and simulated to prevent short circuit the antenna while having a direct contact with the metallization, and achieve biocompatibility. Finally, superstrate material of Zirconia (ε r=29) is used to achieve biocompatibility and long-life. A finite element method is used to simulate the proposed hybrid model with commercially available Ansoft HFSS software. Findings – The antenna is miniaturized, having dimensions of 10×8.4×2 mm3 (width×height×thickness mm3). The resonance frequency of the antenna is 2.4 GHz with a bandwidth of 100 MHz at return loss (S11) of better than −10 dB characteristics. Overall, the proposed antenna have 50 Ω impedance matching, −21 dB far field antenna gain, single-plane omni-directional radiation pattern properties and incident power of 5.3 mW to adhere Specific Absorption Rate regulation limit. Originality/value – Vertically stacked three layer hybrid design have miniaturized characteristics, wide bandwidth, biocompatible, and stable characteristics in three layer human tissue model make this antenna suitable for implant biomedical monitor systems. The advanced simulation analysis of the proposed design constitutes the main contribution of the paper.

Dual Band and Beam-Steering Antennas Using Reconfigurable Feed on Sierpinski Structure

Fractal patch antennas based on the Sierpinski structure are studied in this paper. The antennas operate at dual bands (around 2 and 5 GHz) and are designed to steer the beam directions at around 5 GHz band (the first harmonic). The antennas use reconfigurable triple feeds on the same antenna plane to have three beam directions. The same scale factor defines the geometrical self-similarity of the Sierpinski fractal. The proposed antennas are fabricated through three iterations from 1st order to 3rd order and utilize FR-4 (εr= 4.4) for the microwave substrate. The performances of the antennas, such as reflection coefficients and radiation patterns are verified by simulation and measurement. The results show that the properties of the proposed antennas in three orders are similar.

English

Microstrip antennas find applications in aircraft, satellite and missile applications where important characteristics are size, weight and complexity. Design and simulation has been carried out using IE3D simulation software. Minkowski fractal geometry has been applied on patch of antenna to form self similar H-shaped patch antenna. By applying DGS in horizontal direction and vertical direction, characteristics of antenna are observed. When DGS has been changed in horizontal direction and Fr-4 has been used as substrate then antenna resonated at 2.7 GHz, 4.8 GHz and 6.2 GHz with return loss of -17.66 dB, -13.6 dB and -23.66 dB. This antenna has gain of 6.05 dBi, 5.6 dBi and 3.66 dBi. Results are also obtained for H-shaped fractal patch antenna by applying plus shaped DGS and slot shaped DGS, hence antenna can be used for WLAN applications. When microstrip feed line has been used, proposed antenna can be useful for GPS application

A cross‐stitch geometry‐based multiband fractal antenna

AbstractFractal antennas have the characteristics of radiating in the multiple frequency bands due to self‐similarity property. Using the same, a new fractal patch antenna is presented in this article. The antenna is based on cross‐stitch geometry. The simulation and measured results show that the proposed antenna has multiband performance with sufficient gain and high directivity. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:667–671, 2014

A Modified Crown Square Fractal Patch Antenna for Dual and Multiband Operation

A simple and efficient method of achieving multiband operation on a microstrip patch antenna is presented on this paper. The patch is designed by simply modifying the crown square geometry, which is fractal geometry. Multiband characteristic is obtained by the self similar property of the designed patch. Method to vary the operational frequencies for one antenna is also suggested. The physical dimensional parameters of the designed antenna can be adjusted so as to obtain the frequencies to some useful frequency ranges. The proposed antennas are giving broadside radiation on the working frequencies. The antennas are designed using finite element method based HFSS and its performance is demonstrated in terms of return loss, radiation pattern and VSWR.

Modeling and Simulation of Sierpinski Pentagon Fractal Antennas

Measurements of fractal shaped antennas are not enough to understand their physical behavior and there are antenna characteristics that can not be obtained by present day measurement techniques. Therefore, in the present work, the Ansoft HFSS finite element electromagnetic computer package was used to model, simulate and analyze the Sierpinski pentagon monopole microstrip patch fractal antenna and its complementary. The simulation results for both antennas show good matching with their feeds in the frequency range (2 GHz–12 GHz) and indicate that they can operate in the UMTS (2000 MHz–2200 MHz), Bluetooth (2400 MHz–2480 MHz), WLAN (2.4 GHz) and HIPERLAN (5.2 GHz) bands. Also, the computed results show, in general, good agreement with measured data for the S-parameter and radiation patterns.

Study of Effect of Variations in slot dimensions on Fractal Patch antenna Performance

An antenna is a device that is made to efficiently radiate and receive radiated Electromagnetic waves. Microstrip antennas are attractive due to their light weight, conformability and low cost. These antennas can be integrated with printed strip-line feed networks and active devices. This is a relatively new area of antenna engineering. For reducing the size of antenna, fractal geometries have been introduced in the design of patch antenna. Fractal antennas also called as space filling curves are very compact, multiband or wideband, and have useful applications in cellular telephone and microwave communications. In our research work, we have used IE3D software for designing the antenna. We study the effect of variations of slot dimensions on antenna performance so as to obtain good results. In this research work, four different fractal patch antennas are designed. The rectangular base geometry is same for the all four antennas but the elliptical slot dimensions differ. In simulation, S parameters of all four antennas are analyzed. From the S parameter displays, comparison of all four antennas is done on the basis of three parameters that are: Lowest frequency, Multiband and S11 values. The simulation results shows that as the elliptical slot dimension decreases on rectangular patch antenna, the performance of fractal patch antenna improves on the basis of three factors that are lowest frequency, multiband and s11 values.

STUDY AND COMPARATIVE ANALYSIS OF RESONAT FREQUENCY FOR MICROSRTIP FRACTAL ANTENNA

A new compact fractal patch antenna is designed based on the fractal geometry. Based on the simulation results, the proposed antenna has shown an excellent size reduction possibility with good radiation performance for wireless communication applications. The change in resonating frequency with respect to the dielectric constant of substrate has shown and discussed in this paper. The various resonating frequencies for designed antenna are 8.59GHz, 9.2 GHz and 11.36 GHz for RT Duroid Rogers 6010, FR 4 and RT Duroid Rogers 5880 respectively. The S-parameter (S11) for resonating frequencies is well below -10 dB. The far-field patternandS11oftheproposedantennaissimulatedandanalyzedusingCST Microwave Studio 2011 Index Terms: Microstrip antenna, Fractal antenna, Multiband antenna, and Plusses geometry

Particle Swarm Optimization for Multiband Metamaterial Fractal Antenna

The property of self-similarity, recursive irregularity, and space filling capability of fractal antennas makes it useful for various applications in wireless communication, including multiband miniaturized antenna designs. In this paper, an effort has been made to use the metamaterial structures in conjunction with the fractal patch antenna, which resonates at six different frequencies covering both C and X band. Two different types of square SRR are loaded on the fractal antenna for this purpose. Particle swarm optimization (PSO) is used for optimization of these metamaterial structures. The optimized metamaterial structures, after loading upon, show significant increase in performance parameters such as bandwidth, gain, and directivity.

UWB CPW-Fed Fractal Patch Antenna With Band-Notched Function Employing Folded T-Shaped Element

A compact coplanar waveguide (CPW) monopole antenna is presented, comprising a fractal radiating patch in which a folded T-shaped element (FTSE) is embedded. The impedance match of the antenna is determined by the number of fractal unit cells, and the FTSE provides the necessary band-notch functionality. The filtering property can be tuned finely by controlling of length of FTSE. Inclusion of a pair of rectangular notches in the ground plane is shown to extend the antenna's impedance bandwidth for ultrawideband (UWB) performance. The antenna's parameters were investigated to fully understand their affect on the antenna. Salient parameters obtained from this analysis enabled the optimization of the antenna's overall characteristics. Experimental and simulation results demonstrate that the antenna exhibits the desired VSWR level and radiation patterns across the entire UWB frequency range. The measured results showed the antenna operates over a frequency band between 2.94–11.17 GHz with fractional bandwidth of 117% for <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm VSWR} \leq 2$</tex></formula> , except at the notch band between 3.3–4.2 GHz. The antenna has dimensions of 14 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\,\times\,$</tex> </formula> 18 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\,\times \,$</tex> </formula> 1 mm <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$^{3}$</tex> </formula> .

Dielectric Loading on Multi-Band Behaviors of Pentagonal Fractal Patch Antennas

This paper describes the multiband behaviour as well as the response for dielectric loading of a pentagonal fractal patch antenna designed at frequency f = 2.45 GHz. The proposed antenna shape has been obtained by introducing slots in a pentagonal patch antenna up to second iteration. Detailed design steps and results of the designs are studied and investigated in this paper. Simulated and measured results reveal that the antenna will be operated at three different frequency bands—2.17 GHz, 3.56 GHz, and 7.93 GHz with acceptable performances (i.e. VSWR < 2). The measured results for the antennas are in good agreement with simulated results. The proposed antenna maintains good radiation pattern with gain. However dielectric loading increases its radiation efficiency at the cost of significant decrease in gain and directivity.

A Novel Method to Improve Current Density in Multiband Triangular Fractal Antenna

In this paper modified feed for Sierpensiki gasket Fractal shaped is presented. Sierpensiki gasket structure is most widely used method in microstrip patch antenna design for multiband operation. But Sierpensiki gasket antenna suffers from the problem of reach of current density over complete fractal patch. In this paper a modified feeding structure is proposed for triangular shaped Sierpensiki gasket fractal patch antenna to have uniform current density throughout the fractal patch. The improvement is studied in terms of return loss and efficiency of antenna. Proposed feeding technique improves power flow throughout antenna so that it reaches small fractal as well as larger fractal structures. The simulated result shows agreement with the theoretical results. DOI: http://dx.doi.org/10.5755/j01.eee.18.10.3058

Parametric Study of UC-PBG Structure in Terms of Simultaneous AMC and EBG Properties and its Applications in Proximity-coupled Fractal Patch Antenna

In this paper, a parametric study of conventional Uniplanar Compact Photonic Band Gap (UC-PBG) structures, with different dimensions, is investigated. The studied structure operates as an Artificial Magnetic Conductor (AMC) in which the performance is mainly characterized by the resonant frequency and bandwidth. Simulation and numerical analysis have been carried out using CST Microwave Studio software, which is based on Finite Difference Time Domain (FDTD), and Ansoft HFSS which is based on Finite Element Method (FEM). Results show that different dimensions affect the AMC\'s performance. The increase in the length and width of the UC-PBG slot will result in lower resonant frequencies and bandwidth degradation, while the frequency band position and the bandwidth will increase when the branch width have been increased. Furthermore, a prototype of a microstrip line proximity-fed to a fractal patch antenna on a UC-PBG substrate is designed and simulated. Computed results show that the antenna mounted on the UC-PBG substrate has over 9.2% wider impedance bandwidth than the same antenna etched on a grounded dielectric slab with same the same characteristics, due to in-phase reflection phase of UC-PBG structure. Compared with the reference antenna at 7.2 GHz, the back lobe is reduced by 7.86 dB in E plane and 7.68 dB in H plane. Cross-polarization level remains below -10 dB in both E and H planes.

INVESTIGATION ON MICROSTRIP PATCH FRACTAL ANTENNA

Abstract A new design of Microsrtip patch fractal antenna for 2.5 GHz is proposed which possess an excellent size reduction possibility with good radiation performance for wireless applications like Wireless Local Area Network (WLAN). The design and simulation results of microstrip patch fractal antenna using Ansoft HFSS is presented which has S11 < -10 dB (VSWR<2). The antenna is designed based on the transmission line model with the input impedance of 50 ohm. The fractal geometry for the conventional antenna is generated up to second iteration. The results show that size reduction of 51.9% can be achieved as compared to conventional patch antenna.

Modal Resonant Frequencies and Radiation Quality Factors of Microstrip Antennas

The chosen rectangular and fractal microstrip patch antennas above an infinite ground plane are analyzed by the theory of characteristic modes. The resonant frequencies and radiationQare evaluated. A novel method by Vandenbosch for rigorous evaluation of the radiationQis employed for modal currents on a Rao-Wilton-Glisson (RWG) mesh. It is found that the resonant frequency of a rectangular patch antenna with a dominant mode presents quite complicated behaviour including having a minimum at a specific height. Similarly, as predicted from the simple wire model, the radiationQexhibits a minimum too. It is observed that the presence of out-of-phase currents flowing along the patch antenna leads to a significant increase of theQfactor.