Sierpinski Gasket Fractal Antenna Research Articles

Design of a Compact Reconfigurable Sierpinski Gasket Fractal Antenna for 5G and Satellite Communications

Reconfigurability is one of the key features of 5G/6G radiofrequency systems. The possibility to adapt the working frequency depending on the application or the status of the nodes is important, especially in Smart Radio Environments. In this regard, the design of antennas operating at different frequency bands is challenging since strict requirements on the footprints and the radiation properties are introduced. Among other geometries, fractals present unique features in terms of small electrical lengths: they have been used for years by researchers to shrink antenna dimensions in a very effective way. An interesting perspective of these antennas is the possibility to switch the working frequency among several bands connecting/disconnecting the fractal cells. The aim of this paper is the design and the optimization of an electrically reconfigurable Sierpinski gasket fractal antenna. Four different states are obtained: in the first the device works at 27 GHz (mmWave), in the second at 16 GHz, in the third at 11 GHz (Ku-band), and in the fourth at 3.5 GHz (Sub-6GHz). The antenna operates efficiently in all the bands of interest.

A complementary Sierpinski gasket fractal antenna array integrated with a complementary Archimedean defected ground structure for portable 4G/5G UWB MIMO communication devices

AbstractThis article presents the design, development, and experimental validation of an aperture coupled complementary Sierpinski gasket equilateral triangular fractal antenna array for portable 4G/5G UWB communication devices. The proposed antenna array is printed on two FR‐4 substrate layers (ε r = 4.4, height = 1.57 mm, and tan δ = 0.024) with two fractal triangular patches on the top layer (separated by a distance of 3λ/2) and feed network on the bottom layer of FR‐4. The fractal patches (optimized up to second order of iteration) are fed using an aperture‐coupled feeding mechanism, where the aperture slots in the ground layer are modified to complementary Archimedean spiral slots which are interconnected by a modified “X” shaped slot to improve the impedance matching at the operational bands. The proposed array has overall volumetric dimensions of 41 × 99.4 × 3.245 mm3 and provides a size reduction of 46% for the metallic area using the fractal geometry. The proposed array shows a simulated UWB response from 4.3 to 11.6 GHz (fractional bandwidth of 91.8% at 7.95 GHz) with a simulated peak gain of 4.7 dB (at 9.2 GHz) and port‐to‐port isolation of ≤−15.8 dB for the entire band. For validation of simulated responses, the proposed array is fabricated and tested for S‐parameters (S11, S22, S12, and S21). A measured impedance bandwidth of 6.3 GHz is observed for a frequency band from 5.7 to 12 GHz. Two additional frequency bands are also exhibited by the array from 4.1 to 4.25 GHz and 4.7 to 5.3 GHz. The array diversity parameters such as envelope correlation coefficient (≤0.007 [simulated], ≤0.0057 [measured]), diversity gain (≥9.999 [simulated], ≥9.971 [measured]), mean effective gain (≥−3.9 dB [simulated], ≥−5.1 dB [measured]), and channel capacity loss, (≤0.37 bits/s/Hz [simulated], ≤0.4 bits/s/Hz [measured]) which are calculated using the simulated and measured S‐parameters of the array are also observed. These parameters allow the proposed fractal array to be implemented in a diversity combining technique to improve the overall SNR and hence support a high data rate for 4G/5G multimedia services.

Design of micro‐machined modified Sierpinski gasket fractal antenna for satellite communications

Modified Sierpinski gasket fractal patch antenna for earth exploration satellite services has been proposed in this article. The proposed antenna is designed up to third iterative fractal geometry on the FR4 substrate having dielectric constant of 4.4 with height of 0.8 mm. The proposed design shows multiband characteristics at 2.8, 6.1, 7.96, 16, and 17 GHz frequencies. The maximum gain of the proposed design is 9.6 dBi has been achieved in Ku-band. The resonating performance characteristics and radiation characteristics of the final iteration are investigated using simulator and experimentally to verify the results of the proposed design. The simulated and measured performance parameters show quite resemblance. Further, proposed design has been simulated on the micro-machined high resistive silicon substrate which causes the improvement in gain and efficiency. Micro-machined fractal antenna is compatible with monolithic microwave integrated circuits (MMICs).

A complementary Sierpinski gasket fractal antenna array for wireless MIMO portable devices

AbstractThis research work reports the design and development of a novel complementary Sierpinski gasket fractal microstrip antenna array to achieve a good impedance bandwidth and hence support high data rates for 4G/5G MIMO applications. The proposed array is a compact structure (136 mm × 136 mm) designed with complimentary Sierpinski gasket fractal up to two iterations and has a defected ground to improve the antenna's performance. The antenna performance reports an 8.2% bandwidth at the center frequency of 4.94 GHz (4.7434‐5.1514 GHz), a simulated diversity gain of 9.99 allows the proposed array to be well suitable for proposed applications and a directivity of around 5.8 dBi suits good range characteristics. The array designing and optimization is carried out with 3D EM tool CST MWS V'14 using perfect boundary approximations. A simulated low value of envelope correlation coefficient (0.04) indicates that the two antennas in the array provide least interference to each other while radiating. The measured S11 results on a VNA E 5071C show a close match with the simulated results. Thus a compact array size with good bandwidth, radiation characteristics, low ECC and a high diversity gain allow the antenna array to be well suitable for portable MIMO 4G/5G wireless applications specifically for C band and military applications.

Analysis of Modified Square Sierpinski Gasket fractal microstrip antenna for Wireless communications

In this paper, the slot loaded microstrip antenna has been developed with Sierpinski gasket technique. The proposed Modified Square Sierpinski Gasket (MSSG) fractal antenna involves a square patch utilizing Sierpinski gasket (triangular) structure. Four triangular slots are loaded at each iteration. The structure is then simulated using commercially available Ansoft HFSS simulator. The multi-band operation has been achieved by the proposed antenna at 15.915 GHz, 20.045 GHz, 23.077 GHz, 27.77 GHz frequencies with −20 dB, −25 dB, −22 dB, −28 dB return loss respectively which works well for Ku (12–18 GHz) and K (18–27 GHz) band. The consistent result is obtained after simulation and the validity of fabricated design is checked by the measured result. The designed antenna is an attractive candidate for applications like wireless multi-band 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 SIERPINSKI GASKET FRACTAL ANTENNA WITH SLITS FOR MULTIBAND APPLICATION

There is highly demand of antenna with these characteristics: compact size, low profile and multiband or broadband but at the same time have to maintain antenna parameters. This paper focuses on design of Sierpinski Gasket Fractal Antenna (SGFA) with slits for multiband application.Two methods are applied to this antenna to improve its performance. The first method is by adding two slits on the fractal antenna. The second method is by increasing the number of iterations of the fractal antenna. These methods can improve the return loss and gain of the antenna. The simulation of the designed antenna is carried out by using Computer Simulation Technology (CST) software. The simulated return loss of SGFA with slit is about -20.1 dB and -11.64 dB compare with SGFA without slit -19.25 dB and -12.27 dB at 2.4 GHZ and 5 GHz. While, the gain also increase when slit is added to SGFA. The simulated and measured of antenna parameter is well compared

Design of Sierpinski Gasket Fractal Antenna using Proximity coupled feed mechanism for Multiband Applications

Design of Sierpinski Gasket Fractal Antenna using Proximity coupled feed mechanism for Multiband Applications

Performance comparison of bio-inspired optimization algorithms for Sierpinski gasket fractal antenna design

The Sierpinski gasket fractal antenna is most popular structure in the domain of fractal antennas. This fractal antenna has multi-band performance, and hence, the design of this antenna for the desired frequencies is a challenging problem. The artificial intelligence tools like artificial neural networks, fuzzy logic systems, bio-inspired optimization techniques are appropriate to provide accurate design solution in such cases. In this paper, three most popular bio-inspired optimization algorithms: genetic algorithms, particle swarm optimization (PSO), and bacterial foraging optimization, have been proposed to solve the design issues of Sierpinski gasket pre-fractal antenna. Their performances are analyzed and are compared with the experimental results. A simplified expression for calculation of resonant frequency of Sierpinski gasket pre-fractal antenna is proposed and is used as the objective function. Finally, the effectiveness is compared on the basis of three different measures: mean absolute percentage error, the average time taken by the models to evaluate the results, and the coefficient of correlation. The results indicate that the PSO algorithm is most suitable for this type of antenna.

Artificial Neural Network Analysis of Sierpinski Gasket Fractal Antenna: A Low Cost Alternative to Experimentation

Artificial neural networks due to their general-purpose nature are used to solve problems in diverse fields. Artificial neural networks (ANNs) are very useful for fractal antenna analysis as the development of mathematical models of such antennas is very difficult due to complex shapes and geometries. As such empirical approach doing experiments is costly and time consuming, in this paper, application of artificial neural networks analysis is presented taking the Sierpinski gasket fractal antenna as an example. The performance of three different types of networks is evaluated and the best network for this type of applications has been proposed. The comparison of ANN results with experimental results validates that this technique is an alternative to experimental analysis. This low cost method of antenna analysis will be very useful to understand various aspects of fractal antennas.

Modified Sierpinski Gasket Patch Antenna for UMTS and 2.4/5.2 WLAN

A modified Sierpinski Gasket fractal antenna for multiband application is proposed in this paper. The modified ground plane and the microstrip feed are used to obtain the wider bandwidth at the resonance frequency. The antenna is designed and printed on two layers FR-4 substrate (εr=4.4 and h=1.6 mm) to cover the UMTS and 2.4/5.2 WLAN. The radiation pattern of the proposed antenna is similar to an omnidirectional. The proposed antenna has maximum gain of 1.88, 1.6, 4.31 dB at 2, 2.4, 5.2 GHz, respectively The properties of the antenna such as return losses, radiation pattern, input resistance and gain are determined via numerical CST Microwave Studio 2010 software.

Sectoral sierpinski gasket fractal antenna for wireless LAN applications

A sectoral Sierpinski Gasket fractal (SSGF) antenna is proposed for dual-band operation with wide-bandwidth covering GPS, DCS-1800, PCS-1800, UMTS, IMT-2000, Wireless broadband Internet Services (WiBro), Bluetooth, and WLAN bands. The SSGF antenna consists of volume 65.5 × 27 × 1.6 mm3. To analyze its performance, measurements are carried out. The proposed antenna model exhibits resonances in 1.51–3.39 GHz (2:1 VSWR BW 76.6%) and 5.31–6.32 GHz (2:1 VSWR BW 17.3%) bands with 2.5–5 dBi gain. Very good agreement is obtained between simulation and experimental results. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012.

Design of Sierpinski gasket fractal microstrip antenna using real coded genetic algorithm

A novel technique for designing Sierpinski gasket fractal microstrip antenna is proposed. In the absence of any available closed-form formulae, this scheme uses an evolutionary method, based on real coded genetic algorithm (RCGA) in conjunction with electromagnetic simulations. This method determines the side-length and the fractal iteration number of the antenna, for operation at 4.56, 7.51 and 11.78 GHz. The design simulation of the antenna uses two different RCGA implementation strategies. The Adewuya mating with Gaussian mutation is the basis for the first one, whereas the second one uses heuristic crossover in conjunction with non-uniform mutation. Converging results, from these two strategies to those obtained from experiments on fabricated prototypes, validate the proposed method.

Radiation properties of modified fractal microstrip antennas

AbstractThis paper describes the method of configuration and the radiation properties of a new type of multi‐band planar antenna with a radiating element made of a microstrip antenna (MSA) with a slit‐loaded modified Sierpinski Gasket fractal antenna. In order to verify the multiband characteristics of this antenna, triangular MSA elements loaded with slits of a modified Sierpinski Gasket structure are fabricated. According to the experiment, the present test antenna exhibits excellent multiband characteristics in the C‐band and X‐band. Also, the measured values of the return loss and the radiation patterns are in good agreement with the results given by an electromagnetic simulator in the range meaningful for design. Thus, this antenna system is a useful format for a multiband planar antenna. © 2006 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 89(9): 10–21, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20296

Characterization of a Self-complementary Sierpinski Gasket Microstrip Antenna

Fractal antennae are recent topic of research interest. This work reports a self- complementary Sierpinski Gasket fractal microstrip patch antenna. The flrst iteration is named CSMASLI1, which stands for Complementary Sierpinski Microstrip Antenna Same Layer Iter- ation 1 and similarly the second iteration is named as CSMASLI2. The antennas are analyzed for two iterations using commercially available electromagnetic simulation software IE3D TM and CST Microwave Studio TM . The antenna radiates prominently at all resonant frequencies. The impedance bandwidth increases at higher harmonics. The radiation pattern is consistent for the difierent resonant frequencies and for difierent iterations. However some undulations are ob- served at higher resonance. Thus this new design can have usage in vehicle-mounted antenna for multiband wireless systems. A prototype was experimented which matches simulated results.

Multiband characteristics of two fractal antennas

Experimental results show a multiband behavior for the Sierpinski gasket fractal antenna and the tree-like fractal antenna. Such behavior has been explained by the fractal structures of the antennas. We show that the matched frequencies possess a log-periodic behavior. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 23: 242–245, 1999.

Multiband characteristics of two fractal antennas

Experimental results show a multiband behavior for the Sierpinski gasket fractal antenna and the tree-like fractal antenna. Such behavior has been explained by the fractal structures of the antennas. We show that the matched frequencies possess a log-periodic behavior. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 23: 242–245, 1999.