There are various patch antennas used for Wi-Fi and Wi-MAX applications. But, the problems with them
are low gain, low power handling capacity and hence, conventional yagi-uda antennas are used.
Conventional yagi-uda antennas are used in applications where high gain and directionality are
required. Generally, numbers of directors are added to increase gain of these antennas. But, here we
present modified yagi-uda antennas, in which the gain and bandwidth can be enhanced by not adding
additional directors.
In this paper, we initially discuss the designs of various yagi-uda antennas with uniform, non-uniform
spacings between directors and then we discuss their gain and bandwidth enhancement by various
approaches. Simulation results show that, the proposed techniques can enhance gain as well as
bandwidth when compared with the traditional yagi-uda antennas.
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is an open access international journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Compact Digital Television (DTV) Antenna for Indoor Usage IJECEIAES
A compact indoor digital antenna for digital terrestrial television is proposed. The design of the antenna begins with the material selection to construct the antenna by using CST software with a standard monopole antenna design. The antenna is then simulated and optimized. A bandwidth of 290 MHz (46.14%) between 500 MHz and 790 MHz is achieved with the antenna gain more than 3 dBi. Simulated results is used to demonstrate the performance of the antenna. The simulated return losses, together with the radiation patterns and gain are presented and discussed.
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is an open access international journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Compact Digital Television (DTV) Antenna for Indoor Usage IJECEIAES
A compact indoor digital antenna for digital terrestrial television is proposed. The design of the antenna begins with the material selection to construct the antenna by using CST software with a standard monopole antenna design. The antenna is then simulated and optimized. A bandwidth of 290 MHz (46.14%) between 500 MHz and 790 MHz is achieved with the antenna gain more than 3 dBi. Simulated results is used to demonstrate the performance of the antenna. The simulated return losses, together with the radiation patterns and gain are presented and discussed.
Cube satellite missions perform innovative scientific experiments on a low cost developmental platform but
have an inherent limitation of size and space. This restricts the total available solar power that can be
harnessed and as a result, the radio links operate on stringent power budgets. For improving the available
margins for communication in such satellites, it is desirable to improve upon the antenna system
performance at the ground station used for the establishment of the links with the satellite. This can be
achieved by improving the forward gain, the forward to backward ratio and the directivity of the antenna.
This paper describes the electrical simulations and the performance evaluation of the one unit, two unit and
four unit circularly polarized crossed Yagi-Uda antenna array designed for communication with amateur
radio (HAM) satellites operating over the 434 MHz to 438 MHz Amateur UHF band. The electro-magnetic
model has been developed using the 4NEC2 software. The simulations have been validated with the
practical field testing performed for estimating the SWR, antenna gain, the forward to backward ratio and
radiation pattern for the antenna system.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
ER Publication,
IJETR, IJMCTR,
Journals,
International Journals,
High Impact Journals,
Monthly Journal,
Good quality Journals,
Research,
Research Papers,
Research Article,
Free Journals, Open access Journals,
erpublication.org,
Engineering Journal,
Science Journals,
Design and Simulation of Compact Wideband Rectangular Dielectric Resonator An...ijsrd.com
An objective of the paper is to optimize the parameters, and simulation analysis of compact wideband rectangular dielectric resonator antenna (RDRA). In this paper, a compact wideband, rectangular dielectric resonator antenna is presented using relatively low dielectric constant material and using double microstrip patch. The rectangular DRA is fed with a modified stepped microstrip feed to ensure efficient coupling between the RDRA and the feeder. The performance of the proposed antenna has been significantly improved by loading the RDRA with two narrow conducting metallic strips of suitable widths, which results in dual-resonance excitation and leads to a wider operating bandwidth (16.274-18.200 GHz). The frequency characteristics and radiation performance of the proposed antenna are successfully optimized. Design and simulation results are in excellent agreement.
Design of Reconfigurable Microstrip Patch Antenna for WLAN ApplicationEditor IJMTER
In this paper we propose a rectangular microstrip patch antenna with inset fed which can
operate at 2.4 GHz (IEEE 802.11b) & 5.8 GHz (IEEE 802.11a) WLAN applications. Various slot is
cut into the antenna structure which changes the surface current path resulting in dual resonant
frequency. Further by embedding any switch into a slot, reconfiguration can be achieved i.e. the
antenna can only be used in unlicensed 2.4 GHz band. The achieved directivity is greater than 5db and
the bandwidth obtained is much greater than the required bandwidth. The proposed antenna is
simulated using High Frequency Structure Simulator.
This paper represents design of a simple, small, microstrip rectangular patch antenna for 5G application. Today, the requirement of antenna for such application should have higher bandwidth, low cost, low profile and smaller in size. The dimension of antenna are length and width of 2.59 mm and 3.65 mm respectively and height of this antenna is 0.4 mm. This antenna is designed by using thin and easily available substrate is used i.e., FR4 epoxy (εr= 4.4) to achieve compactness and high gain which will improve antenna performance. This antenna is wideband antenna means it covers a large bandwidth which includes 23.9 GHz frequency and our VSWR is improved from the base paper i.e., from 1.7483 to 1.0759. The simulation results of return loss, VSWR, gain and radiation pattern of the proposed antenna have been presented and discussed. Measured results are also presented and they are in good match with simulated results. The simulation results are obtained through HFSS 14 software.
Compact Quad-band Antenna for WiMax Applicationijsrd.com
A single feed quad band compact rectangular microstrip antenna for Wi-max applications has been designed and developed. This antenna is incorporated by one c-shaped slot, one L-shaped slot & two I-shaped slot structure along the length on the patch. Four resonating frequencies are obtained at 2.5 GHz with return loss -25.01 dB, 3.5 GHz with return loss -17.9 dB, 4.9 GHz with return loss -25.74 dB and 5.8 GHz with return loss -28.32 dB. The size of the antenna has been reduced by 77.3% when compared to a conventional microstrip patch without slot. An extensive analysis of the return loss, radiation pattern and efficiency of the proposed antenna has been given in this paper. The characteristics of the designed structure is simulated by High frequency structure simulator (HFSS) software and implemented using RT DUROID dielectric substrate which has ϵr = 2.2 and h = 1.575mm. The proposed antenna leads to multi frequency operation makes it suitable for Wireless Communication applications.
Microstrip patch antenna with defected ground structure for biomedical applic...journalBEEI
Proper narrowband antenna design for wearable devices in the biomedical application is a significant field of research interest. In this work, defected ground structure-based microstrip patch antenna has been proposed that can work for narrowband applications. The proposed antenna works exactly for a single channel of ISM band. The resonant frequency of the antenna is 2.45 GHz with a return loss of around -30 dB. The -10dB impedance bandwidth of the antenna is 20 MHz (2.442-2.462 GHz), which is the bandwidth of channel 9 in ISM band. The antenna has achieved a high gain of 7.04 dBi with an increase of 17.63% antenna efficiency in terms of realized gain by using defected ground structure. Three linear vector arrays of arrangement 1 2, 1 4 and 1 8 have been designed to validate the proposed antenna performances as an array. The proposed antenna is light weighted, low cost, easy to fabricate and with better performances that makes it suitable for biomedical WLAN applications.
A Low Profile CombinedArray Antenna for Wireless Applicationdbpublications
In wireless communication, micro strip antenna is used for various applications such as Wireless local area network, Bluetooth, Cordless Telephones and ISM band. Here a low profile microstrip antenna is to be designed. The antenna is constructed with FR4 substrate having relative permittivity of 4.4 and thickness of 1.6 mm. The unique (symmetric) array design enhances the narrow bandwidth and gain. The design results in extended WLANin X-band applications. Using High Frequency Structure Simulator (HFSS) software package, the antenna is simulated and dimensions are adjusted to achieve the desired resonant frequencies for desired operation.
Bandwidth Improvement of UWB Microstrip Antenna Using Finite Ground PlaneIJERA Editor
Microstrip antennas play a vital role in communication system. It is required in high performance wireless applications. But due to its resonant nature microstrip antennas have some considerable drawbacks like narrowband performance. Extensive study has been carried out on microstrip patch antennas in the recent past, but it still have large scope for improvement in the near future. To overcome narrow bandwidth problem, number of methods and techniques have been suggested and investigated, keeping in mind that the basic advantages of microstrip antenna should not be altered such as low profile, light weight, low cost and simple printed circuit structure. The area of investigation includes modification in geometrical shape of the antenna, use of resonators, use of dipole, and many other parameters. This paper presents a comparison between conventional microstrip antenna and microstip antenna with finite ground plane at ultra wideband. HFSS simulation tool is used here for antenna simulation. For feeding purpose microstrip feed line is used (50Ω). Optimized result provides impedance bandwidth of 7.2GHz with VSWR<2, operating frequency range is from 6.5GHz to 13.7GHz. Proposed antenna is useful for many ultra wideband applications. =
Coplanar waveguide-fed ultra-wideband antenna with WLAN bandnooriasukmaningtyas
A modified coplanar waveguide fed ultra-wideband antenna with extended transmission band to WLAN frequency is investigated. The proposed antenna consists of a modified semi-circular patch and staircase of ground plane. The prototype is constructed on a low cost FR4 substrate. The overall dimensions of proposed UWB antenna are 34 mm x 40 mm. The result has been shown that the proposed antenna archives low VSWR over transmission bandwidth from 2.10-12.7 GHz to cover both WLAN and UWB bands. The average gain is 3.87 dBi. It depicts nearly omni-directional radiation pattern like dipole antenna. Moreover, the fabricated prototype antenna shows a good agreement between the simulated and measured results. It is illustrated that our proposed technique is a good choice for designing any structure of microstrip antenna which appropriate to use for many wireless communication systems.
Cube satellite missions perform innovative scientific experiments on a low cost developmental platform but
have an inherent limitation of size and space. This restricts the total available solar power that can be
harnessed and as a result, the radio links operate on stringent power budgets. For improving the available
margins for communication in such satellites, it is desirable to improve upon the antenna system
performance at the ground station used for the establishment of the links with the satellite. This can be
achieved by improving the forward gain, the forward to backward ratio and the directivity of the antenna.
This paper describes the electrical simulations and the performance evaluation of the one unit, two unit and
four unit circularly polarized crossed Yagi-Uda antenna array designed for communication with amateur
radio (HAM) satellites operating over the 434 MHz to 438 MHz Amateur UHF band. The electro-magnetic
model has been developed using the 4NEC2 software. The simulations have been validated with the
practical field testing performed for estimating the SWR, antenna gain, the forward to backward ratio and
radiation pattern for the antenna system.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
ER Publication,
IJETR, IJMCTR,
Journals,
International Journals,
High Impact Journals,
Monthly Journal,
Good quality Journals,
Research,
Research Papers,
Research Article,
Free Journals, Open access Journals,
erpublication.org,
Engineering Journal,
Science Journals,
Design and Simulation of Compact Wideband Rectangular Dielectric Resonator An...ijsrd.com
An objective of the paper is to optimize the parameters, and simulation analysis of compact wideband rectangular dielectric resonator antenna (RDRA). In this paper, a compact wideband, rectangular dielectric resonator antenna is presented using relatively low dielectric constant material and using double microstrip patch. The rectangular DRA is fed with a modified stepped microstrip feed to ensure efficient coupling between the RDRA and the feeder. The performance of the proposed antenna has been significantly improved by loading the RDRA with two narrow conducting metallic strips of suitable widths, which results in dual-resonance excitation and leads to a wider operating bandwidth (16.274-18.200 GHz). The frequency characteristics and radiation performance of the proposed antenna are successfully optimized. Design and simulation results are in excellent agreement.
Design of Reconfigurable Microstrip Patch Antenna for WLAN ApplicationEditor IJMTER
In this paper we propose a rectangular microstrip patch antenna with inset fed which can
operate at 2.4 GHz (IEEE 802.11b) & 5.8 GHz (IEEE 802.11a) WLAN applications. Various slot is
cut into the antenna structure which changes the surface current path resulting in dual resonant
frequency. Further by embedding any switch into a slot, reconfiguration can be achieved i.e. the
antenna can only be used in unlicensed 2.4 GHz band. The achieved directivity is greater than 5db and
the bandwidth obtained is much greater than the required bandwidth. The proposed antenna is
simulated using High Frequency Structure Simulator.
This paper represents design of a simple, small, microstrip rectangular patch antenna for 5G application. Today, the requirement of antenna for such application should have higher bandwidth, low cost, low profile and smaller in size. The dimension of antenna are length and width of 2.59 mm and 3.65 mm respectively and height of this antenna is 0.4 mm. This antenna is designed by using thin and easily available substrate is used i.e., FR4 epoxy (εr= 4.4) to achieve compactness and high gain which will improve antenna performance. This antenna is wideband antenna means it covers a large bandwidth which includes 23.9 GHz frequency and our VSWR is improved from the base paper i.e., from 1.7483 to 1.0759. The simulation results of return loss, VSWR, gain and radiation pattern of the proposed antenna have been presented and discussed. Measured results are also presented and they are in good match with simulated results. The simulation results are obtained through HFSS 14 software.
Compact Quad-band Antenna for WiMax Applicationijsrd.com
A single feed quad band compact rectangular microstrip antenna for Wi-max applications has been designed and developed. This antenna is incorporated by one c-shaped slot, one L-shaped slot & two I-shaped slot structure along the length on the patch. Four resonating frequencies are obtained at 2.5 GHz with return loss -25.01 dB, 3.5 GHz with return loss -17.9 dB, 4.9 GHz with return loss -25.74 dB and 5.8 GHz with return loss -28.32 dB. The size of the antenna has been reduced by 77.3% when compared to a conventional microstrip patch without slot. An extensive analysis of the return loss, radiation pattern and efficiency of the proposed antenna has been given in this paper. The characteristics of the designed structure is simulated by High frequency structure simulator (HFSS) software and implemented using RT DUROID dielectric substrate which has ϵr = 2.2 and h = 1.575mm. The proposed antenna leads to multi frequency operation makes it suitable for Wireless Communication applications.
Microstrip patch antenna with defected ground structure for biomedical applic...journalBEEI
Proper narrowband antenna design for wearable devices in the biomedical application is a significant field of research interest. In this work, defected ground structure-based microstrip patch antenna has been proposed that can work for narrowband applications. The proposed antenna works exactly for a single channel of ISM band. The resonant frequency of the antenna is 2.45 GHz with a return loss of around -30 dB. The -10dB impedance bandwidth of the antenna is 20 MHz (2.442-2.462 GHz), which is the bandwidth of channel 9 in ISM band. The antenna has achieved a high gain of 7.04 dBi with an increase of 17.63% antenna efficiency in terms of realized gain by using defected ground structure. Three linear vector arrays of arrangement 1 2, 1 4 and 1 8 have been designed to validate the proposed antenna performances as an array. The proposed antenna is light weighted, low cost, easy to fabricate and with better performances that makes it suitable for biomedical WLAN applications.
A Low Profile CombinedArray Antenna for Wireless Applicationdbpublications
In wireless communication, micro strip antenna is used for various applications such as Wireless local area network, Bluetooth, Cordless Telephones and ISM band. Here a low profile microstrip antenna is to be designed. The antenna is constructed with FR4 substrate having relative permittivity of 4.4 and thickness of 1.6 mm. The unique (symmetric) array design enhances the narrow bandwidth and gain. The design results in extended WLANin X-band applications. Using High Frequency Structure Simulator (HFSS) software package, the antenna is simulated and dimensions are adjusted to achieve the desired resonant frequencies for desired operation.
Bandwidth Improvement of UWB Microstrip Antenna Using Finite Ground PlaneIJERA Editor
Microstrip antennas play a vital role in communication system. It is required in high performance wireless applications. But due to its resonant nature microstrip antennas have some considerable drawbacks like narrowband performance. Extensive study has been carried out on microstrip patch antennas in the recent past, but it still have large scope for improvement in the near future. To overcome narrow bandwidth problem, number of methods and techniques have been suggested and investigated, keeping in mind that the basic advantages of microstrip antenna should not be altered such as low profile, light weight, low cost and simple printed circuit structure. The area of investigation includes modification in geometrical shape of the antenna, use of resonators, use of dipole, and many other parameters. This paper presents a comparison between conventional microstrip antenna and microstip antenna with finite ground plane at ultra wideband. HFSS simulation tool is used here for antenna simulation. For feeding purpose microstrip feed line is used (50Ω). Optimized result provides impedance bandwidth of 7.2GHz with VSWR<2, operating frequency range is from 6.5GHz to 13.7GHz. Proposed antenna is useful for many ultra wideband applications. =
Coplanar waveguide-fed ultra-wideband antenna with WLAN bandnooriasukmaningtyas
A modified coplanar waveguide fed ultra-wideband antenna with extended transmission band to WLAN frequency is investigated. The proposed antenna consists of a modified semi-circular patch and staircase of ground plane. The prototype is constructed on a low cost FR4 substrate. The overall dimensions of proposed UWB antenna are 34 mm x 40 mm. The result has been shown that the proposed antenna archives low VSWR over transmission bandwidth from 2.10-12.7 GHz to cover both WLAN and UWB bands. The average gain is 3.87 dBi. It depicts nearly omni-directional radiation pattern like dipole antenna. Moreover, the fabricated prototype antenna shows a good agreement between the simulated and measured results. It is illustrated that our proposed technique is a good choice for designing any structure of microstrip antenna which appropriate to use for many wireless communication systems.
IMPEDANCE MATCHED COMPACT ZIGZAG MULTIBAND INVERTED-F ANTENNA FOR WI-FI, MOBI...ijasuc
Multiband loaded inverted-F antennas suitable to be applied in a portable device as an internal antenna
having high gain property for mobile WiMAX , Wi-Fi, Bluetooth and WLAN operations are presented.
Numerical simulation is carried out using method of moments in Numerical Electromagnetic Code
(NEC-2). The proposed dual inverted-F antenna is suitable for 3.5/5 GHz and compact triple band
inverted-F antenna is for 2.4/3.5/5.2 GHz operations. Total areas occupied by the antennas are
24mm×37mm and 29mm×37mm in case of dual IFA and triple IFA respectively. The antennas contain
an incredibly high peak gain of 7.72 dBi at 5 GHz band and the gain variations at all frequency bands
are less than 1 dBi . In addition, the antennas have satisfactory radiation characteristics at all the
frequency bands. Due to compact area occupied, the proposed antennas are promising to be embedded
within the different portable devices.
IMPEDANCE MATCHED COMPACT ZIGZAG MULTIBAND INVERTED-F ANTENNA FOR WI-FI, MOBI...ijasuc
Multiband loaded inverted-F antennas suitable to be applied in a portable device as an internal antenna
having high gain property for mobile WiMAX , Wi-Fi, Bluetooth and WLAN operations are presented.
Numerical simulation is carried out using method of moments in Numerical Electromagnetic Code
(NEC-2). The proposed dual inverted-F antenna is suitable for 3.5/5 GHz and compact triple band
inverted-F antenna is for 2.4/3.5/5.2 GHz operations. Total areas occupied by the antennas are
24mm×37mm and 29mm×37mm in case of dual IFA and triple IFA respectively. The antennas contain
an incredibly high peak gain of 7.72 dBi at 5 GHz band and the gain variations at all frequency bands
are less than 1 dBi . In addition, the antennas have satisfactory radiation characteristics at all the
frequency bands. Due to compact area occupied, the proposed antennas are promising to be embedded
within the different portable devices.
Design of a Dual-Band Microstrip Patch Antenna for GPS,WiMAX and WLANIOSR Journals
Abstract : The A multi band microstrip patch antenna has been designed for GPS,WiMAX and WLAN applications. The proposed antenna is designed by using substrate of RT duroid having permittivity of about 2.2 and loss tangent of 1.The substrate is having thickness of 6mm at which a trapezoidal patch antenna with V slot has been introduced in this paper. The designing results like S11 parameter return loss,VSWR and field pattern is plotted successfully. The obtained result is having a two band resonance with S11 less then -10dB and VSWR less than 2. So a dual band trapezoidal microstrip patch antenna has been designed and all results are plotted.Simmulating software used is IE3D. Keywords - V-shape slot, RT duroid, Dual band, WLAN, WiMAX,
Design of a Dual-Band Microstrip Patch Antenna for GPS,WiMAX and WLAN.IOSR Journals
The A multi band microstrip patch antenna has been designed for GPS,WiMAX and WLAN
applications. The proposed antenna is designed by using substrate of RT duroid having permittivity of about 2.2
and loss tangent of 1.The substrate is having thickness of 6mm at which a trapezoidal patch antenna with V slot
has been introduced in this paper. The designing results like S11 parameter return loss,VSWR and field pattern
is plotted successfully. The obtained result is having a two band resonance with S11 less then -10dB and VSWR
less than 2.
So a dual band trapezoidal microstrip patch antenna has been designed and all results are plotted.Simmulating
software used is IE3D.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
Ethnobotany and Ethnopharmacology:
Ethnobotany in herbal drug evaluation,
Impact of Ethnobotany in traditional medicine,
New development in herbals,
Bio-prospecting tools for drug discovery,
Role of Ethnopharmacology in drug evaluation,
Reverse Pharmacology.
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DESIGN OF A YAGI-UDA ANTENNA WITH GAIN AND BANDWIDTH ENHANCEMENT FOR WI-FI AND WI-MAX APPLICATIONS
1. International Journal of Antennas (JANT) Vol.2, No. 1, January 2016
DOI: 10.5121/jant.2016.2101 1
DESIGN OF A YAGI-UDA ANTENNA WITH
GAIN AND BANDWIDTH ENHANCEMENT
FOR WI-FI AND WI-MAX APPLICATIONS
Vinay Bankey1
and N. Anvesh Kumar2
1
Department of ECE, VNIT, Nagpur, India as a Lab Engineer
2
Department of ECE, VNIT, Nagpur, India as a Research Scholar
ABSTRACT
There are various patch antennas used for Wi-Fi and Wi-MAX applications. But, the problems with them
are low gain, low power handling capacity and hence, conventional yagi-uda antennas are used.
Conventional yagi-uda antennas are used in applications where high gain and directionality are
required. Generally, numbers of directors are added to increase gain of these antennas. But, here we
present modified yagi-uda antennas, in which the gain and bandwidth can be enhanced by not adding
additional directors.
In this paper, we initially discuss the designs of various yagi-uda antennas with uniform, non-uniform
spacings between directors and then we discuss their gain and bandwidth enhancement by various
approaches. Simulation results show that, the proposed techniques can enhance gain as well as
bandwidth when compared with the traditional yagi-uda antennas.
Index Terms
Bandwidth, FEKO, gain, non-uniform spacing, uniform spacing, Wi-Fi, Wi-MAX.
1. INTRODUCTION
In recent years, Wi-Fi and Wi-MAX technologies are playing a vital role in wireless
communication because of their advantages like high speed data transfer and anytime, anywhere
internet access. There are various patch antennas proposed in [1-3], for these applications. But,
the problems with them are low gain and low power handling capacity. The drawback of low
gain and low power handling can be overcome by using conventional yagi-uda antennas.
1.1. WI-FI AND WI-MAX BANDS
Basically, Wi-Fi and Wi-MAX technologies use unlicensed and licensed spectrums for wireless
communication. There are five Wi-MAX bands available in all over the world. Those frequency
bands are 2.3GHz, 2.5GHz, 3.3GHz, 3.5GHz and 5.8GHz. The links mentioned in [4], can also
give us a clear idea about Wi-MAX bands and their channels in different frequency bands.
Different countries use similar or different frequency bands for Wi-MAX applications. For
example, USA uses 3 bands and Canada uses 4 bands [5].
There are two bands dedicated for Wi-Fi applications. One is 2.4GHz band and another one is
5GHz band. The frequency band of 5GHz covers frequencies ranging from 5.1GHz to 5.8GHz.
All over the world, 2.4GHz band is not having any major power limitation. But, if we consider
the 5GHz band, there is a power limit that varies from country to country [6]. The 2.4GHz band
covers frequencies ranging from 2.401GHz to 2.484GHz as shown in figure 1.
2. International Journal of Antennas (JANT) Vol.2, No. 1, January 2016
2
Figure 1: Wi-Fi bands [7].
1.2. CONVENTIONAL YAGI-UDA ANTENNAS
Conventional yagi-uda antennas were invented in 1926 by Shintaro Uda of Tohoku imperial
university, Japan along with his colleague Hidetsugu Yagi. These antennas are used in HF (3-
30MHz), VHF (30-300MHz), and UHF (300-3000MHz) ranges. Basically, yagi-uda antennas
consist of three different types of linear dipole elements as shown in figure 2.
Figure 2: Conventional yagi-uda antenna with various linear dipole elements.
The elements are active element, reflectors and directors [8, 9]. An active element is the one to
which the source or excitation is applied. Generally, length (Lac) of this element is slightly less
than λ/2 i.e. ranges from 0.45λ to 0.49λ. Active element is also known as a feeder or a driven
dipole. Length of reflector (Lr) is 5% greater than the length of active element. Having a length
greater than the active element causes good reflections towards forward direction. Basically,
more than one reflector can be used, but it does not add any advantage specifically. A reflector
is located behind active element at a distance (Sra) of 0.25λ. In the designs of yagi-uda
antennas, directors play a key role in achieving better gain and directivity. Usually, their length
is 5% smaller than the active element i.e. lies between 0.4λ to 0.45λ. Generally, gain is
enhanced by adding number of directors as well as by optimizing the spacing between them. In
the standard designs, spacing between the directors and the spacing between an active element,
directors varies between 0.35λ to 0.4λ. Radius (a) of each element is 0.00425λ [8].
2. RELATED WORK
There are various yagi-uda antennas presented in [10-13]. The proposed antennas are covering
frequencies around 2.4GHz for different applications. In the paper [10], the authors discuss
about a miniaturized yagi antenna for GSM, WLAN and Wi-MAX applications. The proposed
3. International Journal of Antennas (JANT) Vol.2, No. 1, January 2016
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antenna for WLAN and Wi-MAX applications is covering 10dB return loss frequencies ranging
from 2.25GHz to 2.72GHz. The authors in [11], present a 10-element (with 8 directors)
conventional yagi-uda antenna for WLAN applications. The proposed antenna is covering
frequencies ranging from 1.8GHz to 2.4GHz with a gain of 13dBi. They carried out simulation
using method of moments based EM simulation software called SuperNec v2.9. The proposed
antenna in [11] is also covering bands other than WLAN and moreover, it uses 8 directors to
achieve a gain of 13dBi.
Figure 3: 10-element yagi-uda antenna [11].
In this paper, we discuss various yagi-uda antennas operating at 2.45GHz. Proposed antennas
cover complete Wi-Fi 2.4GHz band along with few channels of Wi-MAX 2.3GHz and 2.5GHz
bands. With the proposed gain enhancement approaches, we are able to achieve a maximum
gain of 12.30dBi with 4 directors. Simulations of these antennas are performed on method of
moments based EM structure simulator software called FEKO suite 6.3.
3. DESIGN OF CONVENTIONAL YAGI-UDA ANTENNAS
In this paper, we initially focus on the designs of conventional yagi-uda antennas with 4
directors as shown in figure 2. Here, we have selected 4 directors for better gain and bandwidth.
First of all, we consider uniform spacing between the directors and then we focus on non-
uniform spacing.
3.1. UNIFORM SPACING BETWEEN DIRECTORS
In this paper, for better understanding of the designs, we have mentioned all the dimensions in
terms of ‘λ’. Here, uniform spacing between the directors is denoted by ‘Sad’ and it is assumed
as 0.35λ. Design of the proposed uniform spaced yagi-uda antenna with 4 directors in FEKO is
shown in figure 4.
Figure 4: Conventional yagi-uda antenna with 4 directors.
Before discussing various yagi-uda antennas, initially we need to know the optimized
dimensions of ‘Lr’ (≥ λ/2), ‘Lac’ (0.45λ-0.49λ) and ‘Ld’ (0.4λ-0.45λ) of a conventional yagi-
uda antenna for Wi-Fi and Wi-MAX applications. From the basic knowledge of conventional
yagi-uda antennas, we have tried different possible combinations with the lengths of reflector,
active element and directors. Results of designs having different possible lengths are shown in
Table I.
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TABLE I. ‘Sra’=0.25*λ, ‘Sad1’=’Sad2’=’Sad3’=’Sad4’=’Sad’=0.35*λ, where ‘Lr’, ‘Lac’ and ‘Ld’
are varying
case Lr Lac Ld Gain Gain
(dBi)
-10dB ranges
(GHz)
-10 dB Bandwidth
(GHz)
I 0.55*λ 0.5*λ 0.4*λ 8.535 9.31 2.115-2.308 0.193
II 0.525*λ 0.5*λ 0.4*λ 9.246 9.66 2.143-2.298 0.155
III 0.525*λ 0.475*λ 0.4*λ 9.213 9.64 2.215-2.418 0.203
IV 0.5*λ 0.45*λ 0.4*λ 10.32 10.14 2.324-2.565 0.241
V 0.475*λ 0.425*λ 0.4*λ 11.60 10.64 2.440-2.600 0.160
If we look at the results shown in table I, designs with cases I, II, III and V are not suitable for
our applications. Because, these designs are covering frequencies other than Wi-Fi and Wi-
MAX bands. However, case V antenna design can be used only in Wi-MAX 2.5GHz band for
few channels. So, for our applications, antenna presented in case IV is suitable because, it is
covering complete Wi-Fi 2.4GHz band along with few Wi-MAX channels. Here, we got the
dimensions of ‘Lr’, ‘Lac’ and ‘Ld’ as shown in table I case IV. Various plots of the proposed
design having dimensions mentioned in table I case IV are shown in figures 5 (a) and (b).
(a)
(b)
Figure 5 (a): Reflection coefficient vs. frequency plot (b). Polar plot of the proposed antenna at 2.45GHz,
for table I case IV dimensions.
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From the results of table I, we get the dimensions of different element lengths. Now, let us see
why we have considered the possible uniform spacing between directors (Sad) as 0.35λ. Results
of designs having different uniform spacings are presented in table II.
TABLE II. ‘Lr’=0.5*λ, ‘Lac’=0.45*λ, ‘Ld’=0.4*λ, ‘Sra’=0.25*λ, where ‘Sad’ is varying
case Sad Gain Gain
(dBi)
-10dB Ranges
(GHz)
-10dB Bandwidth
(GHz)
I 0.35* λ 10.32 10.14 2.324-2.565 0.241
II 0.38*λ 10.81 10.34 2.316-2.52 0.204
III 0.4*λ 11.61 10.65 2.318-2.493 0.175
IV 0.425* λ 11.50 10.61 2.322-2.466 0.144
If we focus on the results shown in table II, it is clear that when ‘Sad’ is 0.35λ, then only we are
able to achieve complete Wi-Fi 2.4GHz band along with few channels of Wi-MAX 2.3GHz and
2.5GHz bands. Note that, the antenna designs with dimensions discussed in table I case IV and
table II case I are same. Here, as we keep on increasing uniform spacing, it is understood that,
gain increases but the bandwidth decreases.
Therefore, we can highlight that, only the design discussed in table II case I is useful for Wi-Fi
and Wi-MAX applications. However, case II and III designs can be used only for Wi-Fi
applications. In table I and II, we present the results of possible uniform spacings between the
directors. In these cases, it is observed that the antenna design with table II case I dimensions is
most suitable for our applications. Now, let us consider non-uniform spacing between the
directors.
3.2. NON-UNIFORM SPACING BETWEEN DIRECTORS
As discussed earlier, spacing between the directors and the spacing between a director and an
active element lies between 0.35λ to 0.4λ. Previously, we focused only on uniform spacing
between the directors. Here, we examine different possible non-uniform spacing combinations
for our applications. Different non-uniform spacing outcomes are shown in table III.
TABLE III. ‘Lr’=0.5*λ, ‘Lac’=0.45*λ, ‘Ld’=0.4*λ, ‘Sra’=0.25*λ, where ‘Sad1’, ‘Sad2’, ‘Sad3’
and ‘Sad4’ are varying
case Sad1 Sd Sd1 Sd2 Gain Gain
(dBi)
-10dB
Ranges
(GHz)
-10dB
Bandwidth
(GHz)
I 0.35*λ 0.73*λ 1.13*λ 1.53*λ 11.350 10.55 2.334-2.519 0.185
II 0.35*λ 0.73*λ 1.06*λ 1.46*λ 10.233 10.10 2.321-2.549 0.228
III 0.35*λ 0.73*λ 1.06*λ 1.39*λ 10.556 10.235 2.328-2.549 0.221
IV 0.35*λ 0.70*λ 1.03*λ 1.36*λ 10.430 10.183 2.327-2.57 0.243
V 0.40*λ 0.78*λ 1.13*λ 1.46*λ 9.897 9.955 2.315-2.527 0.212
VI 0.35*λ 0.73*λ 1.13*λ 1.48*λ 11.17 10.48 2.325-2.527 0.202
Let us consider the results shown in table III. Design with table III case I dimensions can be
used only for Wi-Fi applications. Antenna design with table III case VI dimensions has
somewhat less gain but more bandwidth than the design with table III case I dimensions.
Antenna design with table III case IV dimensions is providing similar results in terms of gain as
6. International Journal of Antennas (JANT) Vol.2, No. 1, January 2016
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well as bandwidth, when comparing with the antenna discussed in table II case I. If we focus on
the results discussed in table III, it is clear that the results are not better than the results obtained
in table II case I. So, for our dual applications discussed non-uniform spacing designs are not
giving proper gain, bandwidth and hence from the next discussion onwards our designs deal
only with uniform spacings between the directors.
As per the designs with 4 directors (uniform spacing and non-uniform spacing) are concerned,
design with table II case I dimensions is the best design for our application. So far, we have
been dealing designs with 4 directors. In the next section, we observe the response of proposed
design, when the number of directors is varied.
3.3. INCREASING NUMBER OF DIRECTORS
Here, our aim is to compare the results obtained in this section with the results obtained in the
modified yagi-uda antenna design section. Design results of proposed antennas with a variation
in number of directors are given in table IV.
TABLE IV. ‘Lr’=0.5*λ, ‘Lac’=0.45*λ, ‘Ld’=0.4*λ, ‘Sra’=0.25*λ, ‘Sad’=0.35*λ, where the
number of directors are varying
No. of Directors Gain Gain (dBi) -10dB Ranges (GHz) -10dB Bandwidth (GHz)
3 9.07 9.58 2.32-2.538 0.218
4 10.32 10.14 2.324-2.565 0.241
5 12.70 11.04 2.331-2.54 0.209
6 14.55 11.63 2.323-2.513 0.190
7 15.27 11.84 2.323-2.528 0.205
8 16.94 12.29 2.328-2.547 0.219
If we observe the results of designs shown in table IV, yagi-uda antenna with 3 directors is
giving quite low gain. Proposed antenna with 6 directors is giving a maximum gain of 11.63dBi
and a 10dB return loss bandwidth of 0.190GHz. Various plots of proposed yagi-uda antenna
with 6 directors are presented in figures 6 (a) and (b).
(a)
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(b)
Figure 6 (a): Reflection coefficient vs. frequency plot (b). Polar plot at 2.45GHz of the proposed
yagi-uda antenna with 6 directors.
Design with 7 directors is providing a maximum gain of 11.84dBi and a 10dB return loss
bandwidth of 0.205GHz. Obtained results in this case are better than the yagi-uda antenna with
6 directors. Yagi-da antenna with 8 directors is also yielding improved gain and bandwidth than
all other cases as shown in table IV. From the observation, as we increase number of directors,
gain as well as size of the antenna increases. In this paper, our focus is to enhance the gain by
keeping same 4 directors as well as maintaining the same bandwidth (obtained in table II case I)
as minimum bandwidth. At the same time, we need to maintain the same 2.3GHz and 2.5GHz -
10dB cut-offs as in the case of yagi-uda antenna with table II case I dimensions, so that it is
useful for Wi-Fi and Wi-MAX applications.
4. DESIGN OF MODIFIED YAGI-UDA ANTENNAS
In this section, we discuss different approaches to enhance the gain by not disturbing the
bandwidth obtained in table II case I. To obtain better performance in terms of gain and
bandwidth, we replace reflector element by better reflectors like parabolic plate or rectangular
plate of good conducting material.
4.1. REPLACING REFLECTOR ELEMENT BY A PARABOLIC PLATE
Here, we present designs of modified yagi-uda antennas, in which the reflector element is
replaced by a parabolic plate. In this case, ‘Sra’ is a distance between the centre of the parabolic
plate to the active element, which is also 0.25*λ. Proposed parabolic plate and modified antenna
designs are shown in figures 7 (a) and (b).
(a)
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(b)
Figure 7. (a): Proposed parabolic plate with a radius ‘r’ and depth ‘d’ in place of reflector
element. Figure 7. (b): Proposed Modified yagi-uda antenna design with 4 directors in FEKO.
To have improved performance than the conventional yagi-uda antenna, diameter (D) of the
parabolic plate must be greater than the length of active element. In the initial design, we
assume radius (r) as ‘Lr/2’ and then we make changes in depth. In the next level of the design,
we increase radius (r) and then we vary the depth as shown in below tables. To avoid
complexity, here also we have mentioned parabolic structure dimensions in terms of ‘Lr’.
Different combinations of radius ‘Lr/2’ and depth (d) results are presented in table V.
TABLE V. ‘Lr’=0.5*λ, ‘Lac’=0.45*λ, ‘Ld’=0.4*λ, ‘Sra’=0.25λ, ‘Sad’=0.35*λ, where ‘r’ and
‘d’ are varying
If we look at results shown in table V, it is clear that by replacing a reflector with a parabolic
plate, there is enhancement in gain than the conventional yagi-uda antenna discussed in table II
case I. There is one more point to observe is that, as we decrease the depth (d), gain decreases
slightly but the bandwidth increases considerably. Modified yagi-uda antenna with radius ‘Lr/2’
and depth ‘Lr/5’ is achieving a maximum gain of 11.14dBi, which is higher than the gain of
yagi-uda antenna with 5 directors (11.04dBi). But, the proposed antenna design is not covering
Wi-Fi and Wi-MAX bands. Antenna design with radius ‘Lr/2’ and depth ‘Lr/30’ is also yielding
higher gain but less bandwidth than the yagi-uda design discussed in table II case I. This design
is providing better bandwidth than the design with radius ‘Lr/2’ and depth ‘Lr/5’. Here, we need
a modified yagi-uda antenna with higher gain and bandwidth than the antenna discussed in table
II case I. To achieve the required goal, let us increase the radius of parabolic plate. Design
results of the antenna with increased radius and variation in depth are shown in table VI.
TABLE VI. ‘Lr’=0.5*λ, ‘Lac’=0.45*λ, ‘Ld’=0.4*λ, ‘Sra’=0.25λ, ‘Sad’=0.35*λ, where ‘r’
and ‘d’ are varying
Radius
(r)
Depth
(d)
Gain Gain
(dBi)
-10dB Ranges
(GHz)
-10dB Bandwidth
(GHz)
Lr/2 Lr/5 13.00 11.14 2.348-2.476 0.128
Lr/2 Lr/10 12.50 10.97 2.348-2.530 0.182
Lr/2 Lr/30 12.19 10.86 2.345-2.546 0.201
Radius (r) Depth (d) Gain Gain
(dBi)
-10dB Ranges
(GHz)
-10dB Bandwidth
(GHz)
(2*Lr)/3 Lr/5 14.80 11.70 2.28-2.479 0.199
(2*Lr)/3 Lr/10 14.50 11.61 2.295-2.531 0.236
(2*Lr)/3 Lr/30 14.22 11.53 2.297-2.545 0.248
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In this case, with the increment in radius, gain as well as bandwidth increases. Design with
radius ‘(2*Lr)/3’ and depth ‘Lr/30’ is giving a maximum gain of 11.53dBi, which is higher than
the yagi-uda antenna discussed in table II case I (10.14dBi). At the same time, it is also higher
than the yagi-uda antenna with 5 directors (11.04dBi). In this case, we are covering complete
Wi-MAX 2.3GHz and Wi-Fi 2.4GHz bands, which are not covered by the conventional yagi-
uda antenna discussed in table II case I. Here also we are getting improved gains and
bandwidths. Let us increase the radius further. Design results the proposed antenna with radius
‘Lr’ and different values of depths are presented in table VII.
TABLE VII. ‘Lr’=0.5*λ, ‘Lac’=0.45*λ, ‘Ld’=0.4*λ, ‘Sra’=0.25λ, ‘Sad’=0.35*λ, where ‘r’
and ‘d’ are varying
Consider the design results shown in table VII. Design with radius ‘Lr’ and depth ‘Lr/5’ is
providing a maximum gain of 12.30dBi, which is more than the yagi-uda antenna with 8
directors (12.29dBi). In this case also, we are achieving complete Wi-MAX 2.3GHz and Wi-Fi
2.4GHz bands. The design with radius ‘Lr’ and depth ‘Lr/30’ is giving a maximum gain of
12.10dBi, which is higher than the yagi-uda antenna with 6 directors (11.63dBi), 7 directors
(11.84dBi). Even, it is almost maintaining the same 2.5GHz -10dB cutoff (2.557 GHz) with -
10dB cutoff of the yagi-uda antenna (2.565GHz) discussed in table II case I. Various plots of
the proposed antenna with radius ‘Lr’ and depth ‘Lr/30’ are shown in figures 8 (a) and (b).
(a)
Radius
(r)
Depth (d) Gain Gain
(dBi)
-10dB Ranges
(GHz)
-10dB Bandwidth
(GHz)
Lr Lr/5 17.00 12.30 2.287-2.552 0.265
Lr Lr/10 16.60 12.20 2.291-2.554 0.263
Lr Lr/30 16.20 12.10 2.294-2.557 0.263
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(b)
Figure 8 (a): Reflection coefficient vs. frequency plot (b). Polar plot at 2.45GHz, of the
Modified yagi-uda antenna, when ‘r’ as ‘Lr’ and ‘d’ as ‘Lr/30.
Here, we can state that, without increasing number of directors it is possible to enhance the gain
as well as bandwidth. So, for our Wi-Fi and Wi-MAX applications proposed antenna designs
discussed in table VII are most suitable. In the next discussion, we replace reflector element by
a rectangular plate.
4.2. REPLACING REFLECTOR BY RECTANGULAR PLATE
Here, we discuss the response of modified yagi-uda antennas, when the reflector element is
replaced by a rectangular plate having length (L) and width (W) as shown in figure 9 (a). In this
case ‘Sra’ is simply a distance between the rectangular plate to the active element, which is also
0.25*λ. Arrangement of the conventional yagi-uda antenna with rectangular plate is shown in
figure 9 (b).
Figure 9 (a): Proposed rectangular plate with Length ‘L’ and width ‘W’ in place of reflector
element.
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Figure 9 (b): Proposed Modified yagi-da antenna with rectangular plate.
Design results of the rectangular plate with possible combinations of Width (W) and Lengths
(L) are shown in table VIII.
TABLE VIII. ‘Lr’=0.5λ, ‘Lac’=0.45*λ, ‘Ld’=0.4*λ, ‘Sra’=0.25*λ, ‘Sad’=0.35*λ, where ‘L’ and
‘W’ are varying
Width (W) Length (L) Gain Gain (dBi) -10dB Ranges
(GHz)
-10dB Bandwidth
(GHz)
Lr/2 Lr 11.80 10.72 2.315-2.556 0.241
Lr/2 Lr*1.5 10.40 10.17 2.31-2.563 0.253
Lr Lr 12.90 11.11 2.311-2.548 0.237
Lr Lr*1.5 12.80 11.07 2.30-2.557 0.257
Lr*1.5 Lr*1.5 14.48 11.61 2.295-2.557 0.262
If we look at the results shown in table VIII, we get a maximum gain of 11.61dBi, which is
approximately equal to the conventional yagi-uda antenna with 6 directors (11.63dBi). In this
case also, the design is achieving more bandwidth and almost maintaining the same 2.5GHz -
10dB cutoff (2.557 GHz) with -10dB cutoff of the yagi-uda antenna (2.565GHz) discussed in
table II case I. Various plots of the proposed modified yagi-uda antenna with rectangular plate
having width ‘Lr*1.5’ and length ‘Lr*1.5’ are shown in figures 10 (a) and (b).
(a)
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(b)
Figure 10 (a): Reflection coefficient vs. frequency plot (b). Polar plot at 2.45GHz, of the modified yagi-
uda antenna, when ‘L’ and ‘W’ as 1.5*Lr.
Here also, we can state that, the proposed antenna design with rectangular plate having length
and widths as ‘1.5*Lr’ can also be used for our applications. Hence, we can conclude that, the
proposed designs in table VII and the design with rectangular plate having length and widths as
‘1.5*Lr’ are most suitable antennas for Wi-Fi and Wi-MAX applications.
5. CONCLUSION
In this paper, initially we discuss conventional yagi-uda antennas by considering uniform, non-
uniform spacing between directors. Here, we observed the problems associated with non-
uniform spacings and concluded that, the antenna design presented in table II case I is suitable
for our dual applications. Next, we varied the number of directors and noted that, as we increase
number of directors, gain as well as size of the antenna increases. After that, we replace the
reflector element by various structures. Out of this examinations, parabolic plate designs
discussed in table VII and the design with rectangular plate having length and widths as
‘1.5*Lr’, are giving increased gain and bandwidth than any other yagi-uda antennas. Finally, we
can state that, proposed designs in table VII and table VIII are most suitable antennas for Wi-Fi
and Wi-MAX applications. These kinds of designs are mostly useful in areas, where Wi-Fi and
Wi-MAX technologies are enabled.
REFERENCES
[1] Payal, R. Madhusudhan Goud, Komalpreet Kaur, “Design of Yagi-Uda Antenna using
Microstrip circuit”, International Journal of Computer Applivations(0975-8887), Volume 96-
No.24, June 2014.
[2] Priti N. Bhagat, V.B. Baru, “Slotted Patch Antennas with EBG Structure for ISM Band”, 2012
International Conference on Communication, Information & Computing Technology (ICCICT) ,
Oct. 19-20, Mumbai, India.
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[20] Mirishkar Sai Ganesh, “Optimization of radiation Pattern of Yagi-Uda antenna”, Edubeam
Multidisciplinary-Online Research Journal Vol-Xi, Issue-1, January-2014, ISSN 2320-6314.
[21] Tanner Gore, Keenan Rusk, Bijan Tehrani, “Physical Yagi-Uda antenna”.
[22] Ritsuo Nonoyama, Tadahiko Maeda, “Stability of Step-tapered Design Alteration in Radius of
elements on Radiation Characteristics of Yagi-Uda Antenna”, Proceedings of iWAT 2008,
Chila, Japan.
Authors
Vinay bankey was born in 23/12/1990, he received is M.Tech degree from
VNIT, Nagpur, India, in the field of Communication Systems Engineering.
Currently he is working as a Lab engineer in VNIT, ECE. His research fields
include microstrip antennas and wireless communications.
N. Anvesh Kumar was born in 06/03/1991, he received is B.Tech degree from
SSIT, Hyderabad, India. He received is M.Tech degree from VNIT, Nagpur,
India, in the field of Communication Systems Engineering. Currently he is a
Research Scholar in VNIT, ECE. His research fields include printed antennas,
Radars, microstrip antennas and RF circuits.