This document describes the implementation of a double-layer structure on an octagon microstrip yagi antenna (OMYA) to improve its performance at 5.8 GHz. The double-layer consists of two double positive (DPS) substrates placed above the OMYA. Simulation and experimental results show that the double-layer configuration increases the gain of the OMYA by 2.5 dB compared to without the double-layer. The measured bandwidth of the OMYA with double-layer is 14.6%, indicating the double-layer can increase both the gain and bandwidth of the OMYA.
A new look on CSI imperfection in downlink NOMA systems
- The document analyzes the performance of downlink non-orthogonal multiple access (NOMA) systems under imperfect channel state information (CSI) and Nakagami-m fading.
- It derives closed-form expressions for the outage probability of two users in such NOMA systems considering the joint impact of imperfect CSI and Nakagami-m fading.
- Monte Carlo simulations are conducted to verify the accuracy of the analytical outage probability expressions derived for the two users under the system and channel models considered.
PLANAR ACS FED DUAL BAND ANTENNA WITH DGS FOR WIRELESS APPLICATIONS
A novel Asymmetric Coplanar Strip (ACS) fed antenna with Defected Ground Structure (DGS) suitable for dual application is presented. The Method of Moments (MoM) based mentor graphics IE3D electromagnetic solver has been used for this design. Dual band operation has been obtained by modifying the ground plane of the proposed design with spur-slots. It has been fabricated and tested with the overall size of 21x15x1.6 mm3 The measured results indicate that the proposed antenna yields <-10dB impedance bandwidth of 13.13% and 9.86% which meets the requirement of 3.5GHz and 5.5GHz Wireless Local Area Network (WLAN) and World Wide Interoperability
Microwave Access (WiMAX) applications. The approximate lumped equivalent circuit extraction for the proposed DGS fed dual band antenna has been discussed in detail. Because of its stable radiation patterns with low cross polarization,miniature size, high average antenna gain of 2.5dBi and good electromagnetic characteristics, the proposed antenna is a promising candidate for dual mode wireless communication devices.
Comparative analysis of feeding techniques for cylindrical surrounding patch ...
In this research work, a cylindrical surrounding patch antenna (CSPA) with improved performance parameters based on inset feed method compared to other feed techniques has been proposed for 1.8 GHz applications. The designed and simulated CSPA is a rotary version of an initially designed rectangular planar patch antenna (RPPA). The RPPA is mounted on a cylindrical surface with radius (r) 10 mm which is an increased curvature for better -10 dB S-parameter (S 11 ), impedance band width (BW), voltage standing wave ratio (VSWR), radiation pattern, and gain. The copper radiating patch has been conformed on the surface of the grounded flexible polyimide substrate with relative permittivity (ε r ) 3.5 and thickness (h) 1.6 mm at normalized input impedance of 50 Ω. Results for the RPPA and the proposed CSPA have been compared with existing designs in terms of antenna size, resonant frequency (f r ), return loss (S 11 ), and gain while taking cognizance of the feeding techniques. The S 11 , BW, VSWR, and gain are-12.784 dB, 28 MHz, 1.8, and 4.81 dBi respectively for the rectangular planar patch antenna and -35.571 dB, 66 MHz, 1.5, and 3.74 dBi, respectively for the cylindrical surrounding patch antenna.
This document presents the design and optimization of a dual-frequency microstrip patch antenna using IE3D simulation software. A rectangular patch with two slots is used to create a second resonant TM0δ mode above the fundamental TM01 mode. IE3D's Fast EM and Powell optimizers are employed to optimize the geometric parameters and achieve maximum return losses of -36.5 dB at 7 GHz and -15 dB at 7.59 GHz with a 10 dB bandwidth. Simulation results for return loss, VSWR, and radiation patterns are provided and compared for the theoretical, Powell, and Fast EM optimized designs. The Fast EM optimization achieved the best performance and dual-band operation of the slotted microstrip patch antenna.
IRJET-Miniaturized Wide Bandwidth MIMO Dielectric Resonator Antenna using Def...
This document presents a miniaturized wide bandwidth multiple-input multiple-output (MIMO) dielectric resonator antenna (DRA) using a defective ground structure for ultra-wideband applications. The antenna is designed to operate at 6.9 GHz and achieves an ultra-wide bandwidth of 4.692 GHz from 5.92 to 10.62 GHz without interfering with wireless local area network frequencies. Three designs are analyzed and the optimized design uses two DRAs made of Rogers RO4350 substrate with a dimension of 29x29x2.295 mm3. A stub is placed between the DRAs to provide isolation and reduce mutual coupling. The defective ground structure enhances the bandwidth. Simulation results show the optimized design meets requirements
This document summarizes the design and study of a compact and wideband microstrip U-slot patch antenna for Wi-Max applications. The antenna was designed to operate in the 5.25GHz Wi-Max band with very low return loss. Design formulas are provided to calculate the dimensions of the rectangular microstrip patch antenna. Simulation results show the return loss is below -30dB from 5.15GHz to 5.85GHz, meeting the bandwidth requirements. The proposed antenna design achieves wideband operation using a 3-layer substrate with total thickness of 1.6mm.
This document summarizes the simulation of a compact microstrip patch antenna for Ku-band VSAT systems. The antenna uses a hexagonal patch with two triangular and one rectangular slot to reduce the size by 52.64% compared to a conventional rectangular patch antenna. Simulation results show the slotted antenna operates at two resonant frequencies, 9.50169 GHz and 13.0013 GHz, with return losses of -19.525 dB and -35.275 dB respectively. The slotted antenna achieves a frequency ratio of 1.3683, increased bandwidth, and gain between 1.50649 to 3.97715 dBi based on the simulation results. This compact dual-band antenna design has applications for wireless communications, satellite systems
Gain enhancement of dielectric resonator antenna for millimeter wave applicat...TELKOMNIKA JOURNAL
In this paper, dielectric resonator antenna (DRA) with enhanced gain operating on the higher
order mode (푇퐸훿15
푥 ) is presented. The dielectric resonator antenna with dielectric constant 휀푟 of 10 and
loss tangent of 0.002 is used. The DRA is fed by microstrip line through an aperture slot. The proposed
antenna is designed at 26 GHz and achieved a gain of 7.9 dBi with corresponding simulated radiation
efficiency of 93%. The impedance bandwidth of 1.5 GHz from 25.1 GHz to 26.6 GHz has been achieved.
The reflection coefficient, antenna gain, radiation patterns, and efficiency of the antenna are studied.
Simulations are performed using CST microwave studio, and their results are presented.
Comparative Analysis for Different Stack Shaped Microstrip Patch Antennaijsrd.com
A compact stack antenna consisting of square patch, loop couplers and inset feed line is reviewed in this work. This proposed design represents a stacked patch antenna having an arrangement of two substrates separated by an air gape and a coupling is provided using square loop structure. The structure is reviewed in two different directions firstly the feed arrangement is varied and secondly a variation in coupler structure is done to make the antenna work at multiple frequencies in UWB range. The simulation results of this work with different resonator structure and feed structures are presented and comparative analysis of these different arrangements is presented in this paper. Simulation results obtained from the proposed antenna for return loss, polar radiation and pattern voltage standing wave ratio (VSWR) shows its suitability for ultra wide band application.
A new look on CSI imperfection in downlink NOMA systemsjournalBEEI
- The document analyzes the performance of downlink non-orthogonal multiple access (NOMA) systems under imperfect channel state information (CSI) and Nakagami-m fading.
- It derives closed-form expressions for the outage probability of two users in such NOMA systems considering the joint impact of imperfect CSI and Nakagami-m fading.
- Monte Carlo simulations are conducted to verify the accuracy of the analytical outage probability expressions derived for the two users under the system and channel models considered.
PLANAR ACS FED DUAL BAND ANTENNA WITH DGS FOR WIRELESS APPLICATIONS jantjournal
A novel Asymmetric Coplanar Strip (ACS) fed antenna with Defected Ground Structure (DGS) suitable for dual application is presented. The Method of Moments (MoM) based mentor graphics IE3D electromagnetic solver has been used for this design. Dual band operation has been obtained by modifying the ground plane of the proposed design with spur-slots. It has been fabricated and tested with the overall size of 21x15x1.6 mm3 The measured results indicate that the proposed antenna yields <-10dB impedance bandwidth of 13.13% and 9.86% which meets the requirement of 3.5GHz and 5.5GHz Wireless Local Area Network (WLAN) and World Wide Interoperability
Microwave Access (WiMAX) applications. The approximate lumped equivalent circuit extraction for the proposed DGS fed dual band antenna has been discussed in detail. Because of its stable radiation patterns with low cross polarization,miniature size, high average antenna gain of 2.5dBi and good electromagnetic characteristics, the proposed antenna is a promising candidate for dual mode wireless communication devices.
Comparative analysis of feeding techniques for cylindrical surrounding patch ...IJECEIAES
In this research work, a cylindrical surrounding patch antenna (CSPA) with improved performance parameters based on inset feed method compared to other feed techniques has been proposed for 1.8 GHz applications. The designed and simulated CSPA is a rotary version of an initially designed rectangular planar patch antenna (RPPA). The RPPA is mounted on a cylindrical surface with radius (r) 10 mm which is an increased curvature for better -10 dB S-parameter (S 11 ), impedance band width (BW), voltage standing wave ratio (VSWR), radiation pattern, and gain. The copper radiating patch has been conformed on the surface of the grounded flexible polyimide substrate with relative permittivity (ε r ) 3.5 and thickness (h) 1.6 mm at normalized input impedance of 50 Ω. Results for the RPPA and the proposed CSPA have been compared with existing designs in terms of antenna size, resonant frequency (f r ), return loss (S 11 ), and gain while taking cognizance of the feeding techniques. The S 11 , BW, VSWR, and gain are-12.784 dB, 28 MHz, 1.8, and 4.81 dBi respectively for the rectangular planar patch antenna and -35.571 dB, 66 MHz, 1.5, and 3.74 dBi, respectively for the cylindrical surrounding patch antenna.
This document presents the design and optimization of a dual-frequency microstrip patch antenna using IE3D simulation software. A rectangular patch with two slots is used to create a second resonant TM0δ mode above the fundamental TM01 mode. IE3D's Fast EM and Powell optimizers are employed to optimize the geometric parameters and achieve maximum return losses of -36.5 dB at 7 GHz and -15 dB at 7.59 GHz with a 10 dB bandwidth. Simulation results for return loss, VSWR, and radiation patterns are provided and compared for the theoretical, Powell, and Fast EM optimized designs. The Fast EM optimization achieved the best performance and dual-band operation of the slotted microstrip patch antenna.
IRJET-Miniaturized Wide Bandwidth MIMO Dielectric Resonator Antenna using Def...IRJET Journal
This document presents a miniaturized wide bandwidth multiple-input multiple-output (MIMO) dielectric resonator antenna (DRA) using a defective ground structure for ultra-wideband applications. The antenna is designed to operate at 6.9 GHz and achieves an ultra-wide bandwidth of 4.692 GHz from 5.92 to 10.62 GHz without interfering with wireless local area network frequencies. Three designs are analyzed and the optimized design uses two DRAs made of Rogers RO4350 substrate with a dimension of 29x29x2.295 mm3. A stub is placed between the DRAs to provide isolation and reduce mutual coupling. The defective ground structure enhances the bandwidth. Simulation results show the optimized design meets requirements
This document summarizes the design and study of a compact and wideband microstrip U-slot patch antenna for Wi-Max applications. The antenna was designed to operate in the 5.25GHz Wi-Max band with very low return loss. Design formulas are provided to calculate the dimensions of the rectangular microstrip patch antenna. Simulation results show the return loss is below -30dB from 5.15GHz to 5.85GHz, meeting the bandwidth requirements. The proposed antenna design achieves wideband operation using a 3-layer substrate with total thickness of 1.6mm.
Packaging Technique for Gain Improvement of Multi resonance CPW-fed Antenna f...IJECEIAES
A suitable technique for gain improvement of multi-resonance CPW-fed antenna for satellite application at Ku-, K- and Ka-bands for user terminals is presented in this paper. New concept of stacking numerous layers with different dielectric material has been also presented. The conventional antenna design consists of a CPW-fed patch antenna with modified CPW elements printed on Rogers TMM4 substrate. In order to improve the antenna performance in term of gain and bandwidth, we propose two different configurations. The first one consists of designing a stacked structure by adding on the top of the single antenna an additional layer with parasitic elements. The dielectric added consists in Rogers RO3010 substrate with a high permittivity of 10.2. The proposed antenna is formed by two layers separated by an air gap; this new configuration provides major reduction on antenna beam width and allows gain enhancement. The second one implement the design of 2×1 and 4×1 series feed antenna arrays based on the conventional CPW-fed antenna. These array configurations are used to achieve higher gain in comparison with stacked solution. Finally we combined both techniques yielding the stacked 4×1 series feed antenna array. Fabricated CPW-fed antenna and the achieved results demonstrate the performance of presented techniques for gain improvements.
IRJET - Co-Axial Fed Tri-Slot Antenna for Triple-Band ApplicationIRJET Journal
This document describes the simulation and design of a coaxial fed tri-band microstrip patch antenna for wireless communication applications. The antenna is designed to operate in three bands: 2.28-2.35 GHz, 4.05-4.11 GHz, and 5.8-5.9 GHz. Rectangular slots are introduced on the patch to achieve the triple band performance. The dimensions of the slots and ground plane as well as the feed position are optimized using HFSS simulator. Simulation results show return losses less than -25 dB across the three bands and VSWR less than 2, indicating good impedance matching between the feed line and patch. Radiation patterns and efficiencies over 95% are obtained at the center frequencies
This document analyzes how increasing the surface area of a microstrip patch antenna affects its bandwidth. It begins by designing a basic rectangular microstrip patch antenna and simulating it to obtain a bandwidth of 1.4 GHz. Notches and slots are then added to the patch to increase its surface area. A dual H-shaped patch antenna with a H-shaped skeleton yields a bandwidth of 3.4 GHz and gain of 5 dB. Replacing the skeleton with dual U-slots results in a bandwidth of 3.5 GHz between 5.5-9 GHz and increased gain. In conclusion, increasing the patch's surface area through modifications like slots and notches can significantly improve the antenna's bandwidth.
This document summarizes the design and simulation of a dual-band Y-shaped printed antenna for satellite communication. A conventional microstrip patch antenna was first designed with a resonant frequency of 9.8 GHz. A Y-shaped slot was then introduced to the patch, reducing the resonant frequency to 6.23 GHz and 9.56 GHz. The simulated slotted antenna achieved a size reduction of 52.02% compared to the conventional design, with gains of 4.69 dBi at 6.23 GHz and 4.18 dBi at 9.56 GHz. Radiation patterns for both frequencies showed 3dB beamwidths between 166-170 degrees. The dual-band slotted antenna design demonstrates potential for C-band and X
Design of wide band slotted microstrip patch antenna with defective ground st...IJECEIAES
This paper proposes a microstrip patch antenna (MSPA) in the Ku band for satellite applications. The antenna is small in size with dimensions of about 40 mm×48 mm×1.59 mm and is fed with a coaxial cable of 50 Ω impedance. The proposed antenna has a wide bandwidth of 3.03 GHz ranging from 12.8 GHz to 15.8 GHz. To realize the characteristics of wideband the techniques of defective ground structure (DGS) and etching slots on the radiating element are adopted. The antenna is modeled on the FR4 substrate. A basic circular patch is selected for the design of a dual-frequency operation and in the next step DGS is introduced into the basic antenna and enhanced bandwidth is achieved at both the frequencies. To attain wider bandwidth two slots are etched on the radiating element of which one is a square ring slot and the second one is a circular ring slot. The novelty of the proposed antenna is a miniaturized design and unique response within the Ku band region which is applicable for wireless UWB applications with VSWR <2 and an average gain of 3.6 dB.
Gain enhancement of microstrip patch antenna using artificial magnetic conductorjournalBEEI
The paper presents an artificial magnetic conductor (AMC) structure to enhance the gain of the double microstrip patch antenna. By placing this kind of metamaterial in between the two Rogers RT5880 substrates, the antenna achieved lots of improvement especially in terms of size miniaturization, bandwidth, return loss, gain and efficiency. The antenna is intended to operate at 16 GHz where the prospect fifth generation (5G) spectrum might be located. Integration of AMC structure into the proposed antenna helps to improve nearly 16.3% of gain and almost 23.6% of size reduction.
Multiband antenna using stacked series array for Ka-Band applicationjournalBEEI
In this paper, a multiband stack series array antenna is designed in order to attain solutions for the future 28 GHz Ka-band application. Double layer substrate Technology is utilized to accomplish multiple resonant frequencies with higher data transfer capacities due to high bandwidth. The designed antenna is dependent on twofold layer consisting patches and resonators in different layers stacked together. The designed multiband antennas can resonate at single band of
(28 GHz), dual band of (28 and 30 GHz) and triple band of (24.18, 26 and 28.453). The results achieved in the simulation are later fabricated and tested. The test result illustrates that the antennas have wide bandwidth, high gain and even higher efficiencies. All the proposed antenna configurations have demonstrated a decent possibility for 5G millimeter wave (mmwave) application.
Different Multilayer Substrate Approaches to Improve Array Antenna Characteri...TELKOMNIKA JOURNAL
The aim of this paper is to investigate deeply in multi-layer substrate technique as a way of improving the characteristics of patch array antenna for electronic scanning radar application. The basic array antenna consists of 8 patches mounted on a FR-4 substrate and operating at 3 GHz frequency. The feeding technique is microstrip technology. This structure has some disadvantages as a poor gain and a narrow bandwidth. In fact, the obtained gain value does not exceed 7 dB which could be explained by the lossy nature of the FR4 substrate. On the other side, the narrow bandwidth is caused by the microstrip limitations. For this reason, the technique of multi-layer substrate is proposed in this paper. Many approaches are investigated and the distance between the layers is studied. The design and simulations of each approach are performed under the tool Advanced Design System of Keysight Company. A comparison between simulation results of all approaches including simulation results of the basic array antenna will be analyzed.
Simulation and analysis of slot coupled patch antennaiaemedu
The document discusses the simulation and analysis of a slot-coupled patch antenna at different frequencies using HFSS software. It describes the structure of the antenna, which consists of a rectangular patch separated from the ground plane by an air gap and dielectric material. The paper simulates the antenna at 2.25 GHz, 3.25 GHz, and 4.5 GHz. It analyzes the return loss and radiation patterns at each frequency. The results show that bandwidth increases at higher frequencies but radiation patterns degrade, indicating a tradeoff between bandwidth and frequency of operation.
Simulation and analysis of slot coupled patch antennaiaemedu
The document summarizes research on simulating and analyzing a slot-coupled patch antenna at different frequencies using HFSS software. It describes the structure of the antenna, which consists of a rectangular patch separated from the ground plane by an air gap and dielectric material. The antenna is fed by two slots on the ground plane. Simulation results showed that bandwidth increases at higher frequencies but radiation patterns deteriorate. There is thus a tradeoff between operating frequency, bandwidth, and radiation efficiency. The design was able to achieve bandwidth increases up to 80 MHz at 4.5 GHz but radiation patterns worsened compared to lower frequencies.
The document investigates the effect of dielectric superstrates on the bandwidth, gain, and resonant frequency of a U-slot microstrip patch antenna. It is found that placing a superstrate directly on the patch degrades performance by lowering the resonant frequency, decreasing bandwidth, and reducing gain. However, positioning the superstrate at an optimal height above the patch (Hopt) improves performance such that the gain and bandwidth approach levels achieved without a superstrate. Both simulated and experimental results show that superstrate height is a key parameter, and performance degradation can be mitigated by setting the height to Hopt.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
New Miniature Planar Microstrip Antenna Using DGS for ISM ApplicationsTELKOMNIKA JOURNAL
The aim of this paper is to use defected ground structures (DGS) in order to miniaturize a
microstrip patch antenna. The DGS structure is integrated in the ground plane to improve the performance
of the planar antenna, and shifted the resonance frequency from 5.8 GHz to 2.5 GHz, with a
miniaturization up to 83%. The antenna is designed, optimized, and miniaturized by using the CST MWstudio,
mounted on an FR-4 substrate having a dielectric constant 4.4, a loss tangent tan (ɸ)=0.025,
thickness of 1.6 mm with the whole area of 34X34 mm2.The proposed antenna is suitable for ISM
(Industrial, Scientific and Medical) applications at 2.5 GHz with S11 ≤(-10) dB. The antenna is fed by
50ohm input impedance and it has good performances in terms of matching input impedance and radiation
pattern. The proposed antenna was fabricated and tested.Simulation and measurement results are in good
agreement.
Microstrip patch antenna with defected ground structure for biomedical applic...journalBEEI
1. The document describes a defected ground structure-based microstrip patch antenna proposed for narrowband biomedical applications.
2. The antenna resonates at 2.45 GHz with a return loss of -30 dB and a bandwidth of 20 MHz, covering channel 9 of the ISM band.
3. The use of defected ground structure increases the antenna gain to 7.04 dBi and efficiency by 17.63%, with better radiation patterns and current distribution compared to the antenna without defected ground structure.
The document describes the design and simulation of a dual-band microstrip patch antenna with a defected ground structure for STM-1 and cellular applications at 4.9 GHz and 7.6 GHz. A rectangular patch antenna was designed on a dielectric substrate above a ground plane. Two slots were etched into the ground plane to create a defected ground structure. Simulation results showed the antenna achieved return losses of -12.75 dB and -13.01 dB at 4.9 GHz and 7.6 GHz respectively, meeting the design requirements. Parameters like slot width and feed length were optimized to improve impedance matching and bandwidth. The antenna design demonstrates a technique for dual-band operation using a defected ground structure.
A novel multi-resonant and wideband fractal antenna for telecommunication ap...IJECEIAES
This letter presents the design, simulation, and measurement of a novel multiband fractal circular antenna for wireless applications. In the antenna design, we used a circular antenna where we took a ring. Then, in the first iteration, we added a new ring divided into two of the same size. For the second iteration, we added a ring of the same size after dividing it into two halves. In the third iteration, we added the third ring of the same size after dividing it into four. Due to the resonator defection, we were able to reduce the size of the starting antenna from 60×70×2 mm3 to 50×50×1.6 mm3 , to get the frequency of 2.48 GHz, and we generated new bandwidths with a high gain that reaches 5.02 dB. The proposed antenna radiation characteristics, such as the impedance matching, the gain, the radiation pattern, and the surface current distribution are presented and discussed. We find that the simulated and measured results are in acceptable agreement and affirm the good performance of the proposed antenna. The results obtained affirm that the proposed fractal antenna is a better candidate for integration into wireless communication circuits.
Modified e-slotted patch antenna for WLAN/Wi-Max satellite applicationsTELKOMNIKA JOURNAL
A low profile modified e-slotted microstrip antenna is proposed for multiple wireless communication applications. The performance of antenna is measured in terms of return loss, current distribution. The effect of variation of height of substrate on antenna impedance bandwidth is also studied. The antenna with overall size 30×50×.8m.m.3 resonates at eight frequencies which covers some important applications like GPS, wireless local area network (WLAN), worldwide interoperability for microwave access (WiMax), Satellite communication etc. The proposed antenna structure offers great advantages due to compact size, simple structure and multiple applications. The multi band antenna was designed and optimized using ansoft HFSS v13 simulator. The simulated result is good agreement with measured result.
Dual-band aperture coupled antenna with harmonic suppression capabilityTELKOMNIKA JOURNAL
The paper presents an aperture-coupled dual-band linearly-polarized antenna with harmonic suppression capability, operating at frequency 2.45 GHz and 5.00 GHz. In purpose of improving the directivity of antenna at the operating frequency of 2.45 GHz and 5.00 GHz, a modified inverted π-shaped slot-etched patch on the lower layer of the stacked antenna is introduced alongside the 50 Ω feed line. The harmonic suppression capability is achieved by the introduction of U-slot and asymmetrical left-right-handed stub at the transmission feed line, suppressing unwanted harmonic signals from 6.00 GHz up to 10.00 GHz. The final design of the antenna has produced very good reflection coefficient of -18.87 dB at 2.45 GHz and -19.57 dB at 5.00 GHz with third and higher order harmonic suppression up to -4 dB.
This document summarizes a research paper that designed and simulated a microstrip patch antenna with an H-shaped defected ground structure (DGS) for bandwidth improvement and miniaturization. Key findings include:
1) A conventional square patch antenna was designed to resonate at 2.36GHz.
2) An H-shaped DGS was embedded in the ground plane of the antenna to perturb the current distribution and affect the input impedance.
3) Simulations showed the DGS antennas resonated at lower frequencies than the conventional antenna, with impedance bandwidth improvements up to 500MHz and size reductions up to 65.51%.
4) Radiation patterns of the DGS antennas remained nearly omn
In this paper microstrip patch antenna is designed for 2.4GHz frequency. For the antenna miniaturization and bandwidth improvement H-shaped DGS on microstrip patch antenna (MSA) is used. The design of DGS has been analyzed for different dimensions of H-slot and achieved optimized dimensions.The simulation process has been done through Finite Element Machine (FEM) based software High Frequency Structure Simulator ( HFSS) software. The properties of antenna such as reflection co-efficient, bandwidth and gain are determined and compared with the properties of single element square patch antenna.Further proposed antennas performance is studied for different size of defect on the same patch antenna. Proposed antenna finds its application in wireless LAN protocols such as Bluetooth, IEEE 802.11 and in 2.4GHz ISM Band.
This document describes the design and simulation of a stacked microstrip patch antenna with different shaped patches to improve bandwidth. Two configurations are proposed with an E-shaped patch on bottom and U-shaped slotted patch on top, and vice versa. The E-shaped and U-shaped patches are simulated individually then combined in a stacked configuration. Simulation results in HFSS show the configuration with E-shaped patch on top and U-shaped patch on bottom provides dual band operation with improved bandwidth of 1.3 GHz at 5.06 GHz and 1.1 GHz at 7 GHz. The antenna achieves a gain of 7.5 dB at 5 GHz and 6 dB at 7 GHz with a VSWR of less than 2.
Design and Optimization of a High Gain Multiband Patch Antenna for Millimeter...IJECEIAES
The document describes the design and optimization of a quad-band patch antenna for millimeter wave applications between 27-51 GHz. The proposed antenna incorporates two symmetric "U" shaped slots and a central "I" shaped slot etched into the ground plane of a circular patch antenna. Simulation results show that the antenna resonates at four frequencies in the Ka, V and W bands. Tuning the dimensions and positions of the slots can shift the resonant frequencies. The optimized antenna design achieves high gain across the operating bands making it suitable for millimeter wave applications.
Wideband frequency reconfigurable metamaterial antenna design with double H s...journalBEEI
This paper presents the design of wideband frequency reconfigurable metamaterial antenna with double H slots. The design is based on the idea of composite right/left-handed transmission line (CRLH-TL) technique. Bandwidth enhancement was achieved by utilizing series left-handed capacitor CL transmission line parameter. The design has several outstanding advantages which include efficient bandwidth to cover many lower Application bands with multi frequency operation characteristics. A comprehensive analysis and simulation were done by using computer simulation technology (CST) software to determine the performance and efficiency of the proposed antenna. From the result obtained, the antenna aquired bandwidth range which covered (2.3-5.2) GHz which is equivalent to 77% fractional bandwidth. The wideband antenna was reconfigured by using frequency reconfiguration technique. From the reconfiguration results, the antenna can be switch from wideband to two single bands which resonate at 2.4 GHz and 4.2 GHz and to dual band which resonate at 2.4 GHz and 4.2 GHz. The realized peak gain at 2.4 GHz is 2.28 dBi and 2.58 dBi for E and H field respectively. The maximum efficiency of 96% was obtained. The antenna can be use for WLAN, proposed lower 5G band and cognitive radio system for frequency sencing.
IRJET - Multiband Concentric Ring Circular Microstrip Patch AntennaIRJET Journal
This document describes a multiband circular microstrip patch antenna with concentric rings. The antenna is designed to operate in the X-band frequency of 10 GHz but provides high gain and bandwidth across other frequency bands as well. The antenna structure consists of a circular patch surrounded by concentric circular strips connected to each other. Simulation results show the antenna resonates at 6 frequencies between 7.6-12 GHz. The maximum gain is approximately 7.5 dBi and maximum bandwidth is around 500 MHz. The antenna design provides multiband capability with high gain using a simple, easy-to-fabricate structure.
Microstrip Rectangular Monopole Antennas with Defected Ground for UWB Applica...IJECEIAES
This paper presents the design of new compact antennas for ultra wide band applications. Each antenna consists of a rectangular patch fed by 50Ω microstrip transmission line and the ground element is a defected ground structure (DGS). The aim of this study is to improve the bandwidth of these antennas by using DGS and the modification geometry of rectangular structure, which gives new compact antennas for UWB applications. The input impedance bandwidth of the antennas with S11<-10dB is more than 10GHz, from 3GHz to more than 14 GHz. The proposed antennas are investigated and optimized by using CST microwave studio, they are validated by using another electromagnetic solver Ansoft HFSS. The measured parameters present good agreement with simulation. The final antenna structures offer excellent performances for UWB system.
Similar to Implementation of double-layer loaded on octagon microstrip yagi antenna (20)
Square transposition: an approach to the transposition process in block cipherjournalBEEI
The transposition process is needed in cryptography to create a diffusion effect on data encryption standard (DES) and advanced encryption standard (AES) algorithms as standard information security algorithms by the National Institute of Standards and Technology. The problem with DES and AES algorithms is that their transposition index values form patterns and do not form random values. This condition will certainly make it easier for a cryptanalyst to look for a relationship between ciphertexts because some processes are predictable. This research designs a transposition algorithm called square transposition. Each process uses square 8 × 8 as a place to insert and retrieve 64-bits. The determination of the pairing of the input scheme and the retrieval scheme that have unequal flow is an important factor in producing a good transposition. The square transposition can generate random and non-pattern indices so that transposition can be done better than DES and AES.
Hyper-parameter optimization of convolutional neural network based on particl...journalBEEI
The document proposes using a particle swarm optimization (PSO) algorithm to optimize the hyperparameters of a convolutional neural network (CNN) for image classification. The PSO algorithm is used to find optimal values for CNN hyperparameters like the number and size of convolutional filters. In experiments on the MNIST handwritten digit dataset, the optimized CNN achieved a testing error rate of 0.87%, which is competitive with state-of-the-art models. The proposed approach finds optimized CNN architectures automatically without requiring manual design or encoding strategies during training.
Supervised machine learning based liver disease prediction approach with LASS...journalBEEI
In this contemporary era, the uses of machine learning techniques are increasing rapidly in the field of medical science for detecting various diseases such as liver disease (LD). Around the globe, a large number of people die because of this deadly disease. By diagnosing the disease in a primary stage, early treatment can be helpful to cure the patient. In this research paper, a method is proposed to diagnose the LD using supervised machine learning classification algorithms, namely logistic regression, decision tree, random forest, AdaBoost, KNN, linear discriminant analysis, gradient boosting and support vector machine (SVM). We also deployed a least absolute shrinkage and selection operator (LASSO) feature selection technique on our taken dataset to suggest the most highly correlated attributes of LD. The predictions with 10 fold cross-validation (CV) made by the algorithms are tested in terms of accuracy, sensitivity, precision and f1-score values to forecast the disease. It is observed that the decision tree algorithm has the best performance score where accuracy, precision, sensitivity and f1-score values are 94.295%, 92%, 99% and 96% respectively with the inclusion of LASSO. Furthermore, a comparison with recent studies is shown to prove the significance of the proposed system.
A secure and energy saving protocol for wireless sensor networksjournalBEEI
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The calculation of the field of an antenna located near the human headjournalBEEI
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Design of a dual-band antenna for energy harvesting applicationjournalBEEI
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Key performance requirement of future next wireless networks (6G)journalBEEI
The document provides an overview of the key performance indicators (KPIs) for 6G wireless networks compared to 5G networks. Some of the major KPIs discussed for 6G include: achieving data rates of up to 1 Tbps and individual user data rates up to 100 Gbps; reducing latency below 10 milliseconds; supporting up to 10 million connected devices per square kilometer; improving spectral efficiency by up to 100 times through technologies like terahertz communications and smart surfaces; and achieving an energy efficiency of 1 pico-joule per bit transmitted through techniques like wireless power transmission and energy harvesting. The document outlines how 6G aims to integrate terrestrial, aerial and maritime communications into a single network to provide ubiquitous connectivity with higher
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Parking detection system using background subtraction and HSV color segmentationjournalBEEI
Manual system vehicle parking makes finding vacant parking lots difficult, so it has to check directly to the vacant space. If many people do parking, then the time needed for it is very much or requires many people to handle it. This research develops a real-time parking system to detect parking. The system is designed using the HSV color segmentation method in determining the background image. In addition, the detection process uses the background subtraction method. Applying these two methods requires image preprocessing using several methods such as grayscaling, blurring (low-pass filter). In addition, it is followed by a thresholding and filtering process to get the best image in the detection process. In the process, there is a determination of the ROI to determine the focus area of the object identified as empty parking. The parking detection process produces the best average accuracy of 95.76%. The minimum threshold value of 255 pixels is 0.4. This value is the best value from 33 test data in several criteria, such as the time of capture, composition and color of the vehicle, the shape of the shadow of the object’s environment, and the intensity of light. This parking detection system can be implemented in real-time to determine the position of an empty place.
Quality of service performances of video and voice transmission in universal ...journalBEEI
The universal mobile telecommunications system (UMTS) has distinct benefits in that it supports a wide range of quality of service (QoS) criteria that users require in order to fulfill their requirements. The transmission of video and audio in real-time applications places a high demand on the cellular network, therefore QoS is a major problem in these applications. The ability to provide QoS in the UMTS backbone network necessitates an active QoS mechanism in order to maintain the necessary level of convenience on UMTS networks. For UMTS networks, investigation models for end-to-end QoS, total transmitted and received data, packet loss, and throughput providing techniques are run and assessed and the simulation results are examined. According to the results, appropriate QoS adaption allows for specific voice and video transmission. Finally, by analyzing existing QoS parameters, the QoS performance of 4G/UMTS networks may be improved.
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Social media management system project report.pdfKamal Acharya
The project "Social Media Platform in Object-Oriented Modeling" aims to design
and model a robust and scalable social media platform using object-oriented
modeling principles. In the age of digital communication, social media platforms
have become indispensable for connecting people, sharing content, and fostering
online communities. However, their complex nature requires meticulous planning
and organization.This project addresses the challenge of creating a feature-rich and
user-friendly social media platform by applying key object-oriented modeling
concepts. It entails the identification and definition of essential objects such as
"User," "Post," "Comment," and "Notification," each encapsulating specific
attributes and behaviors. Relationships between these objects, such as friendships,
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among objects, and polymorphism for flexible content handling. Use case diagrams
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during critical scenarios. Class diagrams provide an overarching view of the system's
architecture, including classes, attributes, and methods .By undertaking this project,
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Conservation of Taksar through Economic RegenerationPriyankaKarn3
This was our 9th Sem Design Studio Project, introduced as Conservation of Taksar Bazar, Bhojpur, an ancient city famous for Taksar- Making Coins. Taksar Bazaar has a civilization of Newars shifted from Patan, with huge socio-economic and cultural significance having a settlement of about 300 years. But in the present scenario, Taksar Bazar has lost its charm and importance, due to various reasons like, migration, unemployment, shift of economic activities to Bhojpur and many more. The scenario was so pityful that when we went to make inventories, take survey and study the site, the people and the context, we barely found any youth of our age! Many houses were vacant, the earthquake devasted and ruined heritages.
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Response & Safe AI at Summer School of AI at IIITHIIIT Hyderabad
Talk covering Guardrails , Jailbreak, What is an alignment problem? RLHF, EU AI Act, Machine & Graph unlearning, Bias, Inconsistency, Probing, Interpretability, Bias
How to Manage Internal Notes in Odoo 17 POSCeline George
In this slide, we'll explore how to leverage internal notes within Odoo 17 POS to enhance communication and streamline operations. Internal notes provide a platform for staff to exchange crucial information regarding orders, customers, or specific tasks, all while remaining invisible to the customer. This fosters improved collaboration and ensures everyone on the team is on the same page.
Encontro anual da comunidade Splunk, onde discutimos todas as novidades apresentadas na conferência anual da Spunk, a .conf24 realizada em junho deste ano em Las Vegas.
Neste vídeo, trago os pontos chave do encontro, como:
- AI Assistant para uso junto com a SPL
- SPL2 para uso em Data Pipelines
- Ingest Processor
- Enterprise Security 8.0 (Maior atualização deste seu release)
- Federated Analytics
- Integração com Cisco XDR e Cisto Talos
- E muito mais.
Deixo ainda, alguns links com relatórios e conteúdo interessantes que podem ajudar no esclarecimento dos produtos e funções.
https://www.splunk.com/en_us/campaigns/the-hidden-costs-of-downtime.html
https://www.splunk.com/en_us/pdfs/gated/ebooks/building-a-leading-observability-practice.pdf
https://www.splunk.com/en_us/pdfs/gated/ebooks/building-a-modern-security-program.pdf
Nosso grupo oficial da Splunk:
https://usergroups.splunk.com/sao-paulo-splunk-user-group/
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Implementation of double-layer loaded on octagon microstrip yagi antenna
1. Bulletin of Electrical Engineering and Informatics
Vol. 10, No. 6, December 2021, pp. 3289~3296
ISSN: 2302-9285, DOI: 10.11591/eei.v10i6.3193 3289
Journal homepage: http://beei.org
Implementation of double-layer loaded on octagon microstrip
yagi antenna
Kamelia Quzwain1
, Alyani Ismail2
, Yudiansyah3
, Nadia Media Rizka4
,
Aisyah Novfitri5
, Lia Hafiza6
1,3,4,5,6
Department of Telecommunication Engineering, Institut Teknologi Telkom Jakarta, Indonesia
2
Department of Computer and Communication Systems Engineering, Universiti Putra Malaysia, Malaysia
Article Info ABSTRACT
Article history:
Received Jul 31, 2021
Revised Sep 23, 2021
Accepted Oct 29, 2021
A double-layer loaded on the octagon microstrip yagi antenna (OMYA) at 5.8
GHz industrial, scientific and medical (ISM) Band is investigated in this
paper. The double-layer consist of two double positive (DPS) substrates. The
OMYA is overlaid with a double-layer configuration were simulated,
fabricated and measured. A good agreement was observed between the
computed and measured results of the gain for this antenna. According to
comparison results, it shows that 2.5 dB improvement of the OMYA gain can
be obtained by applying the double-layer on the top of the OMYA.
Meanwhile, the bandwidth of the measured OMYA with the double-layer is
14.6%. It indicates that the double-layer can be used to increase the OMYA
performance in term of gain and bandwidth.
Keywords:
ISM band
Microstrip antenna
Multilayer
Photonic crystal
Yagi antenna This is an open access article under the CC BY-SA license.
Corresponding Author:
Kamelia Quzwain
Department of Telecommunication Engineering
Institut Teknologi Telkom Jakarta
Daan Mogot KM.11, Cengkareng, West Jakarta 11710, Indonesia
Email: kamelia@ittelkom-jkt.ac.id
1. INTRODUCTION
Frequency of 5.8 GHz is one of unlicensed frequencies which is used in low rate applications, for
instance, sensor and radar [1]-[3]. Antennas play a vital role in wireless communication system. Microstrip
patch antennas (MPAs) have some attractive advantages, such as easy fabrication, simplicity in design and
lightweight. However, MPAs are associated with low gain [4]-[7]. Multilayer structure concept can be used
to increase the gain of MPAs [8]-[11]. In addition, Yagi-Uda concept can be employed to tackle this
limitation [12]. Several MPA-based Yagi-Uda concept have been introduced in [13]-[15].
In 2007, Dejean et al [13] reported a high gain microstrip Yagi antenna in order to improve the
performance of the first microstrip Yagi antenna. The gain of their antenna is 10.7 dB with a size of 112 x
112 mm2
. Octagon microstip yagi antenna (OMYA) was introduced by Quzwain et al in [14]. Four octagon
patches were successfully applied as driven elements to increase the performance in terms of bandwidth and
gain without increasing the size of the antenna. This antenna is able to produce a gain of 11 dB with the
surface size of 70 mm x 75 mm. As reported in literature [15], microstrip Yagi-Uda antenna can be
constructed in a stacked-multilayer in order to minimize the size of the antenna. A gain of about 11 dB can be
achieved through this design.
On the other side, numerous researchers in [16]-[18] were attracted to increase the gain of MPA by
placing double positive (DPS) substrate above the MPA as a superstrate layer. An extra gain can be achieved
by choosing the thicknesses of the DPS substrate and the superstrate layers properly. An interesting method
2. ISSN: 2302-9285
Bulletin of Electr Eng & Inf, Vol. 10, No. 6, December 2021 : 3289 – 3296
3290
to obtain more gain was introduced in [19] where the octagon fractal microstrip yagi antenna (OFMYA) is
overlaid with a combined double negative (DNG) and DPS substrates as superstrate layer. To date, no
previous experimental study has provided information on OMYA using double-layer. This paper introduces
the OMYA using a doble-layer in order to improve the OMYA performance. Data for this investigations
were collected based on simulation and experimental results. The paper is structured as; section 2 begins by
giving an explanation of the proposed antenna design, the third section is concerned with the imulation and
measurement results of the proposed antenna, the final section summarises the main findings of this research.
2. ANTENNA DESIGN CONFIGURATION
This Section explains the configuration of the proposed antenna design. The proposed antenna here
is formed by one OMYA and two covers which are placed above the OMYA. The first stage is to consider
the specifications of the proposed antenna based on its application as tabulated in Table 1.
Table 1. Antenna design parameters
Antenna Parameters Values
Frequency Range 5.725 GHz–5.875 GHz
Centre Frequency 5.8 GHz
Bandwidth (BW) 150 MHz
VSWR ≤ 2.0
Radiation Pattern Broadside Directional
The proposed antenna in this paper comprises two double positive (DPS) substrates in which acts as
superstrate layer. Figure 1 shows the OMYA structure which was first demonstrated experimentally by
Quzwain et al [14]. The antenna was designed by using the same design rules as used in the conventional
microstrip Yagi Uda antenna which is composed of a reflector element, a driven element and some director
elements. Detailed explanations of the OMYA design can be found in [14]. The OMYA was fabricated on
rogers 5880 with thickness of 1.575 mm. The antenna consists of two reflector elements (Rt & Rb), one driven
element (DR), two bottom director elements (D1b & D2b) and two top director elements (D1t & D2t).
Side View
X
Z
Y
Ground Plane
Substrate (εr)
Front View
X
Y
Z
D1b
D1t D2t
D2b
Rt
Substrate (εr)
S
g
Mt
Mt
Wd
h
Rb
Rb
D1b D2b
DR
DR
Wd
WR
Wf
y0
Lf
LP
Wd
WP SD
Figure 1. The OMYA geometry in [14]
A periodic structure of two or more DPS materials can be used to increase the gain. This
arrangement is also called one-dimensional photonic crystal (1-D PCs) [20], [21]. It is the simplest structure
among the three types of photonic crystal (PCs) in which comprises more than one DPS Material which is
separated by air gap (h3) in periodic arrangement of z-axis as illustrated in Figure 2. This concept involves
the addition of two high dielectric permittivity substrates on the top of the MPA [22], [23]. As shown in
Figure 2, two additional substrates with dielectric permittivity of εr2 and thickness of t are placed above the
3. Bulletin of Electr Eng & Inf ISSN: 2302-9285
Implementation of double-layer loaded on octagon microstrip yagi antenna (Kamelia Quzwain)
3291
antenna at height of h2. The separation distance between two superstrate layers is h3. Multiple superstrates
method can be used to produce a narrow-beam radiation pattern when [24]:
𝑛0ℎ2
𝜆0
√1 =
𝑠𝑖𝑛2𝜃𝑝
(𝑛0)2 = 0.05 (1)
and
𝑛1𝑡
𝜆0
√1 =
𝑠𝑖𝑛2𝜃𝑝
(𝑛1)2 = 0.25 (2)
Where θP is beam angle and the refraction of air (n0) equals to one and the refraction of superstrate (n1) can
be determined as.
𝑛1 = √ε1μ1 (3)
Two Arlon AD1000 materials with εr of 10.2 and thickness of 2.5 mm were used as DPS layer. A
number of optimizations was done through CST Microwave Studio software in order to achieve the best
result for gain based on h2 and h3 variation. The simulated gain results was observed in order to explore the
relationship between the gain and the air gaps (h2 and h3).
Figure 2. The designed OMYA with double DPS layer geometry
3. RESULTS AND DISCUSSION
In order to achieve a high gain and wide bandwidth, the OMYA was calculated and optimized by
Quzwain et al in [14]. They explained that the side length of octagon-shaped (Wd) and gap between parasitic
elements (g) give influence on gain and bandwidth of the OMYA. The first observation is the influence of
placing single layer above the OMYA in order to examine the effect of the first air gap thickness (h2) and
superstrate thickness (hss) on gain. In this stage, the single-superstrate was moved vertically to the top with
different superstrate thickness. The variation of the gain with respect to the first air gap thickness (h2) for
different superstrate thickness (hss) is shown in Figure 3. In this simulation result, it shows that a maximum
gain of 12.42 dB can be obtained through this design where the optimum hss for the maximum gain is 2.54
mm at h2 of 31 mm.
It is also clearly seen that the gain moves downward as the hss value decreases. The graph also
shows that the gain rise slightly between h2 of 25 mm and h2 of 31 mm and then decreases slightly. From this
simulation result, it can be summarized that the gain of the OMYA can be enhanced up to 1.22 dB by adding
single-layer configuration above the OMYA. Additionally, it proves that a thick superstrate is capable of
4. ISSN: 2302-9285
Bulletin of Electr Eng & Inf, Vol. 10, No. 6, December 2021 : 3289 – 3296
3292
increasing the gain. Placing double-layer above the OMYA is the final stage in antenna design. In this stage,
two crucial factors influencing the gain frequency characteristics; h2 and h3. In order to further investigate the
effect of h2 and h3 air gaps on the gain, this stage explores the gain variations with changing the h2 value for
different the h3 value and keeping dielectric permittivity of the second superstrate (εr-2SS) equals to the
dielectric permittivity of the first one (εr-1SS). Usually the superstrate is placed half-wavelength (λ0/2) above
the antenna [25] to enhance the gain. Therefore, the starting point of h2 and hSS from the radiating patch of the
OMYA is around 25 mm. Then, the first air gap height of h2 was optimized by varying the value of h2 in
order to achieve the maximum gain. On the other side, the thickness of second air gap (h3) was also
optimized by moving the position of the second superstrate in y-axis which is started at h3 of 1 mm.
Figure 3. Gain variation versus the first air gap thickness (h2) for different superstrate thickness (hss)
Figure 4 depicts the simulated results for this experiment. From this figure, it can be observed that
the gain values for h3 of 3 mm which are shown in black solid line are higher than other lines. A maximum
gain of 13.7 dB can be obtained at h2 of 27 mm, hence there is an extra gain of 1.28 dB after placing another
superstrate above the first superstrate which is separated by air gap. It indicates that the OMYA with double-
layer is able to enhance the gain up to 2.5 dB compared to the OMYA without double-layer. It means that
double superstrate concept can be used to enhance the gain of the OMYA due to the ability to focus the
radiated electromagnetic energy and increase the gain of the OMYA.
Figure 4. Gain variation with changing the first air gap height (h2) for different the second air gap height
(h3)
It can be noted that there is a limit on the values of h2 and h3. The gain will be suppressed if the h2
and h3 values become too large. As a result, the h2 and h3 values for the antenna in this research are 27 mm
and 3 mm, respectively. The simulated S11 of the OMYA with double DPS layer having h2 of 27 mm and h3
of 3 mm is plotted in Figure 5. This plot shows that the antenna works in a frequency band from 5.48 GHz to
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6.32 GHz with a center frequency of 5.8 GHz and a wide bandwidth of 840 MHz or 14.5% in fractional
bandwidth.
Figure 6 portrays the simulated radiation patterns 3-Dimensional of the optimized OMYA with
double-layer at 5.8 GHz. Through observing this figure, the OMYA with double-layer has capability to
achieve a maximum gain up to 13.7 dB with the main lobe direction occurs in in E-Plane of 16°. It is
interesting to note that the gain of the OMYA with double-layer is 2.5 dB higher compared to the OMYA
without double-layer in [14], thus it gives evidence that double-layer can be used to enhance the gain. Table 2
summarize the optimized parameters of the OMYA with double-layer.
Table 2. The optimized parameters
Antenna Parameters Dimension (mm)
Air gap (h2) 27
Air gap (h3) 3
Superstrate Thickness (hss) 2.5
Substrate Thickness (h) 1.575
Total height of the proposed antenna (Ht) 39
Total width of the proposed antenna (Wt) 70
Figure 5. The simulated S11 of the OMYA with double-layer Figure 6. The simulated radiation patterns of
OMYA with double-layer
The antenna prototype is shown in Figure 7. It can be seen that two high dielectric permittivity
substrates are placed on the top of the OMYA and fixed using 4 plastic spacers at its 4 corners with plastic
nuts. The two fabricated antennas was measured in order to validate the simulation models. An anechoic
chamber at UTHM EMC Center – Batu Pahat was used to conduct the radiation pattern and gain
measurements. Meanwhile, Anritsu 37347D vector network analyzer (VNA) was used to measure S11.
Figure 7. The prototype of the OMYA with double DPS layer
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Figure 8 plots the computed S11 of the proposed antenna in comparison with the measured S11 result
over frequency range from 4 GHz to 7 GHz. Black solid line corresponds to the measured S11 has value
below -10 dB in a frequency band from 5.45 GHz to 6.6 GHz, thus it has a fractional bandwidth of around
19.8% which is equal to a bandwidth of 1148 MHz. It is obviously seen that there is a discrepancy between
the simulated and measured S11 at upper frequency (fu) which the measured fu is shifted to 6.6 GHz. Hence, a
deviation of 980 MHz occurs at the upper frequency. It may be due to the amount of solder, the
environmental factors such as noise and temperature of the room during measurement. Overall, the measured
bandwidth of the fabricated antenna is wider than its simulated result by 35%.
Figure 8. The simulated and measured S11
The experimental results for the radiation patterns are plotted in Figure 9. Black solid and dotted
lines denote the measured and simulated radiation patterns, respectively. Figure 9 provides far field
directivity of the antenna. With respect to Figure 9 (a), it shows the E-Plane of the antenna prototype has
maximum radiation at an angle of about 10° from broadside direction. On the other side, Figure 9 (b) shows
the H-Plane of the proposed antenna. It can be observed that there is a small shift between the computed and
the experimental results which is caused by fabrication imperfections, for instance, inaccuracy in placing the
superstrate, etching process and connector soldering.
According to the measurement results, it was found that the antenna has a gain of 13 dB. It indicates
that a good agreement was achieved between the computed and measured results of the gain for this antenna,
although the measured gain is about 0.7 dB lower than the simulated gain. It can be well observed from the
results that the directive gain of the antenna can be enhanced by using double-layer with a proper choice of
air gap thicknesses of h2 and h3 due to double-layer concept is able to concentrate the radiated waves in a
small angle. However, it is obviously seen that there is a discrepancy between the simulated and measured
S11 and radiation patterns as shown in Figure 8 and Figure 9, respectively. It may be caused by fabrication
imperfections and the environmental factors such as noise and temperature of the room during measurement.
All the simulation and experimental results are summarized in Table 3.
(a) (b)
Figure 9. Far field directivity (a) E-field and (b) H-field
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Table 3. Comparison results of S11, BW, and gain
Antenna Parameters
Centre Freq.
(GHz)
BW
(MHz)
BW
(%)
S11
(dB)
Gain
(dB)
Simulated OMYA
without double-layer (OMYA)
5.8
812 14 -23 11.2
Simulated OMYA
with double-layer
850 14.6 -20.62 13.7
Fabricated OMYA
with double-layer
1148 19.8 -20 13
4. CONCLUSION
The OMYA is overlaid with double-layer was simulated, fabricated and measured in order to
explore the influence of the double-layer on the OMYA performance. According to the simulation and
measurement results, it shows that the double-layer is able to enhance the OMYA performance in term of
gain and BW. The simulation result shows that the maximum fractional bandwidth of the OMYA without
double-layer increased by 0.6% compared to the OMYA is overlaid with double-layer. One interesting
finding is the bandwidth of the measured OMYA prototype is considerably larger than the simulated design.
Therefore, it can be concluded that the bandwidth and gain of the OMYA can be increased by placing
double-layer above the OMYA.
ACKNOWLEDGEMENTS
The author would like to express their heartfelt gratitude to Ministry of Higher Education and
Indonesia Endowment Fund for Education (LPDP) for financing this research.
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