INTERNATIONAL JOURNAL OF MICROWAVE AND OPTICAL TECHNOLOGY

VOL. 16, NO. 2, MARCH 2021
A PUBLICATION OF THE
INTERNATIONAL ACADEMY OF MICROWAVE AND OPTICAL TECHNOLOGY (IAMOT)
Reno, NV 89511, U.S.A.
MARCH 2021 VOLUME 16 NUMBER 2 IJMOT ISSN: 1553-0396
Banmali S Rawat

Editor-In-Chief

MESSAGE FROM EDITOR-IN-CHIEF
MICROWAVE RELATED PAPERS
Manuscript Title:Hybrid Beamforming and DOA Algorithms for Smart Antenna System Deployed in 5G Mobile Network
Manuscript Id:IJMOT-2020-9-72016
Abstract:Smart antenna (SA) system has recently received an important interest for all the enhancement it will bring to 5G mobile network. This system of antennas includes a large number of techniques that attempt to improve the received signal and suppress all the interfering ones. Thus SA system increases the received signal to noise ratio (SNR) which in return reduces the bit error rate (BER) and improves the throughput. The data rate is also improved trough spatial multiplexing of more than one data stream simultaneously, this will also increase the capacity. The purpose of our article is to find the most appropriate beamforming technique and Direction of Arrival (DoA) algorithm, which can be widely used for the design of a smart antenna system deployed in 5G communication.
Authors:Lamiae Squali, Fatima Riouch, Hafid Tiyzi, Hanae Squali
Submitted On:23-09-2020
Pages:112-123
Action: [Full Paper] No. of Downloads: 98
Manuscript Title:Spectrum Sensing for Wireless Medical Telemetry Systems using a Modified Normalized Adaptive Algorithm
Manuscript Id:IJMOT-2020-10-102017
Abstract:In cognitive radios, the spectrum sensing method is used to detect primary user signals in frequency spectrum. In received signals, due to statistical covariance’s primary signal is present with noise. But this noise power is not fixed and varies due to random noise and interference occurred in the networks. This noise power may lead to noise uncertainty problems in energy detection performance. So, in this paper proposed a bias compensated normalized least mean square (BNLMS) algorithm which includes noise power used for adjusting the threshold, then noise power is adjusted at each sensing point of the licensed spectrum. By the proposed method noisy inputs are estimated and they are eliminated. Further stability is also analyzed by calculating mean deviation and mean square deviation analysis, then convergence and steady state error rate performance is seen for variable step size with stabilization. Then probability detection, false alarm probability is calculated to reduce sensing errors for improving energy detection performance by avoiding noise uncertainty problems, we get a better probability of detection for different SNR values when compared to other algorithms and this concept is used in remote health care monitoring for avoiding noise interferences occurred with wireless communications.
Authors:S. Surekha, Md Zia Ur Rahman
Submitted On:04-10-2020
Pages:124-133
Action: [Full Paper] No. of Downloads: 138
Manuscript Title:A Double Tuning Fork Shape Printed Antenna with Enhanced Gain and Efficiency for X-band satellite Applications
Manuscript Id:IJMOT-2020-11-102050
Abstract:In this paper, a tuning fork shape microstrip printed antenna for satellite application is reported. The proposed antenna consists of double fork arms and has a dimension of 24?35?1.6 mm3. The defected ground slot in the design improves the impedance bandwidth and overall antenna performance. The antenna is designed on FR4 substrate with permittivity of 4.4 and loss tangent 0.02. The performance of the antenna and optimized dimensions are determined through parametric study. The effects of feed width (WF), tuning fork arm length (LT), fork arm gap (WG), and ground slot length (LG) on antenna performance are analyzed and results are illustrated. A prototype of the antenna is fabricated and measured results are presented to validate the simulation results. The results demonstrate that reflection coefficient is below -10 dB in the 8?11.2 GHz frequency band. It is shown that both E and H field patterns are bidirectional. The simulated peak gain of 5.48 dB (5.24 dB measured value) and 4.84 dB (4.62 dB measured value) are achieved at typical frequencies 8.5 and 10.5 GHz, respectively. It is established that the proposed antenna has increased gain and efficiency as compared to the conventional tuning fork antenna.
Authors:Harikrishna Paik, Hiran Kumar Singh
Submitted On:17-11-2020
Pages:134-141
Action: [Full Paper] No. of Downloads: 34
Manuscript Title:A Compact Wideband DGS Bandpass Filter Based on Half Mode Substrate Integrated Waveguide Technology
Manuscript Id:IJMOT-2020-12-112055
Abstract:In this paper a defected ground structure (DGS) bandpass filter based on half mode substrate integrated waveguide (HMSIW) technology is proposed. We used double circle complimentary split ring resonator (CSRR) as DGS, etched on the top plan of the SIW cavity to constitute a multiple mode resonator and dumbbell DGS etched on the ground plan of the SIW cavity for enhance the filter performances. The taper is used for transition between microstripe to SIW. The simulation results obtained by CST and HFSS show that the proposed filter has a large transmitted bandwidth from 6.2 to 12.7 GHz. The higher simulated insertion loss is about -0.5 dB and the lower return loss is about -48 dB. The size of the designed filter is 60 × 9.8 mm2 which make it more compact compared to other published research works with a size reduction of about 50%. Good rejection are achieved under 6 GHz and upper 13 GHz. Good agreement between CST and HFSS simulation results.
Authors:Nabil Cherif, Mehadji Abri, Benzerga Fellah, Hadjira Badaoui, Junwu Tao
Submitted On:02-12-2020
Pages:142-147
Action: [Full Paper] No. of Downloads: 48
Manuscript Title:Design of GTEM Cell for 915 MHz Exposure Characteristics Study of Biological Mediums
Manuscript Id:IJMOT-2020-12-112061
Abstract:A Gigahertz Transversal Electromagnetic Mode (GTEM) cell has been proven to have an excellent electromagnetic shielding property. It is widely used in the radiation and shielding effects of large equipment such as automobiles but rarely used in studying biological-electromagnetic interaction due to the mismatch between the large GTEM and the small-sized tested biological tissue. In this paper, for the first time, the full cycle design process of a novel reduced size GTEM cell with a length of 1.4 m was addressed using HFSS, including model design, model verification, and biological radiation application analysis. Compared with the conventional TEM cell and radial waveguide, an enormous amount of biological tissue can be measured stably in this novel GTEM cell. Moreover, this GTEM cell structure’s reliability and homogeneity were further verified by analyzing the reflection coefficients (< 15 dB) and the electromagnetic field distribution. Besides, the characterization of different biological mediums’ reaction with different conductivities in a 915 MHz incident electromagnetic waves exposure system was also performed. Finally, the Specific Absorption Rate (SAR) corresponding to the exposed mediums’ ability, placed in the test system, to absorb electromagnetic waves was also evaluated and calculated to be about 0.38 W/kg in the sea-water.
Authors:Zhigang Li, Younes Aimer, Tayeb Habib Chawki Bouazza, Nuraddeen Ado Muhammad
Submitted On:13-12-2020
Pages:148-156
Action: [Full Paper] No. of Downloads: 16
Manuscript Title:Circularly Polarized Microstrip Antenna Deploying Boundary Fractal Geometry
Manuscript Id:IJMOT-2020-12-112065
Abstract:A novel technique to achieve circular polarization deploying triangular and curved boundary fractal is suggested. Parametric studies are carried out for in-phase and out-phase fractal geometry conditions at the patch corner, fractal depth, and order. In-phase with diagonal slot and out-phase geometrical condition, alters the diagonal length yielding circular polarization response. An increase in VSWR bandwidth is due to increased iteration order and depth, which brings higher order modes down. First and second order triangular fractal yields 7.2% and 7.3% axial ratio bandwidth, respectively, with broadside gain more than 7 dBi. The second order in-phase geometrical state of triangular and curved perturbation yields 6.62% and 6.78% of axial ratio bandwidth which is lying inside VSWR bandwidth of more than 39% centered at the frequency 1005 MHz. Proposed work links axial ratio bandwidth with iteration order and depth using resonant length formulations. They provide guidelines for redesigning similar antennas at different frequencies. These antennas can be used for mobile communication systems in the 900 MHz frequency spectrum.
Authors:Anuja A Odhekar, Amit A Deshmukh
Submitted On:24-12-2020
Pages:157-167
Action: [Full Paper] No. of Downloads: 55
Manuscript Title:Characterization of Magneto-Dielectric Materials by a Rectangular Waveguide Using the 2D-FDTD Method
Manuscript Id:IJMOT-2020-12-112068
Abstract:In this paper, a new measurement method is proposed to estimate simultaneously the complex permittivity and the complex permeability for a magneto-dielectric sample using a X-band rectangular waveguide WR90. The Sij-parameters at the reference planes in the rectangular waveguide loaded by a material sample are measured as a function of frequency using the E8634A Vector Network Analyzer. Also, by applying the two-dimensional finite difference in time domain (2D-FDTD), the expressions for these parameters as a function of complex permittivity and complex permeability are calculated. The Nelder-Mead algorithm is then used to estimate the complex permittivity and complex permeability by matching the measured and calculated Sij-parameters. This method has been validated by estimating, at the X-band, the complex permittivity and complex permeability of two materials such as FR4 Epoxy and Titanium Carbide powder (TiC).
Authors:Lahcen Ait Benali, Abdelwahed Tribak, Jaouad Terhzaz, Angel Mediavilla
Submitted On:30-12-2020
Pages:168-174
Action: [Full Paper] No. of Downloads: 21
Manuscript Title:Antenna Array with Non-Uniform Excitation and DNG Hybrid Metasurface for Next Generation Communication Equipment
Manuscript Id:IJMOT-2021-1-122068
Abstract:This paper presents an approach for designing a hybrid metasurface array with Dolph-Chebyshev excitation. The proposed design features a unique feed network. A metasurface consists of a hybrid metamaterial unit cell with five Split Ring Resonators (SRRs) on the bottom and a hexagonal ring made of six triangles on the top surface. The Dolph-Chebyshev amplitude excitation resulted in size reduction. The use of metasurface improves the bandwidth, gain and directivity of the proposed design. A prototype 1x4 array with metasurface is designed for a resonant frequency of 2.4 GHz and fabricated. A high gain of 9.46 dB with a -10 dB impedance bandwidth of 110 MHz is achieved, which amounts to an improvement of 15.28% gain and 31.58% bandwidth compared to conventional uniform excitation array. In terms of overall size, the proposed array antenna is reduced by 38.05% compared to traditional 1x4 microstrip array.
Authors:D Shashi Kumar, Sellakkutti Suganthi
Submitted On:15-01-2021
Pages:175-183
Action: [Full Paper] No. of Downloads: 59
Manuscript Title:A Tri-band Metamaterial Absorber for Radar Cross Section Reduction
Manuscript Id:IJMOT-2021-2-122084
Abstract:In this paper, a new tri-band metamaterial absorber based on crossed sun fractal structure for Radar Cross Section (RCS) reduction is presented. The proposed metamaterial absorber (MMA) exhibits three distinct absorption peaks at 2.2, 5.9 and 6.8 GHz with peak absorption values of 97, 91.6 and 93.3 % respectively. The proposed MMA unit cell is printed on FR-4 substrate with thickness 1.6 mm (0.0117 ????) and compact size 40 mm × 40 mm(0.293 ???? × 0.293 ????), where ???? is the free-spacewavelength with respect to the lowest resonance frequency. Thanks to the new proposed fractal sun shape with sharp edges, we achieve the highest absorption rate at the lowest resonant frequency in comparison with the other published works. In addition, the simple equivalent circuit model is proposed to analyze and predict the frequency of the absorption phenomena of the proposed design. Radar target is characterized by Radar Cross Section (RCS). The surface currents and electric field distributions have been illustrated to understand the mechanism of the structure. In this paper we simulated and calculated the RCS of Perfect Electric Conductor (PEC) and compared this result by a PEC covered by metamaterial sheet. The proposed absorber structure can be used in different applications such as electro-magnetic protections, military and medical applications. All simulation results are performed using the Computer Simulation Technology (CST) Microwave Studio 2018 software, Advanced Design System (ADS) 2017 software, and Mathworks simulation tool MATLAB ver. 2011.
Authors:Mohamed Edries, Hesham A. Mohamed, Sherif S. Hekal, Mohamed A. El-morsy, Hala A. Mansour
Submitted On:24-02-2021
Pages:184-191
Action: [Full Paper] No. of Downloads: 30
OPTICAL RELATED PAPERS
Manuscript Title:Design and Analysis of Free Space Terrestrial Optical Network using SAC-OCDMA and BPSK Modulation
Manuscript Id:IJMOT-2020-10-102042
Abstract:This manuscript elaborates performance of terrestrial free space optical network with Spectral Amplitude Coding (SAC) Optical Code Division Multiple Access (OCDMA) technique. An orthogonal code named as Modified Random Diagonal (MRD) code is assigned to each of the users to minimizes the effect of Multiple Access Interference (MAI) with increased users. This work implements the direct detection technique with Binary Phase Shift Keying (BPSK) modulation. Erbium Doped Fiber amplifier (EDFA) has played the vital role in boosting of the optical signal directly in the optical domain so as to serve huge users with longer link length. The analysis is carried out using OptiSystem 16.0 simulator where the effect of no of users, data rate, transmission distance, weather condition, beam divergence, transmitter and receiver aperture on the Bit Error Rate (BER), Quality factor (Q factor), Received power are carefully observed using BER analyser and Eye Diagram analyser. The optical signal undergoes high attenuation during rainy conditions which can be avoided by decreasing the beam divergence. The role of transmitter and receiver aperture on received power are also clearly presented with the aid of eye diagrams. The reported work though implements 8 users in the system model, yet shows the simulation results for maximum 5 users. The maximum number of users to be supported for various data rates under different propagation conditions are yet to be reported. Thus, we have designed the MRD code for 25 users and used this new code to investigate the maximum number of simultaneous users that can be supported for an acceptable BER at a given link length and for a given data rate. Our EDFA gain is also low which is desirable. Since high gain requires high pump power and more active length in semiconductor PUMP laser.
Authors:Sujata Maharana, Aruna Tripathy
Submitted On:26-10-2020
Pages:192-200
Action: [Full Paper] No. of Downloads: 22
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