| Manuscript Title: | New CPW-fed Broadband Circularly Polarized Planar Monopole Antenna Based on a Couple of Linked Symmetric Square Patches |
| Manuscript Id: | IJMOT-2019-11-11851 |
| Abstract: | A new broadband circularly polarized planar monopole antenna with coplanar waveguide feeding (CPW-fed) is proposed. This antenna consists of a couple of linked symmetric square patches (CLSSP), an asymmetric ground plane and two strips connected to the left ground plane by the CLSSP radiator and a straight strip. A broad impedance bandwidth (IBW) is achieved. Moreover, a broad axial ratio bandwidth (ARBW) is obtained by using an asymmetric ground plane and an inverted L-shaped strip. Simulation results demonstrate that IBW reaches 119% (1.56–6.18 GHz) and ARBW is 88.9% (2–5.2 GHz). The latter is completely overlapped by the simulated IBW. In addition, antenna performance is investigated by studying different parameters. |
| Authors: | Hussein ALsariera , Zahriladha Zakaria, Azmi bin Awang Md Isa, Sameer Alani, Othman Al-Heety, mohammed zeain, Sharif Qasem |
| Submitted On: | 02-11-2019 |
| Pages: | 95-103 |
| Action: | [Full Paper]
No. of Downloads: 90 |
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| Manuscript Title: | A novel Compact Ultra BroadBand CPW LowPass Filter Using A Periodic Z-Shaped Stubs with Excellent StopBand Rejection |
| Manuscript Id: | IJMOT-2019-12-11873 |
| Abstract: | In this paper, A novel compact, ultra-broadband coplanar-waveguide (CPW) lowpass fllter (LPF) is presented. The proposed Lowpass filter (LPF) covers the ultra wideband (UWB) frequency range of 0.1GHz to 14GHz in the passband . The compact filter uses three periodics Z-shaped stubs connected to the conductor line of cpw structure to achieve high quality bandpass and band-rejection performance. Compared with the classical CPW-LPFs, the proposed filter is simple, low cost for fabrication and easy to associate with others microwave planar circuits because the free ground plane of structure. The proposed CPW Low pass filter has sharp selectivity, and great stopband rejection with an insertion loss less greater than 50dB. Good agreement between equivalent circuit and electromagnetic simulation response is demonstrated. The cutoff frequency of the proposed low pass filter can be change by tuning the dimensions of Z cell. |
| Authors: | Elmahjouby Sghir,Ahmed Errkik, Jamal Zbitou, Mohamed Latrach |
| Submitted On: | 03-12-2019 |
| Pages: | 104-112 |
| Action: | [Full Paper]
No. of Downloads: 268 |
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| Manuscript Title: | Design of Dual Sense, Dual Frequency Circularly Polarized Slot loaded and Corner Sliced Microstrip Antenna using Stacked and Reconfigurable Scheme |
| Manuscript Id: | IJMOT-2019-12-11878 |
| Abstract: | Mode disintegration using diagonal square slots, sliced corners of proximity fed antenna is proposed to obtain circular polarization (CP). Empirical formulation, redesign algorithm for degenerate modes resonant length are distinctiveness of work .Stacked dual band, dual CP antenna is designed using formulations. It results Right Hand CP (RHCP) at 944 MHz, Left hand CP (LHCP) at 1105 MHz with CP bandwidth of 5.1 %, 5.6 %. Diode switching and its position controls stub length for reversing sense of CP is proposed in another technique. It gives RHCP at 966 MHz, LHCP at 875 MHz with CP bandwidth of 5.1 %, 5 %. For both techniques gain of 7 dB, cross polar below 23 dB is achieved at both polarizations. Redesign Flexibility at preferred frequency ratio, ease in fabrication, installation makes it suitable for mobile, satellite communication.
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| Authors: | Anuja A Odhekar, Amit A Deshmukh |
| Submitted On: | 07-12-2019 |
| Pages: | 113-121 |
| Action: | [Full Paper]
No. of Downloads: 32 |
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| Manuscript Title: | Accurate Closed-Form Formulas for the Electromagnetic Parameters of a New Low-Loss High Performance quasi-TEM Sliced Coaxial Coupler |
| Manuscript Id: | IJMOT-2019-12-11886 |
| Abstract: | Coupled coaxial lines have long history of
application in microwave and RF circuits. In this
work, we present, for the first time, simple and
concise formulas for the electromagnetic (EM)
parameters of a new low-loss, high performance
quasi-TEM sliced coaxial coupler, convenient for
high-power and high-frequency applications. The
proposed configuration allows a wide range of
coupling coefficients from 2.5 to 61 dB with low
losses and reduced dispersion. Based on finite
element method (FEM) analysis and by solving the
Laplace equation in two dimensions (2D), the study
of the proposed coupler is realized under FreeFEM
environment. In order to validate our numerical
results, we have adapted our FEM-program to
characterize the structure of interest for the
homogenous case. Our FEM-results are very close
with those obtained by other methods of the
scientific literature. In a quasi-TEM
approximation of the present work , we focus
mainly on determining the even- and odd-mode
characteristic impedances (Z0e, Z0o), the even- and
odd-mode effective dielectric constants (e0eff, e0odd),
coupling coefficient (k), and the primary inductive
and capacitive matrices ([L], [C]). The effects of
cut depth (u) and dielectric radius to the innerconductor
radius (w/rc) ratios on the EMparameters
have been taken into account. When
the quasi-TEM parameters were determined, we
have applied curve-fitting techniques under
origin50 graph environment to find new simple,
concise formulas for all the EM-parameters of the
quasi-TEM sliced coaxial coupler. The difference
between the calculated numerical values using our
CAD program based on the FEM and the derived
equations is less than 2% over a wide range of
design parameters. Using these analytical models,
an analysis can be readily implemented in modern
CAE software tools for the design of high-power
and high-frequency microwave and wireless
components. To show the usefulness of the design
equations, 50 O, 7-dB and 27-dB, microwave
compact directional quasi-TEM sliced coaxial
couplers with only 8.034×5.6×7.2 mm3 and
10.71×5.6×11.8 mm3, of size, operating at 10 GHz
and 5 GHz, respectively, will be designed. |
| Authors: | Djamal Lachachi, Yamina Bekri, Nadia Benabdallah, Abdelhakim Boudkhil, Mohammed Chetioui, Nasreddine Benahmed |
| Submitted On: | 11-12-2019 |
| Pages: | 122-131 |
| Action: | [Full Paper]
No. of Downloads: 37 |
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| Manuscript Title: | Double layer Stacked Annulus-Shape Quad Resonant Textile Antenna with Defected Ground for WLAN/WiMAX/Bluetooth/Hiper LAN Applications |
| Manuscript Id: | IJMOT-2019-12-11888 |
| Abstract: | This paper presents a new and improved
design of low profile stacked antenna fabricated on
textile substrate to facilitate the manufacture of the
wearable antenna. It provides enhanced impedance
bandwidth and multiband operation along with its
wearable characteristics that makes it sound for
practical applications such as WLAN, WiMax,
Bluetooth, and Hiper LAN. It’s distinctive design,
structure and optimized dimensions makes it
unique as compared to various antennas reported
earlier in literature. The proposed antenna design
employs jeans fabric and cotton as two substrates
and copper tape (thickness =0.038 mm) is used to
make its conducting parts. This antenna comprise
of defected ground plane, parasitic patch and the
driven radiating patch connected through 50 O
microstrip feed line. Quad band operation is
possible by etching concentric circular slots in
circular patch on upper and lower substrate. The
antenna bandwidth is increased by properly
choosing the radius of the concentric annulus
patches and feed line. The analysis of presented
antenna has been carried out in terms of return
loss, cutoff frequency, center frequency and
percentage bandwidth. This anticipated antenna
provides usable bandwidths from 1.416 GHz to
1.64 GHz, 1.712 GHz to 2.164 GHz, 2.276 GHz to
2.804 GHz and 2.92 GHz to 5.0 GHz. The
prototype of the proposed antenna has been
fabricated and tested. The experimental results
closely match with the simulated results. |
| Authors: | Mohit Gaharwar, D. C. Dhubkarya |
| Submitted On: | 16-12-2019 |
| Pages: | 132-140 |
| Action: | [Full Paper]
No. of Downloads: 50 |
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| Manuscript Title: | Electromagnetic Analyses and Designs of Shielded UHF MRI-probes using Rectangular-tube and Parallel-plate Resonators |
| Manuscript Id: | IJMOT-2019-12-11889 |
| Abstract: | Magnetic Resonance Imaging (MRI) is
widely used in medical applications to visualize the
inner part of human body. Radiofrequency (RF)
coils form a crucial element in any MRI system
because the use of coils which fit around parts of
the human body to be imaged is important to
obtain high-quality images and spectrums. The
purpose of this study is to characterize, analyse
and design for imaging applications two shielded
UHF MRI-probes operating at 300 MHz (7 Tesla)
and using rectangular tube (RTR) and parallelplate
(PPR) resonators. Our numerical analyses
tool consisted of the method of moments (MoM)
under LINPAR environment. The simulation
output provides the primary ([L] and [C]) matrices
and the values of the even- and odd-mode
characteristic impedances (Z0e and Z0o) of the
resonators. By applying the TLM method, the
reflection coefficients and the quality factors of the
loaded or unloaded UHF MRI-coils are calculated
and the effects of various geometrical parameters
are studied. Two shielded UHF MRI-probes using
rectangular tube and parallel-plate resonators
have been built to operate at 7 T (300 MHz). These
probes are small size, cheap, compact and easy to
fabricate. |
| Authors: | Kamila Aliane, Djamal Lachachi, Yamina Bekri, Nadia Benabdallah, Nasreddine Benahmed |
| Submitted On: | 17-12-2019 |
| Pages: | 141-150 |
| Action: | [Full Paper]
No. of Downloads: 25 |
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| Manuscript Title: | Design and Analysis of Circularly Polarized Dual Patch Antenna with Improved Isolation for MIMO Satellite Application |
| Manuscript Id: | IJMOT-2019-12-11894 |
| Abstract: | The design of circularly polarized dual microstrip patch antenna for Satellite Multiple Input Multiple Output(MIMO) application at 4GHz is presented. The reduced mutual coupling and circular polarization are achieved by incorporating diagonal slots, stubs on end of the patch and L shaped microstrip stubs in between two antennas. Two orthogonal modes are generated with equal magnitude and 90° phase shift by employing these slots. The simulated results are studied and analyzed for the proposed antenna. The isolation of better than 20dB, axial ratio lower than 3 dB and gain of about 5dB are obtained. The performance characteristics are simulated, measured and analyzed with different antenna parameters. The validated antenna shows that the simulated results agree well with measured antenna parameters.
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| Authors: | Jayakumar M, Megha M Kartha |
| Submitted On: | 19-12-2019 |
| Pages: | 151-158 |
| Action: | [Full Paper]
No. of Downloads: 70 |
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| Manuscript Title: | Pentagonal Slotted Single Element Microstrip Textile Antenna with Defected Ground for Ultra Wide Band Applications |
| Manuscript Id: | IJMOT-2019-12-11895 |
| Abstract: | This paper proposes a single element microstrip based, low profile textile antenna for on-body UWB applications having overall size of 61 x 61 mm2. CST Microwave Studio is used for designing and simulation purpose. To make the antenna wearable, jeans fabric have been utilized as a substrate and copper tape is used to make its conducting parts. Besides being wearable, the designed antenna shows UWB characteristics having BW of 128.91 % (2.308 GHz - 10.679 GHz) with a single band notch from 8.864 GHz to 9.205 GHz and BW of 117.36 % (2.308 GHz - 8.864 GHz) without any band notch. The combined effect of defected ground plane and a pentagonal slotted circular radiating patch makes the proposed antenna to achieve highest percentage bandwidth and bandwidth ratio among all compared various UWB antennas reported earlier in literature. This antenna best resonates at 6.73 GHz and 7.61 GHz with deliberate directivity of 3.471 dBi and 3.725 dBi respectively. Total efficiency is above 91.9% for most of the frequency band. A prototype of the design is also fabricated and measurements in terms of return loss, impedance bandwidth, percentage bandwidth and far field radiation patterns have been carried out in order to validate the simulated results which show good correlation. |
| Authors: | Rajesh Kumar, D. C. Dhubkarya |
| Submitted On: | 23-12-2019 |
| Pages: | 159-167 |
| Action: | [Full Paper]
No. of Downloads: 32 |
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| Manuscript Title: | Flower Shaped Elliptical Patch Antenna for UWB Applications |
| Manuscript Id: | IJMOT-2020-1-11903 |
| Abstract: | This paper presents a new approach to antenna design with broad bandwidth and good omnidirectional radiation patterns in a frequency range that exceeds the UWB. The proposed antenna has three-elliptically shaped patches in a configuration inspired from the shape of flowers; (an elliptical patch at the center between two identical elliptical patches). The antenna, which is constructed on an FR-4 epoxy substrate with er =4.3 has a compact size of 25mm×25mm×1.45mm. Two rectangular slots were cut in the ground plane in order to enhance the gain of the proposed antenna at higher frequencies. Parametric analyses are performed using the CST Microwave Studio version 2018, and the optimized design was fabricated. The antenna achieved a relative bandwidth of 136%, covering the frequency range 3.1GHz to 16.243GHz. The simulated and measured S11 results are in good agreement. |
| Authors: | Asmaa H. Majeed, Khalil H. Sayidmarie |
| Submitted On: | 20-01-2020 |
| Pages: | 168-178 |
| Action: | [Full Paper]
No. of Downloads: 45 |
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| Manuscript Title: | Performance of Smart Antenna in Cellular Network Using Variable Step-Size Algorithms |
| Manuscript Id: | IJMOT-2020-1-11907 |
| Abstract: | Beamforming in smart antenna as well as side lobe level (SLL) reduction are important tasks in mobile network. The aim of this paper is to compare the performances of some variable step-size algorithms for adaptive beamforming in smart antenna, because fixed step size adaptive algorithms have limitations in beamforming of smart antenna. Beamforming using variable step-size least mean square (VS-LMS), variable step-size sign least mean square (VS-SLMS) and variable step-size normalized least mean square (VS-NLMS) algorithms are reported here. Linear antenna array of 8 elements and 20 elements with different inter-element spacing are used for adaptive beamforming. Comparative studies show that lowest side lobe levels are achieved in case of VS-NLMS algorithm and convergence of VS-SLMS algorithm is better compared to other algorithms. |
| Authors: | Barsa Samantaray, Kunal Kumar Das, Jibendu Sekhar Roy |
| Submitted On: | 28-01-2020 |
| Pages: | 179-186 |
| Action: | [Full Paper]
No. of Downloads: 54 |
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| Manuscript Title: | Reconfigurable radiation pattern antenna using kite-shaped parasitic patches for Wireless Access applications |
| Manuscript Id: | IJMOT-2020-1-11908 |
| Abstract: | This work presents reconfigurable radiation pattern antenna using four parasitic patches. The pattern-reconfigurable planar antenna proposed achieves four reconfigurable states by controlling the ON and OFF of four PIN diodes to change the direction. The state change is performed by PIN diodes connected in the gap between the central square patch and parasitic patches. A short circuit or an open circuit can be provided by this gap. The measured band of the all states has a bandwidth of 4,7%. The antenna main beam can be switched to four directions in elevation plane. The goal is to provide wider coverage by redirecting the main lobe. Simulated and measured results are also presented and investigated. |
| Authors: | F. Rahmani, N. A. Touhami, A. B. Kchairi, N. Taher, M. El Ouahabi |
| Submitted On: | 30-01-2020 |
| Pages: | 187-195 |
| Action: | [Full Paper]
No. of Downloads: 82 |
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| Manuscript Title: | Uncladded Fiber Bragg Grating Etched with Nitric Acid for Glucose Concentration Measurement |
| Manuscript Id: | IJMOT-2020-1-11901 |
| Abstract: | In this study, we present an investigation of uncladded fiber bragg grating (FBG) as a chemical sensor towards glucose in an aqueous solution with various concentrations from 0 – 60 wt%. Uncladded fiber bragg gratings have been etched with nitric acid (HNO3) therefore acting as a sensing element. Two measurement methods consisting of optical spectrum analyzer (OSA) and spectrometer systems were performed. We compare which method shows the best response from uncladded FBG as a glucose concentration detection. The measured parameter is the wavelength shift in OSA system, while in spectrometer system is optical intensity. It was found that the uncladded FBG exhibits the response towards glucose concentration variations for both measurement methods. The results show that the OSA method is better because the sensitivity is larger. This sensor can be developed further to be coated by some sensitive materials to enhance its performance. |
| Authors: | Nur Abdillah Siddiq, Asnawi Asnawi, Endah Rahmawati, Nur Qomariyah, Yono Hadi Pramono |
| Submitted On: | 15-01-2020 |
| Pages: | 196-202 |
| Action: | [Full Paper]
No. of Downloads: 30 |
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| Manuscript Title: | Analysis of Reflection Spectrum of Uniform Fiber Bragg Grating Having Air Holes in the Cladding |
| Manuscript Id: | IJMOT-2020-1-11906 |
| Abstract: | The reflection spectrum of fiber Bragg grating mainly depends on grating length, change in refractive index and profile of the refractive index. In this paper, we propose a uniform fiber Bragg grating having air holes in the cladding to study the reflection spectrum. The air filling fraction of the air holes can affect the reflection spectrum. Fully vectorial effective index method and coupled mode theories are used to analyze the proposed Bragg grating. The results show that the change in air filling fraction affect the reflectivity, full width at half maximum, side lobe strength, group time delay and dispersion. It is concluded that air filling fraction can be used as one of the design parameters of fiber Bragg gratings in practical applications. |
| Authors: | M P Srinivasa Rao, Vivek Singh |
| Submitted On: | 27-01-2020 |
| Pages: | 203-210 |
| Action: | [Full Paper]
No. of Downloads: 38 |
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