| Manuscript Title: | A Compact CPW-Fed Printed UWB Antennas |
| Manuscript Id: | IJMOT-2017-12-1450 |
| Abstract: | In this work, we present the design and analysis of compact coplanar waveguide-fed ultra wideband rectangular antennas. These proposed antennas exhibit very wide operating bandwidth (return loss = -10dB) which covers 3.2-15 GHz range, which means a relative bandwidth of 126% covering FCC defined UWB band with stable omnidirectional radiation patterns and important gain. The parameters of antennas have been investigated and optimized by using two electromagnetic solvers. A good agreement has been obtained between simulation and measurement results. These antennas are useful for UWB indoor applications, handheld and wireless communication requiring low profile antennas. The antennas achieved are low cost and easy to fabricate and integrate with RF circuit. The simulated and the experimental results are described and discussed. |
| Authors: | S. Elajoumi, A. Tajmouati1, J.Zbitou, A. Errkik, L. El Abdellaoui, AM.Sanchez |
| Submitted On: | 3/12/2017 |
| Pages: | 254-262 |
| Action: | [Full Paper]
No. of Downloads: 123 |
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| Manuscript Title: | Beamforming of Smart Antenna in Cellular Network Using Leaky LMS Algorithm and its Variants |
| Manuscript Id: | IJMOT-2018-2-1494 |
| Abstract: | One of the important technologies used in present day cellular network is adaptive smart antenna where cell site is able to communicate in desired direction only and by minimizing undesired interferences. This paper presents modified least mean square (LMS) algorithm as leaky least mean square (LLMS) algorithm and its variants such as sign leaky least mean square (SLLMS) and normalised leaky least mean square (NLLMS) for beamforming in smart antenna (SA). A comparative analysis of beamforming using the above stated algorithms is done based on main beam direction, null direction, maximum side lobe level (SLLmax) and convergence by varying the step size. |
| Authors: | Ritika Sharma, Anupama Senapati, Jibendu Sekhar Roy |
| Submitted On: | 9/2/2018 |
| Pages: | 263-268 |
| Action: | [Full Paper]
No. of Downloads: 32 |
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| Manuscript Title: | A Miniaturized Rat-Race Microstrip Coupler by Using Open Stubs for LTE Applications |
| Manuscript Id: | IJMOT-2018-2-1495 |
| Abstract: | This paper presents a study and analysis of a high performance microstrip rat-race coupler (RRC) operating at 2.2 GHz for higher LTE (1.7 - 2.7 GHz) frequency band application. High and low impedance transmission line are used to miniaturize the conventional coupler. The proposed RRC is utilized from T-shape line technique are used to miniaturize structure. The design and simulated results are validated by electromagnetic simulation (by Method of Moments (MOM) using the Advance Design System (ADS) tool from Agilent technologies), which confirms the theory and validates the proposed coupler design. After this validation into simulation. The rat-race 180° coupler (RRC) which has been fabricated relying on a low cost material using a substrate material of FR-4 and tested using a Rohde and Schwarz ZVB 20 vector network analyzer. The size of the implemented rat-race coupler is 76.11×35.86 mm², which is 31.51% compared to the conventional. Also, the isolation coefficient, the reflection and the phase difference between output ports are as good agreement results. |
| Authors: | Mahmoud Moubadir, Mohamed Bayjja, Naima Amar Touhami, Mohamed Aghoutane |
| Submitted On: | 13/2/2018 |
| Pages: | 269-276 |
| Action: | [Full Paper]
No. of Downloads: 59 |
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| Manuscript Title: | Multi-tone Measurements of Continuous Class-F Power Amplifier |
| Manuscript Id: | IJMOT-2018-3-1508 |
| Abstract: | The measurement and characterization of high power amplifiers using multi-tone signals provide an end user relevant means of investigating linearity through adjacent channel power (ACP) distortion analysis. This paper presents multi-tone measurements and experimental baseband load-pull characterization of a continuous mode class-F power amplifier when operated under complex multi-tone excitations. All of the measurements were carried out using an enhanced multi-tone waveform measurement system that allows multi-tone stimuli and the synthesis of constant and frequency independent broadband loads at both RF and baseband frequencies. This paper builds on previous research by increasing the number of tones being used to characterize and measure the amplifier. |
| Authors: | Muhammad Akmal Chaudhary |
| Submitted On: | 11/3/2018 |
| Pages: | 277-282 |
| Action: | [Full Paper]
No. of Downloads: 34 |
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| Manuscript Title: | Miniaturized Wideband/Broadband Microstrip Slotted Rectangular Patch Antenna for Multiple Applications |
| Manuscript Id: | IJMOT-2018-3-1509 |
| Abstract: | The design of a miniaturized microstrip slotted rectangular patch antenna for fixed mobile and radio location applications has been proposed in this paper. A 13.5 mm x 3 mm miniaturized rectangular patch slotted in ways to achieve multiband performance with exorbitantly high gains has been built over a 16 mm x 5.8 mm x 1.6 mm FR-4 epoxy substrate that has a relative permittivity of 4.4 and a dielectric loss tangent of 0.02. The slotted patch bears the name of the father of the first author and appears to be a kind of desk plate. Coaxial feed has been used. The prototype has been designed over FEM based HFSS-15 and analyzed for its reflection coefficient, bandwidth, radiation pattern, gain, directivity and VSWR at the different resonant frequencies. The results so obtained have been found to approximate the experimentally verified results of the fabricated structure. Wideband characteristics (bandwidth greater than 2%) are achieved around 10.11 GHz while the second band achieves broadband (the ratio of upper and lower side frequencies should be 2) characteristics. The bandwidth characteristics so obtained clearly indicate the par excellent performance of the proposed structure over the reviewed works. |
| Authors: | Deepanshu Kaushal, T. Shanmuganantham |
| Submitted On: | 11/3/2018 |
| Pages: | 283-289 |
| Action: | [Full Paper]
No. of Downloads: 74 |
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| Manuscript Title: | High Isolation Dual-band MIMO Antenna Based on a Novel Structure of Gradient Lines |
| Manuscript Id: | IJMOT-2018-3-1512 |
| Abstract: | In this study, a metamaterial antenna which uses coplanar wave (CPW) guide feeding and modified composite right/left handed (CRLH) model to get dual-band and compact size is proposed. The antenna operates at 3.5 GHz and 5 GHz with bandwidth of 22% and 3.13% respectively for LTE/Wimax, future 5G and WLAN applications in portable devices. Implemented in RO4350B substrate with height of 1.52 mm, the antenna gets compact in size with radiating patch dimension of 5.5x12.5 mm2. A MIMO antenna is constructed by placing side by side two single metamaterial antennas with distance of nearly a haft of wavelength. Using a novel structure of gradient lines on radiation plane, the mutual coupling of MIMO antenna reduces significantly with an operating band which is able to widen for 5G communication. This characteristic can not achieve in almost previous decoupling structures. Besides, the widen-stop-band capability of the proposed structure is indicated by equivalent circuit with frequency response of decoupling structure. |
| Authors: | Duong Thi Thanh Tu, Nguyen Tuan Ngoc, Vu Van Yem |
| Submitted On: | 14/3/2018 |
| Pages: | 290-298 |
| Action: | [Full Paper]
No. of Downloads: 52 |
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| Manuscript Title: | EC-SRR Inspired CPW-Fed Triple Band Antenna with Staircase Shaped Ground Plane for WLAN and C-band Applications |
| Manuscript Id: | IJMOT-2018-4-1533 |
| Abstract: | In this paper, Edge-Coupled Split Ring Resonator (EC-SRR) inspired triple band antenna is presented. The proposed antenna consists of CPW-fed EC-SRR inspired radiating element with a staircase ground plane. The proposed antenna with a compact size of 31 × 25 × 1.6 mm3 is fabricated and tested to validate against the simulation results. The operating resonant frequencies of the proposed antenna are 2.8 GHz, 4.3 GHz and 5.2 GHz. Simulated and measured results show that the proposed antenna would be suitable one for WLAN and C-band applications. Design methodology of EC-SRR is deliberated with the help of quasi-static analysis, and the equivalent circuit parameters are computed. The retrieval method to find the negative permeability of the EC-SRR is discussed in detail. Good agreement between the simulated and measured results are observed. Also, stable radiation characteristics are inferred in the resonant frequency of interest. Parametric studies have been performed to illustrate the motive of EC-SRR as a radiating element and a staircase structure as a ground plane. |
| Authors: | N. Thamil Selvi, P. Thiruvalar Selvan, SPK. Babu |
| Submitted On: | 9/4/2018 |
| Pages: | 299-309 |
| Action: | [Full Paper]
No. of Downloads: 47 |
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| Manuscript Title: | A Linearity Improvement Technique for Two-Stage Amplifiers with Second Harmonic Driving |
| Manuscript Id: | IJMOT-2018-5-1577 |
| Abstract: | This paper presents a linearity improvement technique for two-stage nonlinear amplifiers. Third-order intermodulation terms (IM3) at the output of an amplifier can be cancelled out by second harmonic injection at the input. The first stage is biased at highly nonlinear bias point to generate second harmonic. A dual-band interstage network between the first stage and the second stage is implemented to cover the fundamental and the second harmonic frequencies. Then, large second harmonic terms are injected to the input of the second stage. With appropriate biasing of two amplifiers and second harmonic phase shifting at the interstage network, the IM3s are cancelled out at the output of the second stage. A two-stage amplifier has been designed and implemented with discrete transistors on a PCB. The measurement results show 10-dB suppression on the IM3 at 920 MHz. |
| Authors: | Joon Hee Lee, Gyun Tae Kim, Jusung Kim, Ockgoo Lee, Kwang-Jin Koh, Dong-Ho Lee |
| Submitted On: | 27/5/2018 |
| Pages: | 310-316 |
| Action: | [Full Paper]
No. of Downloads: 49 |
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| Manuscript Title: | Design and Calibration Procedure of a Proposed V-band Antenna Array on Fused Silica Technology Intended for MIMO Applications |
| Manuscript Id: | IJMOT-2018-5-1583 |
| Abstract: | A coplanar-fed wideband antenna array system to characterize MIMO channels in the 60 GHz band is proposed. The array consists of six U-slot patch elements with half-wavelength separation and is fed independently by individual transceivers. The system is designed and simulated on fused silica substrate to be integrated easily with RFICs and to achieve fine fabrication resolution (1um) for accurate mm-wave measurements. It can provide 11dBi peak gain at broadside and beam steering up to ±40° tilted from broadside over 57-63 GHz band. A new on-wafer calibration technique is developed to balance the amplitude and phase of all transceivers at the input of the array system which realizes high accuracy for beam steering purposes. |
| Authors: | Mahdi Salarpour, Forouhar Farzaneh, Robert Bogdan Staszewski |
| Submitted On: | 30/5/2018 |
| Pages: | 317-329 |
| Action: | [Full Paper]
No. of Downloads: 31 |
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| Manuscript Title: | A Modified Monopole Antenna with Switchable Band Notch for UWB Applications |
| Manuscript Id: | IJMOT-2018-5-1584 |
| Abstract: | This article presents a modified monopole antenna with switchable WLAN band rejection for ultra-wideband (UWB) applications. The proposed design consists of a modified circular monopole antenna integrated with band notch structure based on defected microstrip structure (DMS). The modified antenna provides wide impedance bandwidth, and the DMS provides band notch to reject WLAN frequency band at 5.5 GHz. The switchability feature is realized by using an ideal switch inserted in the DMS. The results show that the proposed design exhibits a wide impedance bandwidth from 3 to 14 GHz with switchable band notch at 5.5 GHz, and omnidirectional radiation pattern. |
| Authors: | Ammar Alhegazi, Zahriladha Zakaria, Noor Azwan Shairi, Sharif Ahmed |
| Submitted On: | 31/05/2018 |
| Pages: | 330-336 |
| Action: | [Full Paper]
No. of Downloads: 40 |
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| Manuscript Title: | Substrate Integrated Waveguide Band-pass Filter for X Band Applications |
| Manuscript Id: | IJMOT-2018-5-1585 |
| Abstract: | Substrate integrated waveguide presents the perfect solution that we can use specially in microwaves, radar applications and mobile communication. This paper presents the design, the simulation, and the fabrication of a substrate integrated waveguide band pass filter having 0.5dB pass band ripple, the bandwidth of the filter is about 13% the return loss is about 34dB at 10.5 GHz. Simulation results are in good agreement with the measured one. |
| Authors: | Imane Badaoui, Naima Amar Touhami, Sanaâ Finish, Mohammed Lamsalli |
| Submitted On: | 31/05/2018 |
| Pages: | 337-342 |
| Action: | [Full Paper]
No. of Downloads: 55 |
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| Manuscript Title: | Novel compact patch antenna for Ultra-wideband (UWB) applications |
| Manuscript Id: | IJMOT-2018-6-1589 |
| Abstract: | In this paper, a new ultra-wideband (UWB) antenna is proposed for C-band satellites applications. The main objective of this work is to design an ultra-wideband omnidirectional antenna with a high gain. The proposed antenna is supposed to cover the UWB range from 7.8 GHz to 10.25 GHz for radar applications, and the frequency of 6.3GHz for land stations for satellites. Such a wideband from 7.8 to 10.25GHz is achieved using different slots technologies by etching various shaped slots in the radiating patch. The final antenna has almost invariant radiation properties and reasonable omnidirectional radiation patterns with a gain up to 9.77dB. The antenna is designed on an FR4 substrate with dimensions of (40 × 40 ×1.6mm3). The details of the simulated and measured results for reflection coefficient, gain surface Current distributions and radiation patterns are presented and discussed. |
| Authors: | M. Hamza QADDI, Marko SONKKI, Sami MYLLYMAKI, Hassan MHARZI M. Nabil SRIFI, Heli JANTUNEN |
| Submitted On: | 3/6/2018 |
| Pages: | 343-350 |
| Action: | [Full Paper]
No. of Downloads: 59 |
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| Manuscript Title: | Patch Antenna Using Z-Slot for Bandwidth Improvement for 5G Network Applications |
| Manuscript Id: | IJMOT-2018-6-1592 |
| Abstract: | This paper presents the design and the simulations of a novel planar broadband microstrip antenna. The antenna structure has been designed based on microstrip line combined with a slot technique and a modified geometry in order to enlarge the bandwidth, adapting the impedance and reaching the suitable gain. The structure parameters have been investigated and optimized by using CADFEKO before the antenna achievement. The final patch antenna has a bandwidth from 18.48 GHz to 19.60 GHZ with a return loss less than -10dB. |
| Authors: | Kamal BOUZAKRAOUI, Ahmed MOUHSEN, Mohamed TAOUZARI |
| Submitted On: | 7/6/2018 |
| Pages: | 351-358 |
| Action: | [Full Paper]
No. of Downloads: 58 |
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| Manuscript Title: | Space-Time Codes in Free Space Optical Communications: A Case for Improved Spectral Efficiency |
| Manuscript Id: | IJMOT-2017-11-1433 |
| Abstract: | Space-time coding (STC) in RF systems has been widely researched, and owing to its wide success, STC is currently gaining growing attention for free space optical (FSO) communication systems as they are now being deployed in order to mitigate link performance degradation as a result of turbulence. In this paper, the impact of several variants of space-time codes in free space optical communication systems was examined and the discord in the subject of whether the deployment of STC improves the performances of FSO systems or not, are harmonized. A space-time trellis code for coherent FSO system was presented and its performance was analyzed. This work concludes by highlighting the promising potentials of STCs in coherent FSO systems and identifies suitable coding schemes for these systems. |
| Authors: | Ojo Adedayo, Ilesanmi Oluwafemi, Owolabi Esan |
| Submitted On: | 14/11/2017 |
| Pages: | 359-368 |
| Action: | [Full Paper]
No. of Downloads: 46 |
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| Manuscript Title: | Modeling and Optimization of ECDL for Efficiently Tuning Continuous Unidirectional UV-C Light |
| Manuscript Id: | IJMOT-2018-3-1510 |
| Abstract: | We demonstrate the modeling of an External Cavity Diode Laser (ECDL) that can efficiently tune to any wavelength in the UV-C band. The principle of tuning is based on an effective combination of Littrow and Littman-Metcalf configuration. Our developed model can also reduce the output beam linewidth by 33%, which alternately improves the tuning efficiency. Mode hopping, which is an underlying complication in this form of systems, is hereby suppressed effectively by determining a suitable pivot point. Unlike previous models where mode-hop free tuning is achieved only within one free spectral range, our system is designed for full mode-hop free operation. Also, our system can yield a maximum efficiency of greater than 80% which is achieved by s-polarizing the feedback beam. The application of this system can span from non-line-of-sight communication to spectroscopy. |
| Authors: | Avra Bhattacharjee, Erfanul Hasib, Jobaida Akhtar, Mohammad Istiaque Reja |
| Submitted On: | 12/3/2018 |
| Pages: | 369-376 |
| Action: | [Full Paper]
No. of Downloads: 60 |
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