International Journal of Wireless and Microwave Technologies @ijwmt
Статьи журнала - International Journal of Wireless and Microwave Technologies
Все статьи: 596
Compact MIMO Shorted Microstrip Antenna for 5G Applications
Статья научная
The objective of the work is to design a compact MIMO antenna at 3.5 GHz suitable for 5G applications. MIMO antenna is suitable choice for increasing the signal to noise ratio of mobile communication systems. The channel capacity can be increased by improving signal to noise ratio. At the same time, high isolation between the elements should be maintained. Planar inverted F antenna (PIFA) is used as a unit element for MIMO antenna in this work. The unit element dimensions are 9.5 x 7 mm2. Two shorting pins are used for getting better impedance matching. Four elements are arranged in the FR4 substrate with dielectric constant 4.4 and thickness of 1.6 mm. The performance of 4 element Multiple Input Multiple Output (MIMO) antenna is optimized using HFSS software. The results show that the better impedance matching at desired frequency band and a gain of 4.2 dB in the bore-sight axis is obtained for the four elements. The gain of four element antenna is improved from - 0.52 dB to 4.2 dB than two element antenna. The isolation between the elements is obtained below -15 dB . The overall volume of the antenna is 25.3 x 26.8 x 1.6 mm3, which ensures compactness suitable for mobiles.
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Compact UWB BPF with a Tunable Notched Band based on Triple-mode HMSIW Resonator
Статья научная
A novel triple-mode resonator based on the half-mode substrate integrated waveguide (HMSIW) structure is proposed to design the ultra-wideband (UWB) filters. The UWB filter topology is given by analyzing the resonant frequencies of the three modes and the signs of the coupling between the three modes and the input/output ports. With the filter synthesis method, a triple-mode UWB filter with passband from 3.1-10.6 GHz is effectively realized with two transmission zeros at the upper stopband. To block the existing undesired narrowband radio signals in FCC UWB range, a notched band can be easily generated and controlled by a loaded stub-capacitor. For demonstration, an UWB filter with a tunable notched band from 3.7 to 7.7 GHz and compact size is designed and fabricated. Both simulated and measured results indicate that the proposed new filter has the properties of wide tuning range of the notched band and sharp roll off.
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Compact Ultra-wideband Bandpass Filter with Wide Fractional Bandwidth and High Skirt Selectivity
Статья научная
A compact ultra-wideband bandpass filter having highly selectivity and wide bandwidth simultaneously is proposed, which adopts a modified multiple-mode resonator (MMR) and annular structures. The modified MMR is constructed by multiple uniform-impedance stubs and a dumbbell-based stepped-impedance stub. Two transmission zeros are created by the dumbbell-based stepped-impedance stub at the lower and upper cutoff frequencies to improve the selectivity. Additionally, two annular defected ground structures in the aperture ground are adopted to enhance the coupling factor and reduce the etching size. This bandpass filter has a fractional bandwidth of 127% with selectivity of up to 0.939. The measured results are in good agreement with the simulation results.
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Compact antenna analysis in terms of wave transmission modes
Статья научная
The electrically compact microstrip antenna is studied with analysis of different modes of transmission. The design of a rectangular microstrip antenna (RMSA) is implemented for a Bluetooth band. The parallel shorting plate is inserted to reduce size which in turn shifts the null point of the patch to the position of the plate and excited the mode below its fundamental operating mode i.e. TM00 mode. IE3d simulator is used to analyze the mode of transmission in terms of the current path. Simulated and measured results validate the hypothesis made of the fact of the mode of transmission.
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Comparative Analysis of Macro-Femto Networks Interference Mitigation Techniques
Статья научная
When interference is reduced, the benefits of using a macrocell and femtocell heterogeneous network (Macro-Femto) heterogeneous network (HetNet) can be increased to their full potential. In this study, Enhanced Active Power Control (EAPC), Active Power Control (APC), and Power Control (PC1) interference mitigation strategies are applied, and their performances in uplink and downlink transmission of 5G Non-Stand-Alone (NSA) architecture are compared. According to the findings of a MATLAB simulation, the EAPC technique utilized a lower amount of transmit power for the Macro User Equipment (MUE), the Home User Equipment (HUE), and the femtocell logical node (Hen-gNB), in comparison to the APC and PC1 techniques. While PC1 approach required less en-gNB transmission power. The MUE, HUE, hen-gNB, and en-gNB throughput of the EAPC approach was much higher. This work will enable wireless system designers and network engineers know the appropriate technique to utilize to achieve desired Quality of Service (QoS) while conserving network resources.
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Comparative Analysis of Various Inter-Carrier Interference Cancellation Methods
Статья научная
This paper provides a review of various inter carrier interference cancellation methods used in Orthogonal Frequency Division Multiplexing (OFDM) in the downlink of Long Term Evolution (LTE) and in many other applications. It contains the analysis of different methods, their explanations, areas of implementation, advantages, drawbacks and finally a comparison of the methods has been made. The paper is based on the fact that during OFDM reception, the overlapping frequencies interfere due to various reasons and different methods have to be applied to avoid interference among the frequencies for a proper reception at the receiver.
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Comparative Study of Navigation Methods for Unmanned Vehicles in a GPS-Denied Environment
Статья научная
In this era of increasing technological advancement, where mankind is pushing the frontiers of exploration, systems are required to be increasingly autonomous and intelligent in order to work efficiently, and to provide optimum results. Unmanned vehicles generally use GPS to find their position in an environment and navigate. In this paper, we have studied and analysed two different algorithms used for navigating in a GPS denied environment, which is a more common scenario than navigating in a GPS-enabled environment. The SLAM algorithm generates a map of its environment by estimation and mapping, while the LIDAR maps its environment using pulses of a short wavelength. Both of them can be used for widely varying applications, and current researches in these fields are crucial in the development of autonomous systems.
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Compose Real-world Service With Context
Статья научная
Advances in the areas of smart embedded devices, computing and networking are leading to the emergence of the Internet of Things (IoT) composed of millions of heterogeneous devices. These devices will be interconnected, providing and consuming information available on the network and cooperate. As the improvement of the performance of industrial processes, the service-oriented approach can be adopted for smart embedded devices. Each device can offer its functionality as services. In such infrastructures, traditional web service compositions can not adapt to the dynamic environment for the Internet of Things. In this paper, we propose an approach to compose services with context. It can not only adapt to dynamic environment for the Internet of Things, but also satisfy the user’s preferences. We first build context ontology to describe the scenario for user. According to context information, the service composition process is presented.
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Статья научная
The solution of the modal equation of a planar optical waveguide is a cumbersome job and usually incident angle of successful modes is determined by a graphical solution. In this research work, we applied two computational intelligence methods: Particle Swarm Optimization (PSO) and Genetic algorithm (GA) in a segment-wise approach to solving the modal equation of the tangent function. The motivation for employing Computational Intelligence (CI) lies in its ability to optimize functions without requiring high-level mathematics or complex statistical models, as opposed to traditional analytical methods. This strategic use of computational intelligence significantly reduces the overall computational cost, more nature inspired and probabilistic, providing an efficient alternative. Particularly for functions with complex solutions, the utilization of computational intelligence or soft computing methods becomes imperative to obtain an approximate solution compared to classical numerical optimization methods like Newton-Raphson, bisection etc. that generally deterministic and aim to find the exact optimal solution. In terms of using probability (a core component of chosen algorithm’s searching mechanism) we can incorporate distributions that will enhance the performance. Therefore, while classical root-finding methods are computationally simpler for isolated cases, the use of PSO and GA is motivated by their global search capability, robustness to initialization, and ease of automation, which are advantageous in generalized or large-scale modal solution frameworks. The outcomes derived from both methods (PSO and GA) are meticulously compared with the results obtained through the traditional graphical solution. We have found accuracy of 99.95% for PSO and 99.87% for GA. Notably, the findings reveal a close correlation between the computational intelligence approaches and the graphical method offering a promising avenue for advancing the field with a more computationally feasible approach.
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Construction of Periodic Complementary Multiphase Sequences Based on Perfect Sequences
Статья научная
This paper provides a construction method of periodic complementary multiphase sequences. The proposed method is based on perfect sequences possessing ideal periodic auto-correlation properties. By interleaving any two different perfect sequences with the same length, a kernel set of periodic complementary sequence with multiphase elements can be generated. Compared with the known periodic complementary binary sequences, the presented periodic complementary multiphase sequences may obtain much more lengths of element sequences, which will assure that the generated sequences can provide a more flexible choice of parameters for communication systems.
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Convergence of MANET in communication among smart devices in IoT
Статья научная
In the next generation network, the physical things will enable to exchange the information among them. Internet of Things (IoT) is an emerging technology that provides facility to connect physical things with the digital world and able to exchange the information. Mobile ad-hoc networks (MANET) is consistently self-designing, framework less system of smart devices associated with each other remotely. Every smart device is enabled to change their locations using the mobility feature of MANET. These devices are also able to act as a bridge to exchange information between devices. MANET in the IoT becomes more attractive with its important approach in the communication among smart objects because MANET has a special feature that can create a network by own self or can connect with another huge network. In this research, the authors propose a solution that describes the convergence of MANET in the IoT. The results found in this paper have been tested and implemented using different seniors.
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