9 research outputs found
Enhanced Bandwidth of Band Pass Filter Using a Defected Microstrip Structure for Wideband Applications
In this paper, the bandwidth enhancement of bandpass filter (BPF) is proposed by utilizing defected microstrip structure (DMS). The initial micro strip BPF which is designed to have the bandwidth 1GHz with the center frequency of 3.5GHz is deployed on FR4 Epoxy dielectric substrate with overall size and thickness of 14mm x 24mm and 1.6mm, respectively. The proposed filter consists of two parallel coupled lines centred by ring-shaped, to enhance the bandwidth response, an attempt is carried out by applying DMS on the ligne center with a ring-shaped of initial filter. Here, the proposed DMS is constructed of the arrowhead dumbbell. Some parametrical studies to the DMS such as changing to obtain the optimum geometry of DMS with the desired bandwidth response. From the characterization result, it shows that the utilization of DMS on to the microstrip ligne of filter has widened 3dB bandwidth response up to 1.8GHz ranges from 2.55GHz to 4.35GHz yielding an enhanced wideband response for various wideband wireless applications
Analysis on the effects of the human body on the performance of wearable textile antenna in substrate integrated waveguide technology
© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.A wearable textile circular ring slot antenna based on a substrate integrated waveguide cavity is presented. In this paper, the focus is on studying and understanding the technical behavior of the SIW textile antenna when located near the human body. Thus, based on the electrical properties of conductive material and the dielectric characteristics of the Felt substrate, a 5.5GHz electro-textile antenna was designed. The proposed antennas are simulated in free space, while the performance of antenna is investigated for on-body condition. The simulated impedance bandwidths of the proposed antenna in free space and on phantom are 120MHz and 110MHz at 5.5GHz respectively. The efficiencies of the antenna at 5.5GHz are 95.8% in free space, and 91.6% on phantom, respectively, meanwhile the gains of that are 8.64dB and 9.35dB, respectively.Peer ReviewedPostprint (author's final draft
A Comparison Study of PAPR Reduction in OFDM Systems Based on Swarm Intelligence Algorithms
Optimization algorithms have been one of the most important research topics in Computational Intelligence Community. They are widely utilized mathematical functions that solve optimization problems in a variety of purposes via the maximization or minimization of a function. The swarm intelligence (SI) optimization algorithms are an active branch of Evolutionary Computation, they are increasingly becoming one of the hottest and most important paradigms, several algorithms were proposed for tackling optimization problems. The most respected and popular SI algorithms are Ant colony optimization (ACO) and particle swarm optimization (PSO). Fireworks Algorithm (FWA) is a novel swarm intelligence algorithm, which seems effective at finding a good enough solution of a complex optimization problem. In this chapter we proposed a comparison study to reduce the high PAPR (Peak-to-Average Power Ratio) in OFDM systems based on the swarm intelligence algorithms like simulated annealing (SA), particle swarm optimization (PSO), fireworks algorithm (FWA), and genetic algorithm (GA). It turns out from the results that some algorithms find a good enough solutions and clearly outperform the others candidates in both convergence speed and global solution accuracy
Multiband Planar Inverted-F Antenna with Independent Operating Bands Control for Mobile Handset Applications
A new compact multiband PIFA (Planar Inverted-F Antenna) for mobile handset is proposed in this article. The proposed PIFA has a simple geometry with four slots integrated in the radiating patch and ground plane. The PIFA occupies a small volume of 51 × 14 × 7.2 mm3 and is placed on the top portion of mobile phone. The optimized PIFA is worked in the 790 MHz band (737–831 MHz), the 1870 MHz band (1794–1977 MHz), the 2550 MHz band (2507–2615 MHz), and the 3400 MHz band (3341–3545 MHz), to cover LTE700, LTE800, DCS1800, PCS1900, LTE1800, LTE1900, LTE2500, and WIMAX3400 bands. Each of the four operating bands can be controlled independently by the variation of a single parameter of the proposed design, with a wide control range. An omnidirectional radiation pattern to each resonant frequency is obtained with a maximum gain of 2.15 dBi at 790 MHz, 3.99 dBi at 1870 MHz, 4.57 dBi at 2550 MHz, and 6.43 dBi at 3400 MHz. The proposed PIFA is studied in the free space and in the presence of other mobile phone components such as the battery, LCD (liquid crystal display), camera, microphone, speaker, buttons, and a plastic housing. The distribution of specific absorption rate for both European and American standards for each operating band and at various distances between the antenna and the human head is also studied
A review of flexible wearable antenna sensors: design, fabrication methods, and applications
This review paper summarizes various approaches developed in the literature for antenna sensors with an emphasis on flexible solutions. The survey helps to recognize the limitations and advantages of this technology. Furthermore, it offers an overview of the main points for the development and design of flexible antenna sensors from the selection of the materials to the framing of the antenna including the different scenario applications. With regard to wearable antenna sensors deployment, a review of the textile materials that have been employed is also presented. Several examples related to human body applications of flexible antenna sensors such as the detection of NaCl and sugar solutions, blood and bodily variables such as temperature, strain, and finger postures are also presented. Future investigation directions and research challenges are proposed.This work was supported by the Spanish Government-MINECO under Projects TEC2016-79465-R.Peer ReviewedPostprint (published version
PAPR Reduction Using Fireworks Search Optimization Algorithm in MIMO-OFDM Systems
The transceiver combination technology, of orthogonal frequency division multiplexing (OFDM) with multiple-input multiple-output (MIMO), provides a viable alternative to enhance the quality of service and simultaneously to achieve high spectral efficiency and data rate for wireless mobile communication systems. However, the high peak-to-average power ratio (PAPR) is the main concern that should be taken into consideration in the MIMO-OFDM system. Partial transmit sequences (PTSs) is a promising scheme and straightforward method, able to achieve an effective PAPR reduction performance, but it requires an exhaustive search to find the optimum phase factors, which causes high computational complexity increased with the number of subblocks. In this paper, a reduced computational complexity PTS scheme is proposed, based on a novel swarm intelligence algorithm, called fireworks algorithm (FWA). Simulation results confirmed the adequacy and the effectiveness of the proposed method which can effectively reduce the computation complexity while keeping good PAPR reduction. Moreover, it turns out from the results that the proposed PTS scheme-based FWA clearly outperforms the hottest and most important evolutionary algorithm in the literature like simulated annealing (SA), particle swarm optimization (PSO), and genetic algorithm (GA)
A novel ultra-wide band wearable antenna under different bending conditions for electronic-textile applications
This is an Accepted Manuscript of an article published by Taylor & Francis Group in The Journal of The Textile Institute on 5 May 2020, available online at: http://www.tandfonline.com/10.1080/00405000.2020.1762326This paper is devoted to a novel textile ultra-wideband (UWB) antenna for wearable applications. The antenna is designed and implemented on a felt textile substrate with attractive features such as a flexible full embroidered topology and a low dielectric loss. In this study, the UWB antenna is evaluated through the reflection coefficient (S11), gain, efficiency and effects of bending. The UWB operation of this compact antenna varies from 3.1GHz to 11.3 GHz implying a fractional bandwidth of 114%, in which the efficiency is over 60% and the realized gain reaches 4dB.This work was supported by the Spanish Government MINECO under Project TEC2016-79465-R and the Erasmus + project National Agencies and the European Commission under grant Erasmus + KA107.Peer Reviewe