DC/RF and Statistic Modeling of Four Terminal InGap/GaAs Bifet for wireless application

Author(s):  
C. Wei ◽  
A. Metzger ◽  
Y. Zhu ◽  
C. Cismaru ◽  
A. Klimashov ◽  
...  
2018 ◽  
Vol 3 (1) ◽  
pp. 35 ◽  
Author(s):  
Cihat Şeker ◽  
Turgut Ozturk ◽  
Muhammet Tahir Güneşer

In this proposed paper, a single band microstrip patch antenna for fifth generation (5G) wireless application was presented. 28, 38, 60 and 73 GHz frequency bands have been allocated for 5G mobile communications by International Telecommunications Union (ITU). In this paper, we proposed an antenna, which is suitable for the millimeter wave frequency. The single band antenna consists of new slot loaded on the radiating patch with the 50 ohms microstrip line feeding used. This single band antenna was simulated on a FR4 dielectric substrate have relative permittivity 4.4, loss tangent 0.02, and height 1.6 mm. The antenna was simulated by Electromagnetic simulation, computer software technology High Frequency Structural Simulator. And simulated result on return loss, VSWR, radiation pattern and 3D gain was presented. The parameters of the results well coherent and proved the literature for millimeter wave 5G wireless application at 38 GHz.


2021 ◽  
Vol 2021 (5) ◽  
pp. 40-47
Author(s):  
Elena Rozhkova

The purpose of this work is the assessment and forecasting of freight car technical state at life stages. The scientific novelty consists in the definition of car operating run-up to the first failure and between failures, and also in the definition of car life to considerable repair fulfillment from the operating run between failures and development of a graphical model of freight car reliability. As a result of the statistic modeling of gondola car operating runs up to the first failure it is defined that the given random value conforms to a normal distribution law, the first car setoff in TOR due to wear failure takes place at the operating run of 85,000 km. Besides the operating run-up to the first failure there was defined an operating run-up between failures. It is proved that the operating run-up between failures conforms to the exponential law of distribution, the mathematical expectation of which is 13,000 km. The results of investigations mentioned above formed the basis of the graphical model of car reliability. An inter-repair service life of a car can be represented as a sum of the following operating run-ups: operating run-ups to the first failure, the product of operating run-ups between failures and the number of failures and a residual operating run-up (from the utmost current repair to the nearest scheduled repair). On the basis of the mentioned it is expedient to consider a technology for the realization of an enlarged repair with the purpose of the repetition exclusion in car setoffs during the inter-repair term. On the basis of the simulator there is obtained the dependence of the frequency of car enlarged current repair fulfillment depending on average operating run-up between failures. At present an enlarged current repair must be carried out only for gondola cars in the planned order after having reached 80,000 km. The repair mentioned can be carried out both under depot conditions, and under conditions of repair workshops. The advantage of such a system of repair consists in the increase car work reliability during the inter-repair term.


2018 ◽  
Vol 218 ◽  
pp. 03015 ◽  
Author(s):  
Ahmad Firdausi ◽  
Galang Hakim ◽  
Mudrik Alaydrus

One of the technologies that has wireless application nowadays was 5G mobile communication.This paper presents the designing of a Tri-band microstrip antenna for targeting 5G broadband communications, This element antenna has 3x3 rectangular patches with feeding line structures are branched. With the use of double feeding proximity coupling structure, we intend to maximize antenna bandwidth, therefore the antenna cover range tri-band frequency from 40 GHz to 70 GHz. The reflection factor comparation between simulation and measurement has a minimum with respective frequency at 45.3 GHz, 57 GHz, and 66 GHz. The total measurement bandwith 11.5 Ghz. With this combination tecnique, the proposed antenna is a promising candidate for 5G communication systems.


ReCALL ◽  
2008 ◽  
Vol 20 (3) ◽  
pp. 331-347 ◽  
Author(s):  
Ki Chune Nah ◽  
Peter White ◽  
Roland Sussex

AbstractInterest in the use of a mobile phone to access the Internet for learning English in general, and listening skills in particular, has been increasing in Korea over the last few years. However, there has been only a small number of studies on this topic in Korea. The present paper investigates the potential of using a mobile phone to browse wireless application protocol (WAP) sites for the purpose of learning listening skills. The study focuses specifically on the attitudes of language learners toward using a mobile phone for this purpose. The study is based on input, interaction, output and sociocultural theories, as well as on collaborative, learner-centred, constructivist and task-based learning approaches. An experiment was carried out with a group of undergraduate students who had enrolled in a required intermediate English as a Foreign Language (EFL) listening course at a Korean university. A WAP site was designed and used as the instrument for the experiment. This study found that the language learners expressed positive attitudes towards the use of the WAP site. It also found that the WAP site can be effective for learning listening skills and for student-centred and collaborative learning. Based on the findings, it is clear that WAP sites can be effective for learning listening skills, since they can enhance opportunities to learn language skills, and encourage language learners to participate actively in the learning process.


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