scholarly journals Investigation of the method of improving the interference protection of axisymmetric antennas in the anterior semispace

2019 ◽  
Vol 27 (1) ◽  
pp. 89-94
Author(s):  
V. I. Magro ◽  
V. M. Morozov
Keyword(s):  
Focal Point ◽  
Antenna System ◽  
Geometric Optics ◽  
System A ◽  
Working Frequency ◽  
Axis Of Symmetry ◽  
The Difference ◽  
Frequency Changes ◽  
Diffraction Effects ◽  
Focusing Properties

The method of improving the interference protection of axisymmetric antennas is considered. An experimental study of the focusing properties of a zonal antenna is carried out in this work. Such a zonal antenna acts as a shading screen and is located in the aperture of an axisymmetric antenna. The combination of a shading screen with an axisymmetric antenna can significantly reduce the level of side lobes in the anterior semi-space, and as a result, significantly improve the immunity of the antenna system. A zonal antenna for 40 GHz frequency is manufactured. The field distribution along the axis of symmetry for different numbers of rings in the antenna is experimentally investigated. The number of rings varied from 1 to 5. The focusing properties of the zonal antenna are studied at the change of operating frequency. The position of the focus is investigated when the working frequency changes in relation to the calculated frequency. It is established that the experimentally found focal point does not coincide with the focal point found by geometric optics. For a zonal antenna with three rings, the difference between the experimentally found focus and the focus found by the law of geometric optics is 0.1%. The distribution of the field in planes perpendicular to the focal line is investigated. It is established that an increase in the number of rings in a zonal antenna to more than five leads to diffraction effects which impair the focusing properties of the zonal antenna. At the same time there is a "deliquescence" of the wave beam in the focus. These studies allow us to determine the boundaries of the working frequency of a complex antenna system.

Timing Acquisition Based on Cooperation Verification of Distributed Receive Antennas in Linear Cell

2013 ◽  
Vol 340 ◽  
pp. 551-556
Author(s):  
Chao Jin Qing ◽  
Jin Cheng Wei ◽  
You Xi Tang ◽  
Jin Lian Liu
Keyword(s):  
Time Delays ◽  
Antenna System ◽  
Distributed Antenna System ◽  
Timing Acquisition ◽  
Verification Method ◽  
Threshold Detection ◽  
System A ◽  
Distributed Antenna ◽  
The Difference ◽  
Linear Cell

To improve the probability of correct acquisition for distributed antenna system, a cooperation verification method of distributed antennas is proposed. In the flat Rayleigh channels of linear cell, the difference of time-delays is firstly exploited to compose a pre-condition for cooperation. Then, the timing acquisition based on threshold detection is performed at each distributed antenna. For eliminating part of acquisition errors, the cooperation verification is introduced into the timing acquisition according to pre-condition. Analysis and simulation results verify the correctness of the proposed method.

Sub-6 GHz Band Massive MIMO Antenna System for Variable Deployment Scenarios in 5G Base Stations

2021 ◽  
Author(s):  
Darwin R ◽  
Sampath P
Keyword(s):  
Massive Mimo ◽  
Mimo System ◽  
Ground Plane ◽  
Antenna System ◽  
Base Stations ◽  
Base Layer ◽  
Mimo Antenna ◽  
System A ◽  
Length Width ◽  
Working Frequency

Abstract A compact massive MIMO antenna system with 1x4 (sector) subarray setup working at sub-6 GHz range for 5G base stations has been planned and broke down in different configurations(rectangular, triangular and hexagonal). The limit of a system can be expanded by more than 10 times whereas the energy efficiency can be expanded 100 times utilizing a Massive MIMO system. A limit of 5 sectors has been utilized with every sector containing 1x4 subarray components. Every sector comprises of three layers, in which 1x4 patches is situated on its top layer though it's taking care of organization and ground plane has been set in the base layer and the centre layer individually. The whole system can work in two modes, singular port activity andmassive MIMO exhibit activity with shaft guiding abilities. The deliberate data transmission of the framework is 140 MHz that covers the frequencies from 3.36 GHz to 3.50 GHz in sub-6 GHz band. The general component of a unit subarray regarding length, width and tallness was 280.5 x 56.1 x 2 mm3. The gain of an individual port is discovered to be 12.95 dBi and the general addition of a single panel with 5 sectors arranged in rectangular structure is 19.73 dBi. Mutual couplingamong all the ports has been kept not exactly - 16 dB. The working frequency of the radio antenna array system is picked in the scope of 3.3 GHz to 3.8 GHz as this band has been assigned and focused across the globe to empower 5G in Sub-6 GHz band.

scholarly journals Generational Differences in Support and Care of Individuals Diagnosed With Severe Mental Illness

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 94-94
Author(s):  
Deborah Finkel ◽  
Per Bulöw ◽  
Pia Bulöw ◽  
Monika Wilińska ◽  
Cristina Joy Torgé ◽  
...  
Keyword(s):  
Social Support ◽  
Mental Illness ◽  
Severe Mental Illness ◽  
Social Services ◽  
Generational Differences ◽  
System A ◽  
Care Systems ◽  
The Difference ◽  
Changes Over Time ◽  
Age Range

Abstract As part of the process of de-institutionalizing the Swedish mental health care system, a reform was implemented in 1995 moving responsibility for social support for people with severe mental illness (SMI) from the county to social services in the municipalities. In many ways, older people with SMI were neglected in this changing landscape of psychiatric care. To investigate possible generational differences in support experiences, two nonoverlapping cohorts were created from surveys conducted every fifth year between 1996 and 2011 in one middle-sized municipality in the south of Sweden, aiming to detect the needs for social support. Cohort 1 includes everyone detected at the 1996 survey aged 65 and 79 years (N = 92). Cohort 2 includes individuals first detected at the 2011 survey who were aged 65 to 79 (N = 104). Results indicates significant differences between the two cohorts in diagnosis, reflecting changes over time in diagnostic tendencies. Cohort 1 was on average 10 years older than Cohort 2, even within the restricted age range. After correcting for age, there were no differences between the two cohorts in education, functioning (CAN and GAF), or marital status. Although Cohort 1 experienced more days of institutionalization than Cohort 2 (median = 424.5 days vs. 382 days), the difference was not statistically significant. Cohort 2 had significantly higher additional subsidies and disposable income, as well as significantly higher income from other sources after retirement. Results indicate the changing demands that older adults with SMI will place on care systems.

Markedness and Perspective in the Interpretation of the Active and Passive Voice

1974 ◽  
Vol 26 (2) ◽  
pp. 189-195 ◽  
Author(s):  
Irene Klenbort ◽  
Moshe Anisfeld
Keyword(s):  
Information Content ◽  
Focal Point ◽  
The Other ◽  
Clear Pattern ◽  
Passive Voice ◽  
Other Hand ◽  
Logical Subject ◽  
The Difference

The subjects were presented with active and passive sentences. For each sentence, they had to choose between two alternative implications. The pattern of choices indicates that in the passive the logical subject was interpreted by the subjects as the focal point of the information asserted by the sentence and as the carrier of overall responsibility for the sentential proposition. In contrast to the passive, there was no clear pattern of preferences for the active. The difference between the two voices was attributed to their markedness asymmetry, the passive being marked and the active unmarked. It is concluded that the active offers a neutral structure for conveying information; a structure available for use when one does not want to superimpose on the information content any stylistic or connotational implications. The passive, on the other hand, suggests special connotations in addition to the basic message.

scholarly journals Slovene-English Contrastive Phraseology: Lexical Collocations

2010 ◽  
Vol 7 (2) ◽  
pp. 57-73
Author(s):  
Primož Jurko
Keyword(s):  
English Language ◽  
Focal Point ◽  
Systematic Classification ◽  
Lexical Collocations ◽  
The Difference ◽  
Translation Errors ◽  
Language Pair

Phraseology is seen as one of the key elements and arguably the most productive part of any language. %e paper is focused on collocations and separates them from other phraseological units, such as idioms or compounds. Highlighting the difference between a monolingual and a bilingual (i.e. contrastive) approach to collocation, the article presents two distinct classes of collocations: grammatical and lexical. %e latter, treated contrastively, represent the focal point of the paper, since they are an unending source of translation errors to both students of translation and professional translators. %e author introduces a methodology of systematic classification of lexical collocations applied on the Slovene-English language pair and based on structural (lexical congruence) and semantic (translational predictability) criteria.

scholarly journals 4 × 4 MIMO Antenna System for Smart Eyewear in Wi-Fi 5G and Wi-Fi 6e Wireless Communication Applications

Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 2936
Author(s):  
Ming-An Chung ◽  
Cheng-Wei Hsiao ◽  
Chih-Wei Yang ◽  
Bing-Ruei Chuang
Keyword(s):  
Ground Plane ◽  
Multiple Input Multiple Output ◽  
Antenna System ◽  
Slot Antenna ◽  
Actual Measurement ◽  
Antenna Efficiency ◽  
Mimo Antenna ◽  
Measurement Results ◽  
Working Frequency ◽  
Peak Gain

This paper proposes a small-slot antenna system (50 mm × 9 mm × 2.7 mm) for 4 × 4 multiple-input multiple-output (MIMO) on smart glasses devices. The antenna is set on the plastic temple, and the inverted F antenna radiates through the slot in the ground plane of the sputtered copper layer outside the temple. Two symmetrical antennas and slots on the same temple and series capacitive elements enhance the isolation between the two antenna ports. When both temples are equipped with the proposed antennas, 4 × 4 MIMO transmission can be achieved. The antenna substrate is made of polycarbonate (PC), and its thickness is 2.7 mm εr=2.85, tanδ=0.0092. According to the actual measurement results, this antenna has two working frequency bands when the reflection coefficient is lower than −10dB, its working frequency bandwidth at 4.58–5.72 GHz and 6.38–7.0 GHz. The proposed antenna has a peak gain of 4.3 dBi and antenna efficiency of 85.69% at 5.14 GHz. In addition, it also can obtain a peak gain of 3.3 dBi and antenna efficiency of 82.78% at 6.8 GHz. The measurement results show that this antenna has good performance, allowing future smart eyewear devices to be applied to Wi-Fi 5G (5.18–5.85 GHz) and Wi-Fi 6e (5.925–7.125 GHz).

scholarly journals On the self-induction of electric currents in a thin anchor-ring

1912 ◽  
Vol 86 (590) ◽  
pp. 562-571 ◽  
Keyword(s):  
Cross Section ◽  
Circular Cross Section ◽  
The Self ◽  
Electric Currents ◽  
Fourth Term ◽  
Starting Point ◽  
Axis Of Symmetry ◽  
The Difference ◽  
Circular Axis ◽  
Mutual Induction

In their useful compendium of "Formulæ and Tables for the Calculation of Mutual and Self-Inductance," Rosa And Cohen remark upon a small discrepancy in the formulæ given by myself and by M. Wien for the self-induction of a coil of circular cross-section over which the current is uniformly distributed . With omission of n , representative of the number of windings, my formula was L = 4 πa [ log 8 a / ρ - 7/4 + ρ 2 /8 a 2 (log 8 a / ρ + 1/3) ], (1) where ρ is the radius of the section and a that of the circular axis. The first two terms were given long before by Kirchhoff. In place of the fourth term within the bracket, viz., +1/24 ρ 2 / a 2 , Wien found -·0083 ρ 2 / a 2 . In either case a correction would be necessary in practice to take account of the space occupied by the insulation. Without, so far as I see, giving a reason, Rosa and Cohen express a preference for Wien's number. The difference is of no great importance, but I have thought it worth while to repeat the calculation and I obtain the same result as in 1881. A confirmation after 30 years, and without reference to notes, is perhaps almost as good as if it were independent. I propose to exhibit the main steps of the calculation and to make extension to some related problems. The starting point is the expression given by Maxwell for the mutual induction M between two neighbouring co-axial circuits. For the present purpose this requires transformation, so as to express the inductance in terms of the situation of the elementary circuits relatively to the circular axis. In the figure, O is the centre of the circular axis, A the centre of a section B through the axis of symmetry, and the position of any point P of the section is given by polar co-ordinates relatively to A, viz.

Bicarbonate-carbon dioxide buffer system: a determinant of the mitochondrial pH gradient

1984 ◽  
Vol 247 (3) ◽  
pp. F440-F446 ◽  
Author(s):  
D. P. Simpson ◽  
S. R. Hager
Keyword(s):  
Carbon Dioxide ◽  
Renal Cortex ◽  
Ph Gradient ◽  
Buffer System ◽  
Acid Base ◽  
Bicarbonate Buffer ◽  
Inner Membrane ◽  
System A ◽  
Intact Kidney ◽  
The Difference

The influence of the bicarbonate-carbon dioxide buffer system on the pH gradient (delta pH) across the inner membrane of mitochondria from rabbit renal cortex was studied with and without phosphate in the medium. delta pH with bicarbonate buffer or phosphate in the medium was greater at low than at high medium pH so that the difference (delta delta pH) between delta pH at pH 7.1 and at 7.6 was positive. Varying the concentration of phosphate from 0 to 10 mM had little effect on delta delta pH produced by bicarbonate buffer. Inhibition of the phosphate-hydroxyl carrier with N-ethylmaleimide abolished delta delta pH when phosphate was present in non-bicarbonate-containing media. With bicarbonate buffer present, N-ethylmaleimide increased delta delta pH. Similar effects were observed in mitochondria from liver and heart as well as from kidney. The effects of the bicarbonate buffer system on delta pH may result either from an inner membrane permeable to carbon dioxide but not to bicarbonate ion or from an active carrier for bicarbonate ion in the inner membrane. In intact kidney cells, the influence of the bicarbonate buffer system on delta pH may provide a mechanism for regulating substrate metabolism in response to acid-base changes. It may also serve in many organs to reduce fluctuations in matrix pH when alterations in cytoplasmic pH occur.

Noise Analysis and Filtering for Laser Active Imaging System

2013 ◽  
Vol 475-476 ◽  
pp. 282-286
Author(s):  
Tao Sun
Keyword(s):  
Imaging System ◽  
Noise Analysis ◽  
Speckle Noise ◽  
Recognition System ◽  
Denoising Method ◽  
Edge Information ◽  
System A ◽  
Active Imaging ◽  
The Difference ◽  
Contour Curvature

In order to deal with the contradiction between suppressing speckle noise and reserving details in laser active imaging recognition system, a denoising method based on contour curvature is proposed. Due to the contour curvature, the pixels in the image are divided into different classes, which contain different amount of information. The filter parameters are different for each class. Firstly, the origin image is smoothed using wavelet soft thresholding, then the contours are extracted by Morphological edge detection operator. Due to the difference of contour curvature, the pixels are labeled with point of strong signal, point of weak signal or point of no signal. Pixels with different labels are filtered by Lee filter of different step width. Experiment result indicates that compared with classical Lee filter, the proposed method performs better in filtering and keeping edge information.

Large Stroke Series Compliant Mechanism

2012 ◽  
Vol 490-495 ◽  
pp. 1104-1108 ◽  
Author(s):  
Ming Cai Shan ◽  
Wei Ming Wang ◽  
Shu Yuan Ma ◽  
Shuang Liu
Keyword(s):  
Theoretical Model ◽  
Maximum Stress ◽  
Compliant Mechanism ◽  
Critical Parameters ◽  
Element Analysis ◽  
Flexure Hinges ◽  
Body Model ◽  
System A ◽  
Rigid Body Model ◽  
The Difference

To increase the stroke of precision positioning system, a novel series compliant mechanism is presented which is based on elliptical flexure hinges. Pseudo-rigid-body model and energy method are applied to establish the theoretical model of stiffness and maximum stress, which are critical parameters for the large stroke compliant mechanism. The relationships are analyzed between geometric parameters of the series complaint mechanism, stiffness and maximum stress. According that, the series compliant mechanism is designed with the stroke more than 5mm and stiffness less than 3.2N/mm. The difference is less than 5% between the results of finite element analysis and theoretical model computation, which proves the correctness of the application design.

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