scholarly journals Radiating Slot in the Coaxial Cable Shield: Measurement Based Characterization

2015 ◽  
Vol 11 (3) ◽  
pp. 136
Author(s):  
Antonio Šarolić ◽  
Zlatko Živković ◽  
Damir Senić ◽  
Niko Ištuk

The paper presents the comprehensive experimental study of radiation characteristics of a single slot in a coaxial cable shield. The slot was realized in four different embodiments, which varied by slot orientation and length. Three orthogonal polarizations of radiated electric field were analyzed along the axis perpendicular to cable, broadside to the slot, in a broadband frequency range (80-1000 MHz). The analysis was based on thorough measurements of the coupling loss, which is the common parameter for the leaky cable characterization. The obtained results showed that the electric field component longitudinal to the cable axis considerably dominates over other two orthogonal components, for all four slot types. Doubling the length of the slot caused a ca. 20 dB increase of the radiated field. Different slot orientations, having the same length in the cross-section projection, yielded approximately equal field strengths. The results of this experimental study clearly and visibly demonstrate the radiating slot field dependence on polarization and slot geometry in a wide frequency range. Thus they are useful for planning of wireless communication systems based on radiating cables, as well as for understanding polarization related issues in such systems.

2021 ◽  
Author(s):  
Vladimir Sergeevich Milyutin ◽  
Eugeniy Vasilevich Rogozhnikov ◽  
Kirill Petrovskiy ◽  
Dmitriy Pokamestov ◽  
Edgar Dmitriyev ◽  
...  

Abstract Frequency synchronization is a necessary operation for all wireless communication systems. Due to the wide frequency range defined for 5G NR systems, this procedure becomes critical. To ensure high transmission rates and the use of high-order modulation, up to 256 QAM for 5G communication systems, it is necessary to ensure high frequency synchronization accuracy. In this article, we have reviewed various approaches to implementing frequency synchronization and proposed, in our opinion, the most effective method for correcting the frequency shift of the signal.


Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 477
Author(s):  
Warsha Balani ◽  
Mrinal Sarvagya ◽  
Ajit Samasgikar ◽  
Tanweer Ali ◽  
Pradeep Kumar

In this article, a compact concentric structured monopole patch antenna for super wideband (SWB) application is proposed and investigated. The essential characteristics of the designed antenna are: (i) to attain super-wide bandwidth characteristics, the proposed antenna is emerged from a traditional circular monopole antenna and has obtained an impedance bandwidth of 38.9:1 (ii) another important characteristic of the presented antenna is its larger bandwidth dimension ratio (BDR) value of 6596 that is accomplished by augmenting the electrical length of the patch. The electrical dimension of the proposed antenna is 0.18λ×0.16λ (λ corresponds to the lower end operating frequency). The designed antenna achieves a frequency range from 1.22 to 47.5 GHz with a fractional bandwidth of 190% and exhibiting S11 < −10 dB in simulation. For validating the simulated outcomes, the antenna model is fabricated and measured. Good conformity is established between measured and simulated results. Measured frequency ranges from 1.25 to 40 GHz with a fractional bandwidth of 188%, BDR of 6523 and S11 < −10 dB. Even though the presented antenna operates properly over the frequency range from 1.22 to 47.5 GHz, the results of the experiment are measured till 40 GHz because of the high-frequency constraint of the existing Vector Network Analyzer (VNA). The designed SWB antenna has the benefit of good gain, concise dimension, and wide bandwidth above the formerly reported antenna structures. Simulated gain varies from 0.5 to 10.3 dBi and measured gain varies from 0.2 to 9.7 dBi. Frequency domain, as well as time-domain characterization, has been realized to guide the relevance of the proposed antenna in SWB wireless applications. Furthermore, an equivalent circuit model of the proposed antenna is developed, and the response of the circuit is obtained. The presented antenna can be employed in L, S, C, X, Ka, K, Ku, and Q band wireless communication systems.


2021 ◽  
Vol 42 (4) ◽  
pp. 357-370
Author(s):  
M. A. Salhi ◽  
T. Kleine-Ostmann ◽  
T. Schrader

AbstractIncreasing data rates in wireless communications are accompanied with the need for new unoccupied and unregulated bandwidth in the electromagnetic spectrum. Higher carrier frequencies in the lower THz frequency range might offer the solution for future indoor wireless communication systems with data rates of 100 Gbit/s and beyond that cannot be located elsewhere. In this review, we discuss propagation channel measurements in an extremely broad frequency range from 50 to 325 GHz in selected indoor communication scenarios including kiosk downloading, office room communication, living rooms, and typical industrial environments.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Kai Zhang ◽  
Fangqi Zhang ◽  
Guoxin Zheng ◽  
Lei Cang

With the rapid development of high-mobility wireless communication systems, e.g., high-speed train (HST) and metro wireless communication systems, more and more attention has been paid to the wireless communication technology in tunnel-like scenarios. In this paper, we propose a three-dimensional (3D) nonstationary multiple-input multiple-output (MIMO) channel model with high-mobility wireless communication systems using leaky coaxial cable (LCX) inside a rectangular tunnel over the 1.8 GHz band. Taking into account single-bounce scattering under line-of-sight (LoS) and non-line-of-sight (NLoS) propagations condition, the analytical expressions of the channel impulse response (CIR) and temporal correlation function (T-CF) are derived. In the proposed channel model, it is assumed that a large number of scatterers are randomly distributed on the sidewall of the tunnel and the roof of the tunnel. We analyze the impact of various model parameters, including LCX spacing, time separation, movement velocity of Rx, and K-factor, on the T-CF of the MIMO channel model. For HST, the results of some further studies on the maximum speed of 360 km/h are given. By comparing the T-CF between the dipole MIMO system and the LCX-MIMO system, we can see that the performance of the LCX-MIMO system is better than that of the dipole MIMO system.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Rahmani Faouzi ◽  
Amar Touhami Naima ◽  
BelbachirKchairi Abdelmounaim ◽  
Aknin Noura ◽  
Taher Nihade

This work presents the design and analysis of a beam switching antenna for VANET, Wi-Fi, and WiMAX wireless communication systems. The proposed reconfigurable antenna is powered by a coaxial cable and consists of a circular patch, six fish-shaped radiating elements, and a circular planar ground. The antenna was constructed on a Rogers RT5880 substrate. Its dimensions are as follows: 0.81λ0 × 0.81λ0 × 0.03λ0. It performs six reconfigurable operating states, at the same frequency, by controlling the activation and deactivation of six PIN diodes to change the beam’s direction. A theoretical equivalent circuit model of the antenna is extracted. A progressive analysis of improving the antenna characteristic performances is provided. The bandwidth of the proposed antenna is 9.07% (measured), 9.62% (simulated), and 9.31% (theoretical). The designed antenna has a maximum gain of 9.57 dB for all pattern states and a superior efficiency ratio from 85% to 95% over the operating range (5.54 GHz–6.10 GHz). The proposed reconfigurable antenna is fabricated. Measured, simulated, and theoretical results are given and show good agreement, including reflection coefficient (S11) and radiation patterns.


Author(s):  
Э.П. Шурина ◽  
Д.В. Добролюбова ◽  
Е.И. Штанько

При решении задач электромагнетизма в широком частотном диапазоне в областях с тонкими пластинами, оболочками и экранами численными методами возникает проблема резкого роста сеточной дискретизации вблизи внутренних структур с разномасштабными габаритными размерами. В работе предложена модификация вариационной постановки векторного метода конечных элементов, основанная на снижении размерности модели в окрестности тонких включений, которая позволяет преодолеть эту проблему за счет специфического учета таких структур на уровне вариационной постановки. Так как редуцирование модели обычно приводит к появлению ограничений на область ее применимости, выполнено исследование диапазона допустимых частот, контрастности электрофизических характеристик матрицы и включений, геометрических особенностей внутренней структуры, для которых предложенная модель позволяет получить корректные с точки зрения физики результаты. Purpose. In this paper, we propose a reduced variational formulation for the Helmholtz equation for the electric field, in which thin highly conductive objects are approximated by surfaces with the equivalent surface current density. We conduct a study aimed at defining the range of application for the reduced variational formulation, focusing on highly contrasting thin objects of various geometrical shape and arrangement in a wide frequency range. Methodology. The modelling is performed on unstructured tetrahedral meshes. Since the reduced variational formulation treats thin highly conductive objects as surfaces, no volume mesh is constructed inside of them.We compare the results obtained by the vector FEM using the proposed variational formulation with the results obtained using standard formulation. Findings. Due to the fact that the proposed variational formulation does not require volume meshing of the thin objects, its computational cost is significantly lower. However, the reduced formulation yields correct results in a restricted frequency range. It also imposes some limitations on the minimal contrast and maximal thickness of the thin highly conductive objects. Originality/value. The proposed reduced variational formulation can be applied to simulate the time-harmonic electric field in the media with thin highly conductive inclusions of either regular or chaotic arrangement, as well as thin shielding plates or casings of various geometrical forms.


Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 347 ◽  
Author(s):  
Ke Li ◽  
Tao Dong ◽  
Zhenghuan Xia

This paper presents a multiple-resonance technique that sought to achieve a wide bandwidth for printed wide-slot antennas with fork-shaped stubs. By properly appending an extra fork-shaped stub onto the main fork-shaped stub, the impedance bandwidth was able to be clearly broadened. To validate this technique, two designs where the extra stubs were added at different positions of the main stub were constructed. The measured impedance bandwidths of the proposed antennas reached 148.6% (0.9–6.1 GHz) for S11 < −10 dB, indicating a 17.9% wider bandwidth than that of the normal antenna (0.9–4.3 GHz). Moreover, a stable radiation pattern was observed within the operating frequency range. The proposed antennas were confirmed to be much-improved candidates for applications in various wireless communication systems.


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