scholarly journals Mathematical Modeling of the Electrophysical Properties of a Layered Nanocomposite Based on Silicon with an Ordered Structure

Mathematics ◽  
2021 ◽  
Vol 9 (24) ◽  
pp. 3167
Author(s):  
Sergey Korchagin ◽  
Ekaterina Romanova ◽  
Denis Serdechnyy ◽  
Petr Nikitin ◽  
Vil Baiburin ◽  
...  
Keyword(s):  
Practical Interest ◽  
Electrophysical Properties ◽  
Ordered Structure ◽  
Composite Media ◽  
Frequency Range ◽  
Mobile Objects ◽  
Operating Frequency Range ◽  
Traditional Structure ◽  
Nonlinear Radar ◽  
Frequency Dependences

The authors carried out modeling of the electrophysical properties of composite media. The frequency dependences of the dielectric constant on the type of inclusions in the composite are investigated. On the basis of the nanocomposite considered in the work, based on Si, B, and SiO2, the authors model a reflecting screen, the lattice elements of which have a layered hierarchically constructed structure similar to a fractal formation. The influence of the level of fractality on the optical properties of the object was also investigated, and it was found that the proposed structure makes it possible to increase the operating frequency range of the reflecting screen and the efficiency, in comparison with reflecting screens that have a lattice of traditional structure. The results obtained can be of practical interest for broadband and nonlinear radar devices, localization devices and mobile objects, microelectronics, as well as intelligent applications in the field of information security.

FORMATION OF A SCANNING ANTENNA BASED ON A HALF-WAVE DIPOLE

2021 ◽  
pp. 20-24
Author(s):  
С.М. Фёдоров ◽  
Е.А. Ищенко ◽  
И.А. Баранников ◽  
К.А. Бердников ◽  
В.В. Кузнецова
Keyword(s):  
Short Distance ◽  
Electromagnetic Waves ◽  
High Stability ◽  
Frequency Range ◽  
Current Position ◽  
Form Complex ◽  
Operating Frequency Range ◽  
Half Wave ◽  
Focus Radiation ◽  
Antenna Systems

Рассматривается полуволновый диполь с установленным рефлектором, который позволяет производить сканирование пространства с использованием вращения рефлектора вокруг диполя. Для полученной конструкции производилось моделирование основных параметров, которые показали высокую стабильность при различных положениях рефлектора, постоянное значение коэффициента направленного действия, ширины главного лепестка. Изменение направления излучения совпадает с текущим положением рефлектора. По сравнению с ситуацией, когда у антенны отсутствовал рефлектор, КНД антенны увеличился, так как произошла фокусировка электромагнитных волн. Коэффициент полезного действия и передне-заднее отношение сохраняют высокие значения во всем диапазоне рабочих частот. Применение предложенной конструкции позволяет упростить конструкцию сканирующих антенн, так как для ее реализации требуются лишь полуволновой диполь и плоский рефлектор, установленный на малом расстоянии от источника излучения. В процессе управления характеристиками требуется вращать рефлектор вокруг диполя, при этом диполь остается неподвижным, что позволяет повысить эффективность предложенной конструкции, так как не требуется формировать сложных антенных систем или устанавливать комбинацию из нескольких антенн для фокусировки излучения в одном направлении от источника The article discusses a half-wave dipole with an installed reflector, which allows scanning space using the rotation of the reflector around the dipole. For the resulting structure, we simulated the main parameters, which showed high stability at various positions of the reflector, a constant value of the directivity factor, and the width of the main lobe. The change in the direction of radiation coincides with the current position of the reflector. Compared to the situation when the antenna did not have a reflector, the directivity of the antenna increased since the focusing of electromagnetic waves took place. The efficiency and the front-to-back ratio remain high throughout the entire operating frequency range. The use of the proposed design makes it possible to simplify the design of scanning antennas since the implementation of the proposed design requires only a half-wave dipole and a flat reflector installed at a short distance from the radiation source. In the process of controlling the characteristics, it is required to rotate the reflector around the dipole, while the dipole remains stationary, which makes it possible to increase the efficiency of the proposed design, since it is not required to form complex antenna systems or install a combination of several antennas to focus radiation in one direction from the source

scholarly journals Design of Broadband Compact Canonical Triple-Sleeve Antenna Operating in UHF Band

2021 ◽  
Vol 21 (4) ◽  
pp. 291-298
Author(s):  
Chandana SaiRam ◽  
Damera Vakula ◽  
Mada Chakravarthy
Keyword(s):  
Wireless Communication ◽  
Instantaneous Frequency ◽  
Dipole Antenna ◽  
Frequency Range ◽  
Broadband Antenna ◽  
Operating Frequency Range ◽  
Half Wave ◽  
Measurement Results ◽  
Antenna Configuration ◽  
Good Agreement

In this paper, a novel compact broadband antenna at UHF frequencies is presented with canonical shapes. Hemispherical, conical and cylindrical shapes have all been considered for antenna configuration. The designed antenna provides an instantaneous frequency range from 370 to 5,000 MHz with omnidirectional characteristics. The antenna was simulated in CST Microwave Studio, fabricated and evaluated; the results are presented. The simulated and measurement results are in good agreement. The antenna has voltage standing wave ratio (VSWR) ≤ 1.9:1 in 400–570 MHz, 2,530–3,740 MHz and 4,180–4,620 MHz; it has VSWR ≤ 3:1 over the operating frequency range 370–5,000 MHz and the measured gain varies from -0.6 to 4.5 dBi over the frequency band. The concept of canonical-shaped antenna elements and the incorporation of triple sleeves resulted in a reduction of the length of the antenna by 62% compared to the length of a half-wave dipole antenna designed at the lowest frequency. The antenna can be used for trans-receiving applications in wireless communication.

scholarly journals Studying of dielectric spectra of YCu0.15Mn0.85O3 solid solution with the use of complex conductivity

2021 ◽  
pp. 2160013
Author(s):  
A. V. Nazarenko ◽  
A. V. Pavlenko ◽  
Y. I. Yurasov
Keyword(s):  
Solid Solution ◽  
Electrical Conductivity ◽  
Model Description ◽  
Complex Conductivity ◽  
Electrophysical Properties ◽  
Approximation Model ◽  
Frequency Range ◽  
Dielectric Parameters ◽  
Frequency Behavior ◽  
Complex Electrical Conductivity

This work presents the results of studying the electrophysical properties of the YCu[Formula: see text]Mn[Formula: see text]O3 solid solution in the range of temperatures of [Formula: see text] = 26–400[Formula: see text]C and frequency range of [Formula: see text] = 102–105 Hz. A model description of the revealed dispersion of dielectric parameters in the material is made. The nonclassical modified Havriliak–Negami model written for complex electrical conductivity was used as an approximation model. It is shown that the application of this model almost exactly describes the frequency behavior of the dielectric constant [Formula: see text]/[Formula: see text], the dielectric loss tangent tg[Formula: see text] as well as the real and imaginary parts of complex conductivity [Formula: see text] and [Formula: see text]. The results of this work are an important step in identifying the opportunities and understanding the applications of this model.

scholarly journals A Cylindrical Wideband Conformal Fractal Antenna for GPS Application

2017 ◽  
Vol 6 (3) ◽  
pp. 64
Author(s):  
R. Sahoo ◽  
D. Vakula
Keyword(s):  
Conformal Geometry ◽  
Ground Plane ◽  
Antenna Design ◽  
Fractal Antenna ◽  
Frequency Range ◽  
Bandwidth Enhancement ◽  
Conformal Antenna ◽  
Operating Frequency Range ◽  
Definition Of ◽  
Good Agreement

In this paper, a novel wideband conformal fractal antenna is proposed for GPS application. The concepts of fractal and partial ground are used in conformal antenna design for miniaturization and bandwidth enhancement. It comprises of Minkowski fractal patch on a substrate of Rogers RT/duroid 5880 with permittivity 2.2 and thickness of 0.787mm with microstrip inset feed. The proposed conformal antenna has a patch dimension about 0.39λmm×0.39λmm, and partial ground plane size is 29mm×90mm.The proposed antenna is simulated, fabricated and measured for both planar and conformal geometry, with good agreement between measurements and simulations. The size of the fractal patch is reduced approximately by 32% as compared with conventional patch. It is observed that the conformal antenna exhibits a fractional bandwidth(for the definition of -10dB) of 43.72% operating from 1.09 to 1.7GHz, which is useful for L1(1.56-1.58GHz), L2(1.21-1.23GHz), L3(1.37-1.39GHz), L4(1.36-1.38GHz), and L5(1.16-1.18 GHz) in GPS and Galileo frequencies: E=1589.742MHz(4MHzbandwidth), E2=1561. 098MHz(4MHzbandwidth), E5a=1176.45MHz(=L5),E5b= 1207.14MHz, and E6=1278.75MHz(40MHz bandwidth). The radiation pattern exhibits an omnidirectional pattern, and gain of proposed antenna is 2.3dBi to 3.5dBi within operating frequency range.

STUDY OF PHASED ARRAYS OF SLOTTED WAVEGUIDE ANTENNAS WITH DIELECTRIC FILLING

2021 ◽  
pp. 42-47
Author(s):  
A. O. Pelevin ◽  
A. M. Lerer ◽  
G. F. Zargano
Keyword(s):  
Computer Simulation ◽  
Antenna Arrays ◽  
Dielectric Layer ◽  
Phased Arrays ◽  
Frequency Range ◽  
Phased Antenna Arrays ◽  
Operating Frequency Range ◽  
Slotted Waveguide ◽  
Dielectric Filling ◽  
Thin Dielectric Layer

The article describes the computer simulation of phased antenna arrays consisting of slotted waveguide antennas with air and dielectric filling. It is shown that inser-tion of a thin dielectric layer shifts the operating frequency range of phased anten-na arrays by 1 GHz or more down in frequency while maintaining directional char-acteristics.

Performance Improvement of RF Inductors Using LTCC Technology

2011 ◽  
Vol 2011 (CICMT) ◽  
pp. 000054-000058 ◽  
Author(s):  
Goran Radosavljević ◽  
Andrea Marić ◽  
Walter Smetana ◽  
Ljiljana Živanov
Keyword(s):  
Experimental Data ◽  
Low Temperature ◽  
Design Optimization ◽  
Quality Factor ◽  
Performance Improvement ◽  
Air Gap ◽  
Frequency Range ◽  
Operating Frequency Range ◽  
Rf Inductors ◽  
First Time

This paper presents for the first time a parallel comparison of the performance of RF inductors realized on different substrate configurations. Presented inductors are meander type structures fabricated in Low Temperature Co-fired Ceramic (LTCC) technology. Also, chosen material is never before implemented for inductor fabrication. The performance improvement is achieved by design optimization of different substrate configurations that incorporate placement of an air-gap beneath the inductor and/or introduction of an additional shielding layer on the top. Designed structures are characterized on the basis of simulation and experimental data, achieving good correlation between obtained results. Presented results show over 30 % increase in quality factor and widening of the operating frequency range by over 55 %.

scholarly journals Wideband Printed Wide-Slot Antenna with Fork-Shaped Stub

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 347 ◽  
Author(s):  
Ke Li ◽  
Tao Dong ◽  
Zhenghuan Xia
Keyword(s):  
Wireless Communication ◽  
Communication Systems ◽  
Slot Antenna ◽  
Wireless Communication Systems ◽  
Impedance Bandwidth ◽  
Frequency Range ◽  
Slot Antennas ◽  
Resonance Technique ◽  
Operating Frequency Range ◽  
Measured Impedance

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.

scholarly journals The design and testing issues of radiation tolerant microwave amplifiers implemented in the domestic GaAs pHEMT 0.5 μm process

2019 ◽  
Vol 30 ◽  
pp. 10001
Author(s):  
Denis Sotskov ◽  
Alexander Kuznetsov ◽  
Nikolay Usachev ◽  
Vadim Elesin ◽  
Ilya Selishchev
Keyword(s):  
Radiation Effects ◽  
Noise Figure ◽  
Supply Voltage ◽  
Frequency Range ◽  
Microwave Amplifiers ◽  
Operating Frequency Range ◽  
Single Positive ◽  
Extended Frequency ◽  
Radiation Tolerant ◽  
Design And Testing

The investigation results of the possibility of manufacturing radiation tolerant microwave amplifiers implementing in domestic GaAs D-mode pHEMT 0.5 μm process are presented in this work. The amplifier with an operating frequency range from 0.1 GHz to 3.5 GHz, gain above 15 dB, noise figure below 2.2 dB, output linearity above 17 dBm is designed, produced and measured. The characteristic property of the amplifier is a single positive supply voltage and extended frequency range up to 100 MHz provided by the external capacitor circuit. Transient radiation effects in the amplifier are investigated up to the dose rate value of 4.9·109 a.u./s. The recovery time does not exceed 4 μs according to the experimental results.

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