scholarly journals Электромагнитные свойства полимерных композитов Li-=SUB=-0.33-=/SUB=-Fe-=SUB=-2.29-=/SUB=-Zn-=SUB=-0.21-=/SUB=-Mn-=SUB=-0.17-=/SUB=-O-=SUB=-4-=/SUB=-/П(ВДФ-ТФЭ) в области частот 100-7000 МГц

2022 ◽  
Vol 56 (1) ◽  
pp. 114
Author(s):  
И.М. Исаев ◽  
В.Г. Костишин ◽  
Р.И. Шакирзянов ◽  
А.Р. Каюмова ◽  
Д.В. Салогуб
Keyword(s):  
Reflection Coefficient ◽  
Polymer Composite ◽  
Mass Fraction ◽  
Return Loss ◽  
Spinel Ferrite ◽  
Metal Plate ◽  
Frequency Range ◽  
Combined Action ◽  
Absorption Characteristics ◽  
High Absorption

The article describes electromagnetic and microwave properties of the polymer composite with the lithium spinel ferrite inclusion of composition Li0.33Fe2.29Zn0.21Mn0.17O4 in the frequency range 100 MHz - 7000 MHz. It is shown that samples with a mass fraction of ferrite 60, 80% have pronounced radio-absorbing properties, measured using the reflection coefficient on a metal plate (return losses). For a composite with 80% ferrite, the minimum return loss was -37.5 dB at 2.71 GHz with an absorption width at -10 dB of 3 GHz. High absorption characteristics are directly related to the use of ferroelectric polymer P(VDF-TFE) as a binder, which is expressed in the combined action of the absorption mechanisms of the magnetic and ferroelectric phases.

Effect of Sendust Particle Size on Absorption Characteristics of Composite Electromagnetic Wave Absorber

2009 ◽  
Vol 421-422 ◽  
pp. 451-454
Author(s):  
Kenji Sakai ◽  
Yoichi Wada ◽  
Yuuki Sato ◽  
Shinzo Yoshikado
Keyword(s):  
Particle Size ◽  
Electromagnetic Wave ◽  
Return Loss ◽  
Single Layer ◽  
Complex Permeability ◽  
Wave Power ◽  
Flexible Design ◽  
Frequency Range ◽  
Polystyrene Resin ◽  
Absorption Characteristics

The effects of the particle size of sendust, which is an alloy of Al 5%, Si 10%, and Fe 85%, on the absorption characteristics of composite electromagnetic wave absorbers made of polystyrene resin and sendust were investigated in the frequency range from 1 to 40 GHz. The size of sendust particles was varied between approximately 5 and 20 m. A metal-backed single-layer absorber made of 20 m sendust particles absorbed more than 99% of electromagnetic wave power at frequencies above 20 GHz. Meanwhile, a composite made of 5 m particles exhibited a return loss of less than −20 dB in the frequency range of not only several GHz but also above 30 GHz. In addition, the relative complex permeability r* was shown to be controlled by adjusting the particle size of sendust, and an electromagnetic wave absorber with a flexible design was proposed.

scholarly journals Магнитные и радиопоглощающие свойства поликристаллического феррита-шпинели Li-=SUB=-0.33-=/SUB=-Fe-=SUB=-2.29-=/SUB=-Zn-=SUB=-0.21-=/SUB=-Mn-=SUB=-0.17-=/SUB=-0-=SUB=-4-=/SUB=-

2021 ◽  
Vol 91 (9) ◽  
pp. 1376
Author(s):  
И.М. Исаев ◽  
В.Г. Костишин ◽  
В.В. Коровушкин ◽  
Д.В. Салогуб ◽  
Р.И. Шакирзянов ◽  
...  
Keyword(s):  
Magnetic Permeability ◽  
Spinel Ferrite ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Metal Plate ◽  
Ceramic Technology ◽  
Practical Application ◽  
Frequency Range ◽  
Complex Magnetic Permeability ◽  
Magnetic Hysteresis Loops

Polycrystalline spinel ferrites of the composition Li0.33Fe2.29Zn0.21Mn0.17O4 were synthesized by using the ceramic technology method at sintering temperatures of 950 ° C, 1000 ° C, 1050 ° C, and 1100 ° C. Magnetic hysteresis loops and magnetic permeability of the experimental samples were studied in the range of magnetic fields of -400–400 A/m. In the frequency range of 0.01–7.0 GHz, the behavior of the complex dielectric and complex magnetic permeability, as well as the reflection coefficient on a metal plate, are investigated. It was found that the optimal sintering temperature range for synthesized ferrites is from 1050 ° C to 1100 ° C. It is shown that the spinel ferrite Li0.33Fe2.29Zn0.21Mn0.17O4 intensely absorbs electromagnetic radiation in the frequency range from 0.05 to 7.0 GHz. Possibilities of practical application of the obtained results are discussed.

scholarly journals Bi-Ellipse Microstripline Antenna Array Varians

2021 ◽  
Author(s):  
Putu Artawan
Keyword(s):  
Reflection Coefficient ◽  
Antenna Array ◽  
Standing Wave ◽  
Microstrip Antenna ◽  
Communication Systems ◽  
Return Loss ◽  
Voltage Standing Wave Ratio ◽  
Frequency Range ◽  
X Band ◽  
Working Frequency

The objectives of this research include obtaining and verifying the impedance formula of the designed bi-ellipse microstrip antenna and correlating the results obtained through simulation and experimentation. The research also aims to obtain the structure and dimensions that provide optimal characteristics of the designed bi-ellipse microstrip antenna and produce a prototype at S, C and X-Band frequencies. This research produced the structure and dimensions of a bi-ellipse microstrip antenna that provide optimal characteristics of antenna. The characteristics results of the antenna parameters in this research include a 8x2 array, with a bandwidth value of around 100.0 MHz obtained at a working frequency of 7.09GHz (7.04 GHz - 7.14 GHz), with a reflection coefficient value of 0.02, Voltage Standing Wave Ratio (VSWR) of 1.06, return loss of −30.00 dB and a gain of 7.30 dB. For the 8x4 array, a bandwidth value of approximately 210.0 MHz is obtained at a working frequency range of 2.85GHz, which ranges from 2.74GHz - 2.95GHz, with a reflection coefficient value of 0.04, Voltage Standing Wave Ratio (VSWR) of 1.09, return loss of −27.06 dB and a gain of 8.19 dB. The results presented above fulfill the indicators of good antenna characteristics parameters applicable to radar communication systems.

scholarly journals Band notched self complementaryultra wideband antenna for wireless applications

2018 ◽  
Vol 7 (2.8) ◽  
pp. 529 ◽  
Author(s):  
Ch Ramakrishna ◽  
G A.E.Satish Kumar ◽  
P Chandra Sekhar Reddy
Keyword(s):  
High Frequency ◽  
Return Loss ◽  
Wide Band ◽  
Ultra Wideband ◽  
Impedance Bandwidth ◽  
Relative Dielectric Permittivity ◽  
Frequency Range ◽  
Ground Structure ◽  
Wireless Applications ◽  
Patch Edge

This paper presents a band notched WLAN self complementaryultra wide band antenna for wireless applications. The proposed antenna encounters a return loss (RL) less than -10dB for entire ultra wideband frequency range except band notched frequency. This paper proposes a hexagon shape patch, edge feeding, self complementary technique and defective ground structure. The antenna has an overall dimensionof 28.3mm × 40mm × 2mm, builton  substrate FR4 with a relative dielectric permittivity 4.4. And framework is simulated finite element method with help of high frequency structured simulator HFSSv17.2.the proposed antenna achieves a impedance bandwidth of 8.6GHz,  band rejected WLAN frequency range 5.6-6.5 GHz with  vswr is less than 2.

scholarly journals Flexible Broadband Metamaterial Perfect Absorber Based on Graphene-Conductive Inks

Photonics ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 440
Author(s):  
Le Van Long ◽  
Nguyen Sy Khiem ◽  
Bui Son Tung ◽  
Nguyen Thanh Tung ◽  
Trinh Thi Giang ◽  
...  
Keyword(s):  
Impedance Matching ◽  
Optical Filters ◽  
Wide Frequency Range ◽  
Absorption Feature ◽  
Perfect Absorber ◽  
Frequency Range ◽  
Absorption Mechanism ◽  
Polarization Insensitive ◽  
Metamaterial Perfect Absorber ◽  
High Absorption

In this work, we proposed a flexible broadband metamaterial perfect absorber (FBMPA) by exploiting a pasted conductive-graphene ink on a polyimide substrate. For the flat FBMPA, an absorption over 90% was found to cover a wide frequency range (from 7.88 to 18.01 GHz). The high-absorption feature was polarization-insensitive and regarded as stable with respect to the oblique incidence up to 30 degrees of electromagnetic wave. The high absorption was maintained well even when the absorber was wrapped. That is, the FBMPA was attached to cylindrical surfaces (with the varying radius from 4 to 50 cm). For both flat and curved states, the absorption mechanism was explained by the perfect impedance matching and the dielectric loss of the proposed absorber. Our work provides the groundwork for the commercialization of future meta-devices such as sensors, optical filters/switchers, photodetectors, and energy converters.

scholarly journals A Novel Frequency Reconfigurable Microstrip Patch Antenna using Pin Diode

2020 ◽  
Vol 9 (5) ◽  
pp. 2013-2017
Keyword(s):  
Patch Antenna ◽  
Return Loss ◽  
Microstrip Patch Antenna ◽  
Pin Diode ◽  
Optimum Level ◽  
Frequency Range ◽  
Microstrip Patch ◽  
Single Antenna ◽  
Specific Frequency ◽  
Switching State

In recent study, in the growth of wireless technology single antenna that works with a specific frequency is becoming outdated. The antenna which is capable to work dynamically is encouraged. To make an antenna to work dynamically, modification in any of the antenna characteristics can be applied. In this proposed work, the antenna which can reconfigure its frequency is designed and analyzed. Microstrip patch antenna is most popular printed type antenna which is suitable for diverse applications. The antenna design consists of three PIN diodes which are placed in different positions on the patch. Depending upon the switching state of PIN diode the antenna can operate in different frequency ranges. The frequency range obtained ranges from 1.38 GHz to 3.24 GHz. Return loss value, VSWR obtained is of optimum level. The various gain of antenna is obtained in simulation. The analysis of the antenna is done in ANSYS HFSS software.

A Patch Antenna Design for Giga Frequency Unmanned Aerial Vehicles Application

2021 ◽  
Vol 13 (1) ◽  
pp. 01-07
Author(s):  
Dr.M.D. Javeed Ahammed ◽  
Dr.G. Srinivasa Rao
Keyword(s):  
Patch Antenna ◽  
Return Loss ◽  
Surface Current ◽  
Vital Role ◽  
Frequency Range ◽  
Gain Bandwidth ◽  
Proposed Model ◽  
Major Parameter ◽  
Aerospace Technology ◽  
Conventional Models

In this paper a present time developing application is used that is a UAV Antenna in aerospace technology. These antennas play a vital role in this WIMAX technology. A patch antenna is designed such that all the dimensions should be shrinked yet efficient in radiation in comb shape and this proposed antenna is used at 4.2GHz frequency range. A CST tool is used for designing and simulating our antenna all the dimensions taken for proposed antenna are comparatively less when compared to conventional models. Low return loss, gain, bandwidth and VSWR are optimized by using this design the efficiency is also enhanced by 95% which makes our antenna suitable to the UAV WIMAX applications. Surface current is also one of the major parameter which is reduced by our proposed model.

scholarly journals Design and Development of a Wideband Planar Yagi Antenna Using Tightly Coupled Directive Element

Micromachines ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 975
Author(s):  
Muhammad A. Ashraf ◽  
Khalid Jamil ◽  
Ahmed Telba ◽  
Mohammed A. Alzabidi ◽  
Abdel Razik Sebak
Keyword(s):  
Reflection Coefficient ◽  
Wireless Communication ◽  
Radiation Pattern ◽  
Excellent Agreement ◽  
Frequency Range ◽  
Fractional Bandwidth ◽  
Yagi Antenna ◽  
Tightly Coupled ◽  
Simulation Results ◽  
Novel Concept

In this paper, a novel concept on the design of a broadband printed Yagi antenna for S-band wireless communication applications is presented. The proposed antenna exhibits a wide bandwidth (more than 48% fractional bandwidth) operating in the frequency range 2.6 GHz–4.3 GHz. This is achieved by employing an elliptically shaped coupled-directive element, which is wider compared with other elements. Compared with the conventional printed Yagi design, the tightly coupled directive element is placed very close (0.019λ to 0.0299λ) to the microstrip-fed dipole arms. The gain performance is enhanced by placing four additional elliptically shaped directive elements towards the electromagnetic field’s direction of propagation. The overall size of the proposed antenna is 60 mm × 140 mm × 1.6 mm. The proposed antenna is fabricated and its characteristics, such as reflection coefficient, radiation pattern, and gain, are compared with simulation results. Excellent agreement between measured and simulation results is observed.

scholarly journals Study and analysis of discontinuity by using taper baluns

2015 ◽  
Vol 4 (2) ◽  
pp. 283
Author(s):  
Hussein Aldahhan ◽  
Bashar Qas Elias
Keyword(s):  
Reflection Coefficient ◽  
Transmission Line ◽  
Insertion Loss ◽  
Power Flow ◽  
Microstrip Line ◽  
Return Loss ◽  
Wide Band ◽  
Coplanar Stripline ◽  
Insertion Losses

A coplanar stripline (CPS) to microstrip line transition (MSL) are designed with high characteristics, such as wide band, low return loss and high insertion loss. Two types of tapers are proposed, exponential and triangular to decreases of discontinuity in the power flow in transmission line. The suggested design achieved reflection coefficient under -10 dB over wide band from 1 GHz to 3 GHz and insertion losses of less than 1 dB.

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