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1
Content available Analysis of Pyramidal Microwave Absorbers for Enhanced Performance in 1 - 10 GHz Frequency Range
Thanoon Aya Raad, Sayidmarie Khalil H.
Journal of Telecommunications and Information Technology
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2025
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nr 2
29--37
EN
One of the main applications of microwave absorbers is in anechoic chambers, where the walls are lined with pyramidal foam impregnated with a lossy material. This paper investigates the impact that various design parameters of pyramidal microwave absorbers exert on their performance, with the aim of finding the best design values that ensure better operational properties. Typical pyramid absorbers were investigated by conducting simulations with the use of the CST Microwave Suite simulator, across the frequency range of 1 - 10 GHz, at various angles of the incident wave. The investigations also considered absorbers backed by conducting plates that are used in shielded anechoic chambers. The study shows that higher permittivity leads to higher reflection, while increased loss tangent improves absorption, and the same applies to magnetic materials. Larger pyramid heights lead to lower reflection, but only in the case of thicker absorbers. A pyramidal absorber with the height of 16 cm, designed using lossy material with permittivity and permeability of 1.5 and loss tangent of 0.5 achieved a reflection coefficient that was lower than –60 dB for frequencies between 3 and 10 GHz. The results are useful in designing absorbers relying on materials that offer only dielectric or magnetic properties, or that combine both of them to achieve enhanced performance.
2
Content available Absorber grafenowy do zabezpieczania bezzałogowych statków powietrznych
Kubacki Roman, Przesmycki Rafał, Laskowski Dariusz
Przegląd Elektrotechniczny
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2024
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R. 100, nr 1
255--258
PL
W pracy przedstawiono badania przenikalności elektrycznej i magnetycznej zredukowanego tlenku grafenu w zakresie częstotliwości od 100 MHz do 10 GHz. Badania przeprowadzono dla litego materiału uzyskanego z postaci proszkowej poprzez sprasowanie pod naciskiem 2 kN. Na tej podstawie określono współczynnik pochłaniania warstwy materiałów o grubościach 2.5 oraz 5 mm. Badany materiał może być zastosowany jako absorber mikrofalowy, charakteryzujący się wysoką skutecznością ekranowania, do zabezpieczania elektroniki bezzałogowych statków powietrznych, narażonych na promieniowanie emitowane między innymi przez anteny nadawcze stacji bazowych telefonii komórkowej.
EN
In the work the investigation of the permittivity and permeability of the reduced graphene oxide within the frequency range from 100 MHz to 10 GHz has been presented. Investigation were carried out for solid material obtained from the powder form across pressing under pressure of 2 kN. On this base one determined the absorption factor of material layers of thicknesses 2.5 and 5 mm. Investigated material can be applied as microwave absorber, characterized with high shielding effectiveness, to protect of the electronics of unmanned aerial vehicles, exposed to microwave radiation emitted by antennas of the cellular base stations
3
Content available Polarization Independent Ultra-wideband Meta-material Absorber Using Conductive Ink Resonator
Kumari Bharti, Kumar Abhinav, Kumar Prashant, Singh Mintu
Journal of Telecommunications and Information Technology
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2024
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nr 1
39--45
EN
A wideband meta-material absorber with square and circular split rings that is based on a frequency selective surface of conductive ink is proposed. With over 90% absorptivity, the structure demonstrates broad absorption for the C, X, KU and K bands, as well as polarization independent characteristics for both TE and TM, at angles of up to 45°. Research has been performed to better understand the absorption phenomenon by looking into real and imaginary permittivity, permeability, normalized impedance, and surface current density. The meta-material absorber (MA) discussed in this study finds use in defense-related applications, such as radar surveillance, stealth technology, terrestrial and satellite communications.
4
A new approach to microwave absorbers
Olszewska K., Gwarek W.
Elektronika : konstrukcje, technologie, zastosowania
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2012
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Vol. 53, nr 7
22-24
EN
This paper presents a new design of an absorbing screen based on a classical Salisbury concept. In the new design a resistive sheet from the classical Salisbury screen is replaced by a patterned layer. This allows eliminating major disadvantages of classical solutions, such as their narrow frequency bandwidth and high overall screen thickness. Electromagnetic simulations with QuickWave - 3D package are performed and confirm the theoretical predictions of the paper.
PL
Artykuł prezentuje nowe podejście do struktur absorbujących, oparte o klasyczne rozwiązanie typu Salisbury. W zaproponowanej strukturze, jednorodna warstwa rezystywna zastąpiona została przez warstwę wzorów. Takie rozwiązanie pozwala na wyeliminowanie głównych wad klasycznych struktur, którymi są wąskie pasmo pracy oraz duża grubość panelu. Symulacje elektromagnetyczne potwierdzające słuszność przyjętej koncepcji, przeprowadzono w programie QuickWave - 3D.
5
Content available remote Evaluation of electromagnetic absorbing capacity of materials in foundry industry
Nowak D., Stachowicz M., Pigiel M.
Archives of Foundry Engineering
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2010
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Vol. 10, iss. 1 spec.
237--242
EN
In the paper, a research on determining the standing wave ratio as a measure of electromagnetic absorbing capacity of moulding materials is presented. Preliminary tests performed using a microwave strip line showed that high-silica, chromite and magnesite moulding sands are characterised by low absorbing capacity of microwaves. It was demonstrated that microwave absorbing capacity is significantly affected by chemical compounds included in the examined substrates. It was found that use of a microwave strip line permits precise determining characteristic microwave absorbing capacities of various moulding materials and thus their suitability for microwave drying/hardening of moulds and cores or for other foundry processes. Such a microwave drier can be applied for identifying mass components and for determining e.g. base granularity by means of precisely determined reflection ratios |Γ| and positions of minimum signal values.
6
Content available remote New generation of microwave absorbers
Tabaczyńska M., Wiśniewski A., Szugajew L.
Problemy Techniki Uzbrojenia
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2002
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R. 31, z. 82
83--91
EN
In the article, some aspects of using absorbers for increasing the value of Polish armament equipment are presented. Preliminary results of research of microwave absorber of new generation, paint coating type, put on armoured vehicle of battle-field reconnaissance, are presented. The parameters of this absorber suppresion, efficiently diminishing detection range by radar of vehicle with this absorber, are showed.
PL
W artykule przedstawiono niektóre aspekty zastosowania absorberów do podniesienia walorów bojowych polskiego sprzętu uzbrojenia. Zaprezentowano wstępne wyniki badań absorbera mikrofalowego drugiej generacji typu powłoka malarska, naniesionego na opancerzony pojazd rozpoznania pola walki. Pokazano parametry tłumienia tego absorbera, skutecznie zmniejszającego zasięg wykrycia pojazdu z tym absorberem przez radar.
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