Electromagnetic and absorption properties of some microwave absorbers

Ahmad Nazlim Yusoff, M. H. Abdullah, Sahrim Ahmad, S. F. Jusoh, A. A. Mansor, S. A A Hamid

Research output: Contribution to journalArticle

410 Citations (Scopus)

Abstract

Electromagnetic properties of a thermoplastic natural rubber (TPNR), a lithium-nickel-zinc (Li-Ni-Zn) ferrite and a TPNR-ferrite composite subjected to transverse electromagnetic (TEM) wave propagation were investigated. The incorporation of the ferrite into the matrix of the TPNR was found to reduce the dielectric loss but the magnetic loss increased. The absorption characteristics of all the samples subjected to a normal incidence of TEM wave were investigated based on a model of a single-layered plane wave absorber backed by a perfect conductor. It is evident from a computer simulation that the ferrite is a narrowband absorber, whereas the polymeric samples show broadband absorption characteristics. Minimal reflection of the microwave power or matching condition occurs when the thickness of the absorbers approximates an odd number multiple of a quarter of the propagating wavelength. This is discussed as due to cancellation of the incident and reflected waves at the surface of the absorbers. The Li-Ni-Zn ferrite exhibits another matching condition at low frequency when the magnitude of the complex relative dielectric permittivity (ε r *) equals that of the complex relative magnetic permeability (μ r *). The specular absorber method provides a simple theoretical graphic aid for determining the absorption characteristics and the location of the matching conditions in the frequency domain. The result for the ferrite sample was tested and confirmed directly from terminated one-port measurements.

Original languageEnglish
Pages (from-to)876-882
Number of pages7
JournalJournal of Applied Physics
Volume92
Issue number2
DOIs
Publication statusPublished - 15 Jul 2002

Fingerprint

electromagnetic properties
electromagnetic absorption
ferrites
absorbers
microwaves
rubber
electromagnetic radiation
lithium
zinc
nickel
reflected waves
dielectric loss
cancellation
narrowband
wave propagation
plane waves
conductors
incidence
computerized simulation
permittivity

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Electromagnetic and absorption properties of some microwave absorbers. / Yusoff, Ahmad Nazlim; Abdullah, M. H.; Ahmad, Sahrim; Jusoh, S. F.; Mansor, A. A.; Hamid, S. A A.

In: Journal of Applied Physics, Vol. 92, No. 2, 15.07.2002, p. 876-882.

Research output: Contribution to journalArticle

Yusoff, Ahmad Nazlim ; Abdullah, M. H. ; Ahmad, Sahrim ; Jusoh, S. F. ; Mansor, A. A. ; Hamid, S. A A. / Electromagnetic and absorption properties of some microwave absorbers. In: Journal of Applied Physics. 2002 ; Vol. 92, No. 2. pp. 876-882.
@article{aac275d5787e412aa9e6c81e4eafe971,
title = "Electromagnetic and absorption properties of some microwave absorbers",
abstract = "Electromagnetic properties of a thermoplastic natural rubber (TPNR), a lithium-nickel-zinc (Li-Ni-Zn) ferrite and a TPNR-ferrite composite subjected to transverse electromagnetic (TEM) wave propagation were investigated. The incorporation of the ferrite into the matrix of the TPNR was found to reduce the dielectric loss but the magnetic loss increased. The absorption characteristics of all the samples subjected to a normal incidence of TEM wave were investigated based on a model of a single-layered plane wave absorber backed by a perfect conductor. It is evident from a computer simulation that the ferrite is a narrowband absorber, whereas the polymeric samples show broadband absorption characteristics. Minimal reflection of the microwave power or matching condition occurs when the thickness of the absorbers approximates an odd number multiple of a quarter of the propagating wavelength. This is discussed as due to cancellation of the incident and reflected waves at the surface of the absorbers. The Li-Ni-Zn ferrite exhibits another matching condition at low frequency when the magnitude of the complex relative dielectric permittivity (ε r *) equals that of the complex relative magnetic permeability (μ r *). The specular absorber method provides a simple theoretical graphic aid for determining the absorption characteristics and the location of the matching conditions in the frequency domain. The result for the ferrite sample was tested and confirmed directly from terminated one-port measurements.",
author = "Yusoff, {Ahmad Nazlim} and Abdullah, {M. H.} and Sahrim Ahmad and Jusoh, {S. F.} and Mansor, {A. A.} and Hamid, {S. A A}",
year = "2002",
month = "7",
day = "15",
doi = "10.1063/1.1489092",
language = "English",
volume = "92",
pages = "876--882",
journal = "Journal of Applied Physics",
issn = "0021-8979",
publisher = "American Institute of Physics Publising LLC",
number = "2",

}

TY - JOUR

T1 - Electromagnetic and absorption properties of some microwave absorbers

AU - Yusoff, Ahmad Nazlim

AU - Abdullah, M. H.

AU - Ahmad, Sahrim

AU - Jusoh, S. F.

AU - Mansor, A. A.

AU - Hamid, S. A A

PY - 2002/7/15

Y1 - 2002/7/15

N2 - Electromagnetic properties of a thermoplastic natural rubber (TPNR), a lithium-nickel-zinc (Li-Ni-Zn) ferrite and a TPNR-ferrite composite subjected to transverse electromagnetic (TEM) wave propagation were investigated. The incorporation of the ferrite into the matrix of the TPNR was found to reduce the dielectric loss but the magnetic loss increased. The absorption characteristics of all the samples subjected to a normal incidence of TEM wave were investigated based on a model of a single-layered plane wave absorber backed by a perfect conductor. It is evident from a computer simulation that the ferrite is a narrowband absorber, whereas the polymeric samples show broadband absorption characteristics. Minimal reflection of the microwave power or matching condition occurs when the thickness of the absorbers approximates an odd number multiple of a quarter of the propagating wavelength. This is discussed as due to cancellation of the incident and reflected waves at the surface of the absorbers. The Li-Ni-Zn ferrite exhibits another matching condition at low frequency when the magnitude of the complex relative dielectric permittivity (ε r *) equals that of the complex relative magnetic permeability (μ r *). The specular absorber method provides a simple theoretical graphic aid for determining the absorption characteristics and the location of the matching conditions in the frequency domain. The result for the ferrite sample was tested and confirmed directly from terminated one-port measurements.

AB - Electromagnetic properties of a thermoplastic natural rubber (TPNR), a lithium-nickel-zinc (Li-Ni-Zn) ferrite and a TPNR-ferrite composite subjected to transverse electromagnetic (TEM) wave propagation were investigated. The incorporation of the ferrite into the matrix of the TPNR was found to reduce the dielectric loss but the magnetic loss increased. The absorption characteristics of all the samples subjected to a normal incidence of TEM wave were investigated based on a model of a single-layered plane wave absorber backed by a perfect conductor. It is evident from a computer simulation that the ferrite is a narrowband absorber, whereas the polymeric samples show broadband absorption characteristics. Minimal reflection of the microwave power or matching condition occurs when the thickness of the absorbers approximates an odd number multiple of a quarter of the propagating wavelength. This is discussed as due to cancellation of the incident and reflected waves at the surface of the absorbers. The Li-Ni-Zn ferrite exhibits another matching condition at low frequency when the magnitude of the complex relative dielectric permittivity (ε r *) equals that of the complex relative magnetic permeability (μ r *). The specular absorber method provides a simple theoretical graphic aid for determining the absorption characteristics and the location of the matching conditions in the frequency domain. The result for the ferrite sample was tested and confirmed directly from terminated one-port measurements.

UR - http://www.scopus.com/inward/record.url?scp=0037101070&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0037101070&partnerID=8YFLogxK

U2 - 10.1063/1.1489092

DO - 10.1063/1.1489092

M3 - Article

AN - SCOPUS:0037101070

VL - 92

SP - 876

EP - 882

JO - Journal of Applied Physics

JF - Journal of Applied Physics

SN - 0021-8979

IS - 2

ER -