%0 Journal Article
%@holdercode {isadg {BR SPINPE} ibi 8JMKD3MGPCW/3DT298S}
%@nexthigherunit 8JMKD3MGPCW/3ET2RFS
%X On the basis of measured scattering parameters, we present a general assessment of the main problems with the Nicholson-Ross-Weir retrieval procedure: First, the inherent instability of the method for low-loss materials at frequencies corresponding to integer multiples of the transmitted wavelength in the sample; second, the multivalued solutions for the complex wavenumber when the electrical length of the sample exceeds a wavelenghth. It is shown that the presence of small perturbation or noise on the transmission coefficient T at around |T| &#8776; 1 suffices to trigger the instability when retrieving the impedance of the sample. Unlike the ill-conditioned expression of the impedance, the product &#956;&#949; (refractive index squared) is stable to perturbation in T. For nonmagnetic materials (relative permeability &#956;<sub>r</sub> = 1), therefore, the product &#956;&#949; reduces to the complex permittivity, which is then correctly retrieved without divergent ripples as shown by the extracted permittivity spectra in the X-band (8.212.4 GHz) for a slab sample of Teflon of arbitrary thickness.
%8 Aug.
%N 11-12
%T Retrieval of permittivity and permeability of homogeneous materials from scattering parameters
%@electronicmailaddress barroso@plasma.inpe.br
%@secondarytype PRE PI
%K scattering parameters, transmission/reflection method, retrieval  of permittivity and permeability.
%@archivingpolicy denypublisher denyfinaldraft12
%@usergroup administrator
%@usergroup lattes
%@usergroup marciana
%@group LAP-CTE-INPE-MCT-BR
%@e-mailaddress barroso@plasma.inpe.br
%3 sfxlcl3.htm
%@secondarykey INPE--PRE/
%@secondarymark A1_ENGENHARIAS_IV
%F lattes: 5240243263075069 1 BarrosoPaul:2010:RePePe
%U http://www.brill.bl/jew
%@issn 0920-5071
%2 dpi.inpe.br/plutao/2010/12.02.14.29.18
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%B Journal of Electromagnetic Waves and Applications
%@versiontype publisher
%P 1563-1574
%4 dpi.inpe.br/plutao/2010/12.02.14.29.17
%@documentstage not transferred
%D 2010
%V 24
%@doi 10.1163/156939310792149759
%A Barroso, Joaquim José,
%A Paula, de,
%@dissemination WEBSCI; PORTALCAPES.
%@area FISPLASMA