A NEW PROCEDURE TO DETERMINE THE PERMITTIVITY OF RADAR ABSORBING MATERIALS

• DOI: Atena

• Palavras-chave: Atena

• Keywords: radar absorber material, permeability, permittivity, vector network analyzer, time domain reflectometer, iron oxides.

• Abstract:

  Permittivity is an important

  electromagnetic (EM) property of materials used

  as radar absorbing material (RAM). Nowadays,

  there are many methods for measuring this

  property although they require very complicated

  test sets. Most of the techniques usually

  execute EM characterization of RAM with

  waveguides and vector network analyzer

  (VNA) that involves calibration procedures

  time consuming, complexity and are always

  frequency band limited according waveguide

  high pass and dominant mode operation.

  However, this combination holds certain

  complexities such errors or noise. Besides,

  waveguides, even at X band, are configured

  as large hollow metal pipes with very difficult

  assembling during measurements procedures.

  To reduce those complexities and problems,

  this paper proposes a new approach, using

  time domain reflectometry (TDR), for measuring

  the EM properties. The TDR evaluates the

  reflections in a transmission line and permits to

  analyze the properties that cause the reflection.

  Thus, in the present work, the scalar reflection

  loss techniques are used to characterize epoxy

  and epoxy/nanoferrite systems to be used as

  RAM. The epoxy/nanoferrite systems were

  produced by modifying the epoxy resin with

  nanoparticules of Fe3

  O4

  , NiFe2

  O4

  , Ni0.5Zn0.5Fe2

  O4

  at concentrations of 0%, 10% and 20%. Results

  certify that TDR techniques can be used for EM

  characterization, being a less time consuming

  measurement and broadband measurement

  method.

• Número de páginas: 15