%0 Journal Article 
%A Albero Ortíz, Antonio
%A Monzó Cabrera, Juan
%A Díaz Morcillo, Alejandro Benedicto
%A Requena Pérez, María Eugenia
%T Combined use of genetic algorithms and gradient descent optimization methods for accurate inverse permittivity measurement
%D 2006
%@ 0018-9480
%U http://hdl.handle.net/10317/1427
%X A novel inverse transmission-line method for the
complex permittivity determination of arbitrary shaped materials
is presented. Complex permittivity is inferred by using an inverse
calculation procedure, which is based on a combined optimization
strategy of both genetic algorithms and the gradient descent
method. The optimization procedure matches the measured and
simulated complex scattering parameters’ frequency behavior
of materials within a WR340 waveguide. High accuracy and
practical suitability are validated through experimental tests.
The dielectric properties of PTFE and epoxy resin mixed with
iron–oxide-doped fiberglass have been measured for different
shapes and positions. Dielectric multilayer structures have been
used to demonstrate that this technique is able to measure the
individual permittivity of each element of the structure. Both twoand
three-dimensional approaches have been carried out and their
advantages and drawbacks discussed.
%K Teoría de la Señal y las Comunicaciones
%K Medición de permitividad compleja
%K Método GD
%K Energía de microondas
%K Complex permittivity measurement
%K Gradient descent (GD) method
%K Microwave energy
%K Algoritmos genéticos (AG)
%K Genetic algorithm (GA)
%~ GOEDOC, SUB GOETTINGEN