Caracterization of the materials used as GSM and DCS antenna in free space

The use of new materials constitutes an alternative to solve the problems involved in progress of electronics nowadays. The good knowledge of the electric materials parameters is a need. For this reasons, we have developed a broad-band technique for measuring the complex relative permittivity (ε*) of dielectric materials. Our method is based on the use of a measurement bench in free space, using two antenna Vivaldi which are simulated; one used to produce electromagnetic wave and the second is to resave the electromagnetic wave. The materials are placed between the two antennas to be characterized. Many results are obtained with S parameters in transmission, using the vectorial analysis. To extract the complex permittivity we use a mathematical model.