A new technique for determining the complex permittivity of a material is proposed. This proposed technique considers only the magnitude of mutual coupling obtained from co and cross polarized dipoles. According to this technique, the complex permittivity can be determined by measuring magnitude of mutual coupling from the two cases, first is parallel-in-echelon dipoles and another case is perpendicular dipoles. To prove this technique, the complex permittivity of distilled water at the frequency of 2.45 GHz has been compared with the simulation results obtained from this technique. The antenna length of halfwave in dielectric which dielectric constant close to the measured material provides more accurate results than that of different from the measured one.
