This article presents a dielectric characterization method based on transmitted power measurements in the microwave regime for nondispersive materials. The method can retrieve the dielectric properties of materials utilizing multiobjective functions enforced at multiple frequencies without the need for phase information, which requires expensive measurement setups. Therefore, a signal generator and a power meter are all that is needed to retrieve the permittivity of materials. To validate the method numerically, two structures including free space and a coaxial line are used. For experimental verification, a coaxial line is designed and fabricated to retrieve the dielectric properties of several materials. Both simulation and measurement results show the high accuracy level of the proposed technique.