Hello Everyone, I am using Agilent E5071C network analyzer for the measurement of permittivity, permeability and Microwave absorption. In recent few days the Network analyzer start giving the negative value of imaginary part of permittivity and imaginary part of permeability. I know, it is not possible to be these values in negative. But i dont know the reason why the network analyzer giving contineously negative values for various samples. Kindly help me to understand. Here is some example results of CoNi nanoparticles 20% with wax.