In dielectric spectroscopy, an analysis is made of the function of the

complex permeability [[epsilon].sup.*] of insulation by the frequency and voltage range [5-7]:

The reflection loss (RL) of composite nanofibers was calculated by Matlab based on the relatively

complex permeability and permittivity at a given frequency and matching thickness according to the following equations:

With respect to dynamic magnetic properties, we calculated the frequency- dependent

complex permeability for the Zn-Co-Ni ferrite film using Eq.

Complex permeability ([mu]' and [mu]") was calculated from [B.sub.m] cos [delta]/([[mu].sub.0][H.sub.m]) and [B.sub.m] sin [delta]/([[mu].sub.0][H.sub.m]), respectively, where [delta] is phase difference and can be obtained directly from the computer measurement and control system.

The value of imaginary part ('') of

complex permeability decreases after Sm3+ substitution while no change observed in real part (') of

complex permeability with Sm3+ substitution for all samples which has been discussed using electromagnetic theory.

Lossy magnetic wires are characterized by a

complex permeability [[mu].sub.m] and complex permittivity [[epsilon].sub.m].

Conventional spinel type ferrites do not function well in the GHz range due to a drop in the

complex permeability ([[mu].sub.r]) as given by Snoek's limit [3].

Application of materials in the microwave, aerospace, and communications demands an accurate knowledge of material properties such as complex permittivity and

complex permeability. The active research fields like materials science and electrical and electronic engineering [1] need necessarily information about permittivity and permeability for developing novel microwave materials.

The properties of a material may be specified by two complex constants called complex permittivity ([epsilon]) or dielectric constant and

complex permeability ([mu]).

Szendrenyi, et al., "An Alternative Broadband Method for Automatic Measurement of the

Complex Permeability and Permittivity of Materials at Microwave Frequencies," IEEE MTT-S Symp.

Hatakeyama, "Frequency dispersion and temperature variation of

complex permeability of Ni-Zn ferrite composite materials," J.

Varadan, "A free-space measurement of complex permittivity and

complex permeability of magnetic materials at microwave frequencies," IEEE Trans.