In this paper,we introduced the coefficient of thermal radiation(Gray coefficient),It is one of the important physical properties of the textile materials.

This article introduce the foundmental and scheme about a measure instrument about gray coefficient of textile based on SOPC technology;It demonstrate to us both the architecture about the hardware and the software arithmetic;It alse introduce how to usethe IP CORE about NIOS II and the co-disign methord with hardware and software based on SOPC technology at the same time.

A set of formulae for calculating the equivalent permittivity ε_(eff) and equivalent permeability μ_(eff) of multilayer absorbing material based on reflection coefficient and transmission coefficient was presented.

The existing reflection and transmission coefficients of a frequency selective surface(FSS) do not apply to calculation of reflection and transmission under normal incidence of waves,and need to be modified.

This paper discusses the basic theory and analytical steps of using indirect ray method to calculate power transmission coefficient, boresight error and boresight error slope of large dimension radome.

The relations of transmitted and scattered radiation transfer coefficient and sensitivity with energy of radiation source,the position of scattered detector, the diameter of transmitted collimator,material of window and gas volume fraction are simulated using the software of Geant4.

After discussing the inflience caused by different negative feedback configuration s port conditions on circuit transfer coefficientG s, an united calculation formulae of source gain A· fs and clsed gain A· f, of input resistance r if and output resistance r of are found.