A Integrated Design Theory Of Anechoic Chamber

The construction of anechoic chamber is a complex work.The costs of manpower and material resources are great.A built anechoic chamber is hard to be changed.If the anechoic chamber can be analyzed before construction,it will guide us to build anechoic chamber and cost a little.This paper discusses in detail the dimensions of the anechoic chamber,the characteristics of the absorber and the transmitting antenna at different frequencies based on the basic theory.The design can meet these requirements of the quiet zone,the maximum reflection level,the cross polarization,the field uniformity,the path loss and so on.Different numerical methods are used to calculate the anechoic chamber with different frequency bands because the electromagnetic effect of the anechoic chamber,the characteristics of the transmitting antenna and the characteristics of the absorber are different in different frequency.The main achievements and conclusions of this paper are summarized below:(1)The dimension of the anechoic chamber is determined by the geometrical optics method according to the radiation characteristic of antenna and the size of quiet zone.(2)The relationship between the electromagnetic parameters and the surface reflection coefficient of absorber is deduced by us and simulated by HFSS and CST.(3)Electromagnetic properties of anechoic chamber in high frequency band are calculated by the geometrical optics method,especially for the derivation of the calculated approach and method in anechoic chamber with complex electromagnetic pyramidal absorber.The final results of the anechoic chamber with an equivalent plate absorber are obtained,and the results are in good agreement with the design requirements.(4)The plane wave produced by transmission line method incident on a layered discretization pyramidal absorber to simulate the local plane wave irradiation on chamber absorbing cone in low frequency band.TLM grid modeling of log-periodic antenna for transmitting source is used in anechoic chamber and the final result is great.(5)Huygens sources instead of the method that total field minus direct field to calculate reflecting field when using the TLM method to simulate the electric field distribution in the anechoic chamber.The result is a sharp reduction in the burr.(6)The design method of the chamber and the process of simulation test are gathered through the MATLAB function of GUI.The desired results can be easily and quickly obtained through the user interface settings.Users can modify the parameters of the transmit antenna according to their own requirements in different situations and obtain the result in the 3D graph,two-dimensional map and a list of expression.