The influence of sensitivity coefficient on the performance of microwave devices

Mechanical tolerances of microwave devices (MDS) introduced by the manufacturing process lead to a variation in the device performance. To obtain this variation by repeated experiments of large numbers of randomly perturbed geometries is excessively costly. An alternative is to find the changing rule of the performance with respect to each geometric variable. This paper gives a method of calculating the sensitivity coefficient of mechanical tolerances (SCMTS) of MDS. The method is clear in thought and convenient in application. It can figure out the change of the performance of the MDS due to the variation of the mechanical tolerances (VMTS). Taking the air coaxial line (ACL) as an example, the paper discusses the calculating method of SCMTS, gives the expression of the SCMTS and computes the quantity of the VMTS. In point of designing the MDS, the theoretic directive significance of the SCMTS is obvious.