A DE-EMBEDDING ALGORITHM FOR ELECTROMAGNETICS

A "double delay" de-embedding algorithm appropriate for electromagnetic analyses is described. This algorithm uses only two standards, a through and a double length through. By evaluating these standards, a special class of port discontinuities may be characterized and removed from the data calculated for a complete structure. Unlike related physical de-embedding algorithms, both the characteristic impedance and the velocity of propagation of the through lines are determined. The technique described here is difficult to implement in a physical de-embedding. The de-embedding theory also provides a new definition of characteristic impedance, "equivalent TEM impedance," for inhomogeneous media, such as microstrip. This new impedance exhibits a nonmonotonic dispersion which has been measured experimentally but is not seen using previous impedance definitions.