Parameters in Modal Domain

By applying modal transformation, differential equations in a multiconductor are given as 

Equation 1.152 in a modal domain takes the same form as that in a phase domain. In a modal domain, the impedance and admittance are defined by Equation 1.153. 

In order for a product of two matrices to be a diagonal matrix, the two matrices have to be diagonal matrices. Since Q is a diagonal matrix, z and y are diagonal matrices (Wedepohl [14]). 

For a semi-infinite line, the following equation is satisfied  

The characteristic impedance and admittance in a modal domain are defined 

---