original_query: What are the S-parameters used to calculate the power waves at each network port?
query: What are the S-parameters used to calculate the power waves at each network port?
answer: The S-parameters, represented in a matrix (S-parameter matrix), are used to calculate the reflected and incident power waves at each port of an electrical network.  The relationship is expressed as b = Sa, where 'b' is the vector of reflected power waves, 'a' is the vector of incident power waves, and 'S' is the S-parameter matrix.