Comments on "Macromodeling of Multiport Systems Using a Fast Implementation of the Vector Fitting Method"
Luc F. Knockaert · IEEE Microwave and Wireless Components Letters · 2009
In the above letter [1], a sparse set of coupled equations (in theleast squares sense) is decoupled by applying a QR decomposition[1,eq.(10)]toeachoftheblockrowsofitsdefiningmatrix[1,eq.(8)].The QR approach makes it possible to eliminate (in a least squaressense) all the numerator coefficients , resulting in equations con-taining only the denominator coefficients . The QR algorithm wasborrowed from [2] where it was proposed without apparent proof. Theaim of this comments is twofold.First, to point out that the QR approach was proposed earlier ina total least squares system identification context by Verboven