A Method for Extracting Coupling Matrix of Lossless Filtering Antenna From Reflection Coefficient

In this paper, a coupling matrix extraction method for designing a filtering antenna using EM simulator software is presented. Firstly, the dielectric loss and conductor loss of the filtering antenna are removed in the EM simulator to calculate the lossless simulated reflection coefficient. Then, the vector fitting method is used to fit the simulated data to obtain the characteristic polynomials
$E(s)$
and
$F(s)$
. Since the data is lossless, the other two polynomials
$P(s)$
and
$F22(s)$
can also be determined. Finally, the coupling matrix is calculated by these extracted characteristic polynomials and the antenna structure can be tuned by comparing the extracted coupling matrix with the target one.