A Novel $N$-Port Characteristic Mode Formulation Based on Admittance Matrix

In this paper, a novel <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$N$</tex>-port characteristic mode (CM) formulation based on admittance matrix is proposed. Based on the voltage-far-field-basis and the port voltage, the radiated-power-related matrix is acquired. Consequently, the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$N$</tex>-port CM formulation can be developed. Compared to the traditional <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$N$</tex>-port CM formulation, the eigenvalues of the proposed CM formulation have significant physical interpretation. Moreover, this paper provides a novel approach for selecting appropriate loads based on the proposed <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$N$</tex>-port CM theory, thereby enabling the system to operate over the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\boldsymbol{n}$</tex>th CM.