Article Title

Rogosinski Lemması ile ilgili Süren Nokta Empedans Fonksiyonları için Carathéodory Eşitsizliği


In this paper, a boundary version of the Carathéodory’s inequality has been investigated for positive real functions. Accordingly, the driving point impedance function ��(��) where ��(��) =2+ ��1(�� − 1) + ��2(�� − 1)2+. .. is an analytic function defined in the right half of the s-plane. With the help of Rogosinski’ lemma, novel inequalities have been derived for the modulus of derivative of ��(��) by assuming that the ��(��) function is also analytic at the boundary point �� = 0 on the imaginary axis. In addition, the sharpness of presented inequalities has been proved and the spectral characteristics of resulting extremal functions have been investigated. Accordingly, it has been observed that it is possible to obtain various filter structures using proposed analysis in the study