Frequency-dependent factors of coupling of irregular microstrip resonators

Coupling Coefficients of Resonators in Microwave Filter Theory

“…First studies of the frequency dispersion of coupling coefficients between microstrip resonators were reported in [8,15]. A symmetrical pair of electromagnetically coupled regular microstrip resonators with tapped input and output ports was studied.…”

“…The frequency-dependent inductive coupling and capacitive coupling coefficients were defined in [8,15] as follows:…”

“…Graphs of k(ω) were plotted in [8,15] for various cases using summation rule (10) and the analytical expressions for k L (ω) and k C (ω). Also L(ω) graphs of the frequency response were computed and plotted for the same cases.…”

“…They underlie the intelligence method of filter optimization based on a priory knowledge of physical properties of resonator filters [5][6][7]. The frequency dispersion of coupling coefficients is a primary cause of the asymmetrical slopes of the filter passband [8,9]. Attenuation poles in a filter frequency response are often due to coupling coefficients becoming null [8].…”

“…The frequency dispersion of coupling coefficients is a primary cause of the asymmetrical slopes of the filter passband [8,9]. Attenuation poles in a filter frequency response are often due to coupling coefficients becoming null [8]. An energy approach to coupling coefficients gives a clue to their abnormal dependence on the distance for some resonators [3,10].…”