Analysis of resonant behavior in planar line arrays of rings by the eigencurrent approach

Resonant behavior in a finite array that appears as (modulated) impedance or current-amplitude oscillations may limit its bandwidth substantially. Therefore, simulations should predict such behavior. Recently, a new approach has been developed, called the eigencurrent approach, which can predict resonant behavior in finite arrays. Analysis of line arrays of II-plane oriented microstrip rings by the eigencurrent approach reveals that resonant behavior is caused by excitation of one of the eigencurrents. The characteristic impedance of this eigencurrent becomes small in comparison to the characteristic impedances of the other eigencurrents that can exist on the array geometry.