Defected ground plane microstrip resonator

This paper presents the results of a defected ground plane coupling technique that has the property of effectively enhancing the electromagnetic coupling between the input and output feed lines with a microstrip resonator. The device used to demonstrate the principle is a half-ring microstrip structure that behaves like au annular-ring resonator. The defected ground plane is shown to provide a simple hut effective coupling scheme that could be employed in wide-band filter designs in order to improve the transmission and matching characteristics.