A Novel Miniaturized Narrow Band Bandpass Filter Utilizing Microstrip Open-loop Ring Resonators for Narrow-band Applications

In this paper, a novel compact topology of microstrip open-loop ring resonator is introduced to design narrowband bandpass filters with better performance in making trade-off between insertion loss and bandwidth. The proposed structure comprises of two microstrip open-loop ring resonators only with magnetic coupling instead of electrical, magnetic and mixed ones in the conventional ones. The performance of this novel bandpass filter is simulated using an EM simulation tool and simultaneously compared with the conventional one which confirms the priority of this filter to them. The proposed NB BPF provides a narrowband bandpass filter with a bandwidth of 0.91% and better insertion and return losses in comparison with the conventional ones. Additionally, a size reduction about 36% is also reported by this novel layout.