Novel microstrip bandpass filter with controllable transmission zeros
ABSTRACT This paper presents a bandpass filter using a novel single dual-mode resonator. The resonator with notch perturbation is investigated. The transmission zeros and current distribution are discussed. The location of the transmission zeros are shifted by changing the position of input/output ports and the size of circular notch. Different selectivity in stopband can be realized by the filter. Based on the proposed dual-mode resonator, an asymmetrical frequency responses filter at center frequency of 2.4 GHz is implemented with two transmission zeros. The measured results exhibit good agreement with the simulation.