Microstrip cross-coupled bandpass filter with asymmetric frequency characteristic

摘要

A microstrip cross coupling bandpass filter includes an input port, an input resonator, an output port, and an output resonator. The input port and the input resonator are electric-coupled, and the output port and the output resonator are electric-coupled. A cross coupling gap corresponding to the distance between the input and output resonators forms magnetic coupling. The bandpass filter further includes a cross coupling line electric-coupled with the input and output ports. The cross coupling gap generates an attenuation pole on the high side of a passband. The attenuation frequency of the attenuation pole can be varied with the distance of the cross coupling gap. The cross coupling line generates an attenuation pole on the high and low sides of the passband.