A novel compact bandpass filter using hairpin microstrip folded lines configuration with transmission zeros

A novel compact microstrip bandpass filter which is realized by combining new slow-wave effect with hairpin microstrip folded lines configuration, is proposed. The filter is not only compact in size due to the slow-wave effect, but also has multi-transmission zeros on both sides of the passband, and low insertion loss in bandpass. The filter has, for the first time, been optimally designed and fabricated. The results of the theory and experiment are demonstrated. The agreement between the predicted and measured results is excellent.