Design of compact elliptic-function low-pass filters using stepped-impedance hairpin resonators

A modified low-pass filter (LPF) is developed in this paper. Stepped impedance modified-hairpin resonator is used in the filter. The filter has good performance on frequency response, stop-band and small size. ADS and HFSS simulation software is used to get good performance of the filter. For obtaining a very sharp frequency response, multiple cascaded hairpin resonators are applied to the filter. The filter is evaluated by simulation and testing with good agreement. The equivalent circuit model provides a useful method to design and understand this type of filter. Otherwise, this type of filer can be used in many microwave and millimeter-wave instrument and measurement.