Compact Microstrip Lowpass Filter Using Asymmetric Stepped-Impedance Hairpin Resonator and Slotted Ground Plane

In this paper, a newly compact low pass filter is introduced. This filter is constructed by using novel asymmetric stepped-impedance hairpin resonator and slotted ground plan for size reduction and spurious suppression. Furthermore, the equivalent circuit model of the proposed resonator is set up and analyzed. Additionally, slotted ground plane are adopted to obtain a good stop band characteristics. Finally, this compact filter was designed, fabricated, and measured. The experimental results of the filter have a good agreement with the simulated results.