To reduce the size and improve the performance, a 4th-order miniaturized dual-mode microstrip bandpass filter (BPF) is developed. A meander shorted stub loaded resonator is used, and much compact size is obtained. Theoretical model is set up, and the odd and even modes of the BPF are analyzed based on a symmetrical structure. Full wave simulation validates the design method. To verify the design, a fabricated BPF sample has been tested. Experiment result demonstrates that the designed BPF has wider stopband and better selectivity. Its fractional bandwidth and a center frequency are available.
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