Compact lowpass filter with ultra-wide stopband rejection using meandered-slot dumbbell resonator

Abstract

A novel meandered-slot dumbbell resonator for designing a compact lowpass filter (LPF) with ultra-wide stopband rejection is presented. Compared with some other reported compact and wide stopband rejection LPFs, the proposed LPF using the novel meandered-slot dumbbell resonator has great improvement on size reduction and stopband width. Delivering a 3 dB cut-off frequency at 2.2 GHz, the designed LPF achieves an ultra-wide stopband of 12.8 times the cut-off frequency with overall 20 dB attenuation. The compact dimension of this filter is as small as , where is the guide wavelength at the cut-off frequency. The proposed filter is fabricated and tested. Measured results show good agreement with simulated ones.

Acknowledgements

This work is supported by the Natural Science Foundation Project of CQ CSTC (CSTC2010BB2243), the Fundamental Research Funds for the Central Universities of CQU (CDJZR11160007), and partly by the National Natural Science Foundation of China under Contract No. 60501023.