A COMPACT DUAL-MODE DUAL-BAND BANDPASS FILTER USING STEPPED-IMPEDANCE OPEN-LOOP RESONATORS AND CENTER-LOADED RESONATORS

作者：Yao Z; Wang C; Kim N Y^*

来源：Microwave and Optical Technology Letters, 2013, 55(12): 3000-3005.

DOI：10.1002/mop.27952

• dual-mode
• dual-band
• bandpass filter
• open-loop resonator
• center-loaded resonator
• stepped-impedance resonator

In this article, a compact dual-mode dual-band bandpass filter is proposed by using two modified stepped-impedance open-loop resonators and center-loaded bars. The dual-mode resonators are created by loading two center-loaded bars, and this process is investigated through dual-mode filter analysis. The external quality factor and the coupling coefficient is introduced and analyzed to optimize the proposed filter. A low insertion loss and high return loss dual-mode dual-band filter is designed and fabricated with a compact structure. Three transmission zeros are created near the passband, leading to a high selectivity. Two passbands are centered at 3.88 and 5.35 GHz with an insertion loss of -0.38 and -1.03 dB, respectively, and 3-dB fractional bandwidths of 12.4 and 8.6% are obtained. The measured return loss is higher than -24.28 and -19.33 dB at the two resonant frequencies, respectively. The simulated and measured results are in good agreement, which verifies the design methodology.

• 出版日期2013-12