Novel Wideband Bandpass Filters Using Double-Sided Quasi-SSPPs Transmission Line

作者：Feng, Wenjie; Shi, Suyang; Yin, Shuoying; Zhu, Haoshen^*; Shi, Yongrong^*; Che, Wenquan^*

来源：IEEE Transactions on Circuits and Systems II: Express Briefs , 2022, 69(7): 3174-3178.

DOI：10.1109/TCSII.2022.3169550

• Calibration
• Couplers
• Couplings
• Phased arrays
• Apertures
• Wideband
• Microstrip
• Bandpass filter
• double-sided parallel-stripline (DSPSL)
• spoof surface plasmon polaritons (SSPPs)

In this brief, two wideband bandpass filters using a novel double-row staggered double-sided quasi-SSPPs transmission line are proposed. By loading U-shaped cells symmetrically, a transmission zero can be introduced into the original operating frequency band, which forms a high out-of-band suppression wideband bandpass filter. The structure can draw an analogy with double-sided parallel stripline, and the equivalent circuit model of microstrip line can be constructed to assist analysis and design. The passband selectivity can be further improved when the number of U-shaped cells is increased from 3 to 5. The measured result of 3-dB fractional bandwidth is 18.9 % (frequency 11.4 GHz), and the in-band return loss is greater than 10.2 dB. In addition, the out-of-band suppression is greater than 20 dB in the lower stopband (from 6.18 GHz to 10.12 GHz) and the upper stopband (from 12.78 GHz to 19 GHz).

• 单位
  南京理工大学; 南京航空航天大学