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A microstrip bandpass filter with tunable bandwidth and center frequency
Author(s) -
Chen Anrong,
Yang Tao
Publication year - 2021
Publication title -
microwave and optical technology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 76
eISSN - 1098-2760
pISSN - 0895-2477
DOI - 10.1002/mop.32909
Subject(s) - center frequency , bandwidth (computing) , band pass filter , resonator , materials science , cascade , optoelectronics , microwave , microstrip , insertion loss , electronic engineering , electrical engineering , engineering , telecommunications , chemical engineering
This paper presents a bandwidth and center frequency tunable bandpass filter with wide tuning range. The proposed filter employs two cascade cross‐shaped resonators. The cross‐shaped resonator can generate two independent tunable transmission zeros by introducing two microwave varactors. The center frequency and bandwidth can be tuned by adjusting the DC bias voltages applied to the varactors. For demonstration, a filter example was designed, fabricated and measured. The tuning 3‐dB bandwidth from 20% to 30% is achieved when the center frequency is tuned from 3.5 to 5 GHz. Meanwhile the insertion loss is less than 4 dB with a high selectivity. The size of the filter is 0.32 λ g × 0.36 λ g where λ g is the guided‐wavelength at the center frequency.