Asymmetric Dual-Mode FSIW Filters with High Stopband Rejection

Citation
24th International Microwave and Radar Conference (MIKON 2022)
Contribution to Conference
24th International Microwave and Radar Conference, MIKON 2022  
Publisher DOI
10.23919/MIKON54314.2022.9924918
Scopus ID
2-s2.0-85142027375
This contribution discusses means to achieve high stopband rejection in bandpass filters. For compactness, the latter rely on dual-mode operation and a realization in folded substrate integrated waveguide (FSIW) technology. To obtain an asymmetric second-order response with two transmission zeros (TZs) in the lower stopband, the design combines a doublet of two resonant modes and a non-resonating node (NRN) with different perturbation means. The validity of the approach is demonstrated around 20GHz with two second-order filters with differently spaced TZs and a cascaded fourth-order version. These feature a -10dB reflection bandwidth (insertion loss) of 1.1GHz (1.9dB), 1.2GHz (2.0dB), and 1.6GHz (3.3dB), respectively. With stopband rejection ratios between 39dB and 58dB, the filters satisfy image noise suppression requirements in satellite communication (SatCom) receivers. Their surface area of about 5x6mm2 and less complies with the severe spatial constraints in SatCom phased arrays.
Subjects
Asymmetric
doublet
dual-mode
filter
folded substrate integrated waveguide (FSIW)
image rejection
non-resonating node (NRN)
phased array
transmission zero (TZ)