RT info:eu-repo/semantics/article T1 Balanced quasi-elliptic-type dual-passband filters using planar transversal coupled-line sections and their digital modeling A1 Yang, Li A1 Malki, Mohamed A1 Muñoz Ferreras, José María A1 Gómez García, Roberto K1 Balanced filter K1 Bandpass filter (BPF) K1 Dual-band filter K1 Microstrip filter K1 Parallel coupled line K1 Planar filter K1 Signal-interference filter K1 Transmission zero (TZ) K1 Transversal section K1 Telecomunicaciones K1 Telecommunication AB A class of balanced dual-band bandpass filters (BPFs) with planar transversal-signal-interference coupled-line sections is reported. In their building balanced dual-band BPF stage under differential-mode excitation, a second-order quasi-elliptic-type dual-band bandpass filtering transfer function is obtained. Specifically, from the transversal interaction among their two open-ended and virtually-short-ended half-wavelength coupled-line paths, sharp-rejection differential-mode dual passbands with several out-of-band transmission zeros at both sides are realized. To attain high common-mode suppression levels within the differential-mode passbands, two open-ended line segments are connected at the symmetry plane of the devised balanced dual-band BPF stage. Moreover, higher-order schemes based on in-series-cascaded multi-stage designs to further increase differential-mode selectivity and in-band common-mode rejection are illustrated. The operational principles and parametric-analysis design rules of the engineered transversal-coupled-line-based balanced dual-band BPF approach are detailed. Additionally, for a rigorous interpretation of their zero/pole characteristics, a digital-modeling framework is applied to them to connect RF balanced filters with their discrete-time versions. For practical-validation purposes, a microstrip prototype of two-stage/fourth-order balanced dual-band BPF is built and tested. It exhibits measured differential-mode dual passbands with center frequencies of 1.464 GHz and 2.294 GHz, 3-dB fractional bandwidths of 8.74% and 9.68%, and in-band common-mode rejection levels above 23.16 dB and 31.36 dB, respectively. PB Cambridge University Press SN 1759-0787 YR 2022 FD 2022-06-24 LK http://hdl.handle.net/10017/55350 UL http://hdl.handle.net/10017/55350 LA eng NO European Commission DS MINDS@UW RD 29-mar-2024