Dual-Behavior Resonator-Based Fully Reconfigurable Input Reflectionless Bandpass Filters

• Published in: IEEE microwave and wireless components letters Vol. 29; no. 1; pp. 35 - 37
• Main Authors: Gomez-Garcia, Roberto, Munoz-Ferreras, Jose-Maria, Psychogiou, Dimitra
• Format: Journal Article
• Language: English
• Published: IEEE 01.01.2019
• Subjects: Absorptive filter; Band-pass filters; bandpass filter (BPF); Bandwidth; complementary duplexer; Microstrip; microstrip filter; planar filter; Radio frequency; reconfigurable filter; reflectionless filter; Resonant frequency; Transfer functions; transmission zero (TZ); tunable filter; Tuning
• ISSN: 1531-1309; 1558-1764
• DOI: 10.1109/LMWC.2018.2884151

A class of input reflectionless dual-behavior resonator (DBR)-based bandpass filters (BPFs) with reconfigurable center frequency, bandwidth, out-of-band attenuation, and intrinsic switching-off capabilities is reported. They exploit a complementary-duplexer approach, in which the resistively terminated bandstop-filter (BSF) channel dissipates the RF input signal energy that is not transmitted by the main BPF channel in its out-of-band region. Spectral reconfiguration is realized through the synchronous tuning of the counterpart resonators in the DBR-based BPF and BSF channels-i.e., without variable couplings-which results in a dynamic transmission-zero (TZ) reallocation process. The theoretical analysis of the first-order section and design examples for higher order schemes are presented. Furthermore, for experimental-validation purposes, a microstrip prototype that can be tuned within the frequency range 1.3-2 GHz is manufactured and characterized.