Title :
Narrow bandpass filters using dual-behavior resonators
Author :
Quendo, Cedric ; Rius, Eric ; Person, Christian
fDate :
3/1/2003 12:00:00 AM
Abstract :
This paper reports on a new concept of narrow bandpass filters leading to perfectly controlled electrical responses within both the required operating bandwidth and adjacent undesired bands. A specific topology is considered for such a "global synthesis": in comparison with conventional filter performances, it provides significant improvements in terms of rejection control. The attenuated frequencies are each located apart from the bandpass frequencies and controlled by means of n transmission zeros introduced through original dual-behavior resonators (DBRs). These resonators are based on the association of different parallel open-ended stubs and allow the designer to independently control the in-band and out-of-band responses of the filter. A global synthesis approach is also discussed on a simplified architecture based on stepped impedance stubs, and the experimental results shown clearly validate the proposed concept. This simplification reduces the number of degrees of freedom when designing a DBR, and consequently the two transmission zeros become dependent.
Keywords :
band-pass filters; linear network synthesis; microstrip filters; microstrip resonators; microwave filters; passive filters; poles and zeros; resonator filters; transmission line theory; dual-behavior resonators; filter synthesis; global synthesis approach; in-band responses; microstrip technology; microwave bandpass filter; narrow bandpass filters; out-of-band responses; parallel open-ended stubs; perfectly controlled electrical responses; rejection control; stepped impedance stubs; transmission zeros; Band pass filters; Bandwidth; Costs; Degradation; Filtering theory; Microwave filters; Planar waveguides; Radio frequency; Resonator filters; Topology;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
DOI :
10.1109/TMTT.2003.808729