Open AccessStub‐loaded‐based bandpass filters with dynamically‐controlled in‐band notches
Author(s) -
Psychogiou D.,
GómezGarcía R.,
Peroulis D.
Publication year - 2016
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
eISSN - 1350-911X
pISSN - 0013-5194
DOI - 10.1049/el.2016.1307
Subject(s) - passband , band pass filter , stub (electronics) , resonator , out of band management , bandwidth (computing) , stopband , electronic engineering , microstrip , attenuation , materials science , computer science , physics , optoelectronics , optics , engineering , telecommunications , computer network , network architecture , network management station
The RF design of stub‐loaded‐based wide‐band bandpass filters (BPFs) with multiple tunable rejection bands in their transmission range is presented. The proposed concept exploits the replacement of the short‐circuited resonant stubs of the stub‐loaded‐based BPF with multi‐band bandstop (BS) sections. Each multi‐frequency BS section is formed by several in‐parallel‐cascaded 90°‐long stubs that are terminated by frequency‐agile resonators so that each of them results in an independently‐controlled transmission zero. In this manner, a plurality of high‐order reflective‐type rejection bands can be created and arbitrarily controlled. Further operational characteristics include: (i) scalability to any number of rejection bands and degree of selectivity, (ii) independent tuning of each notch without any influence on the remaining ones, and (iii) spectral‐merging of multiple stopbands to increase their bandwidth (BW) and enable controllability of the number of active notches in the passband. The aforementioned principles are experimentally validated through a prototype that exhibits a wide‐band (fractional BW: 68%), low‐loss (<0.7 dB) passband at 1000 MHz and two high‐attenuation (>60 dB) notches that can be independently tuned within the 870–1150 MHz range.