Open AccessCompact and independently‐design tri‐band bandpass filter with bandwidth and return loss control
Author(s) -
Lu Di,
Barker Nicolas Scott,
Tang Xiao H.
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.2016.3247
Subject(s) - passband , band pass filter , return loss , bandwidth (computing) , resonator , prototype filter , electronic engineering , computer science , physics , control theory (sociology) , telecommunications , optoelectronics , engineering , low pass filter , antenna (radio) , control (management) , artificial intelligence
A compact tri‐band bandpass filter with high controllability is proposed using two multipath λ /4 resonator‐loaded resonators (MRLRs). Separated electric and magnetic coupling (SEMC) is applied into the filter, which introduces multiple transmission zeros (TZs) and enables each bandwidth to be separately controllable. In addition, both the return loss control and centre frequency (CF) control are implemented by changing the physical dimension of MRLRs. Owing to the usage of SEMC, three TZs can be, respectively, allocated either below or above the associated passbands. Moreover, the third passband can be far away from the first passband, e.g. 1.57/5.8 GHz ( f 1 /3.7 f 1 ), when each passband is independently designed. A filter example operating at 1.57/3.5/5.8 GHz (GPS/WiMAX/WLAN) with a size of 0.08 λ g × 0.14 λ g is designed and fabricated. Good agreement between simulation and measurement is achieved to validate its performance.