Open AccessHigh performance LPF Structure with sharp roll‐off and low VSWR
Author(s) -
Mousavi S.M.H.,
Makki S.V.A.,
Hooshangi Sh.,
Alirezaee Sh.,
Siahkamari H.,
Ahmadi M.
Publication year - 2015
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.2015.2329
Subject(s) - stopband , standing wave ratio , microstrip , resonator , low pass filter , bandwidth (computing) , insertion loss , materials science , electrical impedance , transmission line , figure of merit , acoustics , optics , optoelectronics , electrical engineering , physics , engineering , telecommunications , microstrip antenna , antenna (radio)
A symmetrical compact microstrip lowpass filter (LPF) with ultra‐wide rejection band and low voltage standing wave ratio (VSWR) using a novel structure of stepped impedance and butterfly‐shaped resonators is presented and fabricated. The LPF has a 3 dB cut‐off frequency at 1.513 GHz. The series structure of the butterfly‐shaped resonators result in a high roll‐off rate of 187.8 dB/GHz. By generating multiple transmission zeros, a wide stopband (with 35 dB rejection degree) is achieved. To reach a small circuit, the bended transmission line is properly utilised. Moreover, 171% relative stopband bandwidth and dimensions of 0.087 λ g × 0.157 λ g ( λ g is the guided wavelength at 1.513 GHz) are other specifications of this LPF. In addition, an acceptable match is obtained between the simulated and measured responses. In the end, the LPF achieves a high figure‐of‐merit of 82288.