Open AccessMicrostrip Lowpass Filter with Very SharpTransition Band Using T‐Shaped, Patch, and Stepped Impedance Resonators
Author(s) -
Hayati Mohsen,
Sheikhi Akram
Publication year - 2013
Publication title -
etri journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.295
H-Index - 46
eISSN - 2233-7326
pISSN - 1225-6463
DOI - 10.4218/etrij.13.0212.0307
Subject(s) - stopband , resonator , microstrip , low pass filter , materials science , transition band , bandwidth (computing) , capacitance , filter (signal processing) , distributed element filter , attenuation , electrical impedance , acoustics , optoelectronics , m derived filter , prototype filter , optics , physics , electrical engineering , telecommunications , engineering , electrode , quantum mechanics
A compact microstrip lowpass filter (LPF) with an elliptic function response is proposed. A high equivalent capacitance and inductance between the structures of the resonator result in the sharp transition band of 0.04 GHz from 4 GHz to 4.04 GHz with an attenuation level of −3 dB and −20 dB, respectively. To improve the LPF rejection band, multiple open stubs are connected to the proposed resonator. A filter with a 3‐dB cut‐off frequency at 4 GHz is designed, fabricated, and measured, and agreement between the measured and simulated results is achieved. The results show that a stopband bandwidth of 131% with a suppression level better than −20 dB is obtained while achieving a compact size with a wide stopband.