Title :
Analysis of ferrite beads for RF isolation on straight wire conductors
Author :
Saario, S.A. ; Thiel, D.V. ; O´Keefe, Steven G. ; Lu, Jun W.
Author_Institution :
Sch. of Microelectron. Eng., Griffith Univ., Nathan, Qld., Australia
fDate :
7/31/1997 12:00:00 AM
Abstract :
Ferrite beads used for the suppression of electromagnetic interference (EMI) were analysed using the finite difference time domain (FDTD) method. The presence of the bead results in reflected current, cable radiation and resonant characteristics which significantly affect the ability to suppress currents uniformly over a wide frequency range. A typical low conductivity ferrite bead (σ=1 μS/m, εr =1, μr=100), with length L=21 mm and outer diameter D=11 mm is shown to be a poor isolator at 1.03, 1.71, 2.37 and 2.93 GHz due to this resonance phenomenon. The effective suppression of EMI depends on the properties and dimensions of the ferrite bead in addition to the frequency of operation
Keywords :
UHF devices; conductors (electric); ferrite devices; finite difference time-domain analysis; interference suppression; radiofrequency interference; 1.03 to 2.93 GHz; EMI suppression; FDTD method; RF isolation; cable radiation; electromagnetic interference; ferrite beads; finite difference time domain method; reflected current; resonant characteristics; straight wire conductors;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:19970934
