Since I haven't yet received my copy of the original transmittal I sent on 22 January, it must have fallen into an electronic crack somewhere. Hence, here goes a second time. MLC
Gentlemen: Because of the intended lossy nature of the various ferrite bead formulations, the difference (if any) of the RF loss characteristics versus frequency as a function of the direct current (or more accurately, the flux density) in the bead is not well publicized (if reliably known at all). .....Another way to characterize this behavior might be to assess the loss factor of the material versus dc current and frequency and correlate this to the (generally published) permeability data. Can anyone supply me some data or direct me to some authoritative literature/papers on the subject? I have tested, characterized, and modeled specific beads planned for specific circuits and know the bead formulation, size, and temperature will all have their respective effects. However, is there an easier way to reliably execute a design without actual test characterization of a given circuit (and specific bead) configuration? Thank you for your time and consideration. Mike Conn Owner/Principal Consultant Mikon Consulting
