Magnetostrictive rod filters
AssigneeSociete Anonyme de Telecommunications
InventorRene G. Deschamps
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Abstract
Magnetostrictive rod filter whose attenuation versus frequency curve has a resonance as the conventional magnetostrictive rod filters but also a pole at a frequency near the resonance frequency. The filter comprises a freely vibrating magnetostrictive rod, two windings symmetrically located with respect to the rod center and surrounding the rod, ferrimagnetic material sheaths surrounding the windings except on the parts thereof facing the rod and means for applying a d.c. magnetic field to the rod. The pole of the attenuation curve is due to a demagnetizing field created by portions of the rod externally projecting beyond the windings and by apertures in those parts of the sheaths facing these rod projecting portions.
Claims3
A magnetostrictive rod filter comprising:
- a freely vibrating magnetostrictive rod;
- an input winding and an output winding placed on either side of the center of and surrounding said rod;
- ferrimagnetic material sheaths respectively surrounding said input and output windings;
- permanent magnetic field producing means for applying a longitudinal d.c. magnetic field to said rod;
- a demagnetizing field producing means at each end of said rod inducing a voltage respectively in said input and output winding;
- said demagnetizing field producing means consisting of the portions of said rod externally projecting beyond said windings and by apertures in the part of said ferrimagnetic material sheaths facing the projecting portions of said rod.
Dependencies are inferred from the claim text.