Patent ID: 11881638
Assignee: PREMO, SA
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 9:
10. A method of producing the ultra-low profile low frequency antenna of claim 1 comprising:
obtaining a monolithic, flattened drum-like shape magnetic core by:
compacting in a mold powder of soft-magnetic non-electro conductive material shaping the magnetic core including a flat central region and four corner protuberances spaced apart to each other around said central region, said corner protuberances defining therebetween a X-coil winding channel surrounding the central region around the X-axis (X), and a Y-coil winding channel surrounding the central region around a Y-axis (Y);
creating a Z-coil winding channel surrounding the magnetic core around the Z-axis (Z) by a sawing process, said Z-coil winding channel being defined by a discontinuous groove confined between two surfaces, said discontinuous groove including four partial grooves each included in one of the corner protuberances;
oven-sintering the magnetic core producing its crystallization, shrinking and hardening;
arranging a X-coil (DX) wound around the X-axis (X) contained within the X-coil winding channel, a Y-coil (DY) wound around the Y-axis (Y) contained within the Y-coil winding channel, and a Z-coil (DZ) wound around the Z-axis (Z) contained within the Z-coil winding channel (12Z); and
connecting a conductive wire entry and a conductive wire exit of each of said X-coil, Y-coil and Z-coil to a respective connection terminal,
wherein each of the four partial grooves of the magnetic core and previous to the oven-sintering process has a trapezial cross section in a radial sectional plane coincident with the Z-axis (Z), said trapezial cross section being produced by a tapered saw during the sawing process, and being said trapezial cross section defined to become a rectangular cross section after the crystallization, shrinking and hardening.