Passive magnetic devices
A passive magnetic device (PMD) has a base electrode, a multi-port signal structure (MPSS), and a substrate therebetween. The MPSS has a central plate residing in a second plane and at least two port tabs spaced apart from one another and extending from the central plate. The substrate has a central portion that defines a mesh structure between the base electrode and the central plate of the multi-port signal structure. A plurality of magnetic pillars are provided within the mesh structure, wherein each of the plurality of the magnetic pillars are spaced apart from one another and surrounded by a corresponding portion of the mesh structure. The PMD may provide a magnetically self-biased device that may be used as a radio frequency (RF) circulator, an RF isolator, and the like.
1. A passive magnetic device comprising:
a base electrode;
multi-port signal structure comprising a central plate and at least two port tabs spaced apart from one another and extending from the central plate;
a substrate having a central portion that defines a mesh structure between the base electrode and the central plate of the multi-port signal structure; and
a plurality of magnetic pillars within the mesh structure, wherein the plurality of magnetic pillars are spaced apart from one another and surrounded by a corresponding portion of the mesh structure.
2. The passive magnetic device of claim 1 wherein the substrate and the central portion that defines the mesh structure are formed from silicon carbide.
3. The passive magnetic device of claim 1 wherein the substrate and the central portion that defines the mesh structure are formed from at least one of a group consisting of aluminum nitride and diamond.
4. The passive magnetic device of claim 1 wherein the plurality of magnetic pillars comprises at least one of a group consisting of iron, nickel, and cobalt.
5. The passive magnetic device of claim 1 wherein the plurality of magnetic pillars comprises iron.
6. The passive magnetic device of claim 1 wherein the plurality of magnetic pillars is formed from one of a group consisting of iron carbonate, an iron carbonate alloy, iron nickel, and an iron nickel alloy.
7. The passive magnetic device of claim 1 wherein the plurality of magnetic pillars comprise magnetic nanoparticles.
8. The passive magnetic device of claim 1 wherein the plurality of magnetic pillars is formed from a first material, the mesh structure is formed from a second material, and a thermal conductivity of the second material is at least five times greater than a thermal conductivity of the first material.
9. The passive magnetic device of claim 8 wherein the substrate is formed from the second material.
10. The passive magnetic device of claim 1 wherein:
the substrate and the central portion that defines the mesh structure are formed from silicon carbide; and
the plurality of magnetic pillars is formed from a first material; and
a thermal conductivity of the silicon carbide is at least five times greater than a thermal conductivity of the first material.
11. The passive magnetic device of claim 1 wherein each of the plurality of magnetic pillars are columnar-shaped and have a nominal diameter of less than 100 micrometers.
12. The passive magnetic device of claim 1 wherein the plurality of magnetic pillars comprises at least nine magnetic pillars.
13. The passive magnetic device of claim 1 wherein a volume of the plurality of magnetic pillars is greater than a volume of the mesh structure.