Methods related to junction ferrite devices having improved insertion loss performance

Abstract

Disclosed are methods related to junction ferrite devices having improved insertion loss performance. In some implementations, a method of fabricating a circulator includes providing a grounding plane having a first side and a second side, positioning a magnet on the first side of the grounding plane, and positioning a ferrite-based disk on the second side of the grounding plane, the ferrite-based disk including a metalized layer on a grounding surface such that the metalized layer is in electrical contact with the second side of the grounding plane. In some implementations, a method for fabricating a ferrite disk assembly for a radio-frequency circulator includes forming a ferrite-based disk that includes a ferrite center portion, and forming a metalized layer on a first surface of the disk to improve electrical contact between the first surface of the disk with an external contact surface. Optionally, the metalized layer can be a silver layer formed on the grounding surface of the disk and having a desired thickness.

1 . A method for fabricating a ferrite disk assembly for a radio-frequency circulator, the method comprising:
 forming a ferrite-based disk that includes a ferrite center portion; and   forming a metalized layer on a first surface of the disk to improve electrical contact between the first surface of the disk with an external contact surface.   
     
     
         2 . The method of  claim 1  further comprising forming a desired finish surface on the first surface of the disk prior to the metalized layer formation. 
     
     
         3 . The method of  claim 2  wherein forming the metalized layer includes depositing a film of metal using an ink deposition method. 
     
     
         4 . The method of  claim 3  wherein forming the metalized layer includes curing the deposited film of metal. 
     
     
         5 . The method of  claim 1  wherein forming the ferrite-based disk includes assembling a sintered rod inside a hollow cylinder, sintering the rod-and-cylinder assembly, and forming one or more disks from the sintered rod-and-cylinder assembly. 
     
     
         6 . The method of  claim 5  where the sintered rod is a ferrite rod and the hollow cylinder is a dielectric cylinder. 
     
     
         7 . The method of  claim 1  wherein forming the ferrite-based disk includes securing a dielectric ring about the ferrite center portion to define a disk assembly. 
     
     
         8 . The method of  claim 7  wherein securing the dielectric ring about the ferrite center portion includes using a co-firing technique to provide an adhesive-free joint between the dielectric ring and the ferrite center portion, such that the disk assembly can withstand temperatures in excess of 1000 degrees Celsius. 
     
     
         9 . The method of  claim 1  wherein forming the metalized layer includes forming a metalized layer having a thickness of about one to two skin depths. 
     
     
         10 . The method of  claim 1  wherein forming the metalized layer includes forming a silver layer. 
     
     
         11 . A method for improving insertion loss performance of a radio-frequency circulator, the method comprising:
 forming a ferrite-based disk that includes a ferrite center portion; and   forming a desired finish for a grounding surface on the disk, the finish selected to improve an electrical connection between the grounding surface and one or more metal structures, the desired finish having an average feature size on the grounding surface that is less than an average size resulting from a cut that yields the ferrite-based disk.   
     
     
         12 . The method of  claim 11  wherein the one or more metal structures includes a metalized layer formed on the grounding surface after forming the desired finish. 
     
     
         13 . The method of  claim 12  wherein the metalized layer is a silver layer. 
     
     
         14 . The method of  claim 12  wherein forming the metalized layer includes depositing a film of metal using an ink deposition method. 
     
     
         15 . The method of  claim 14  wherein forming the metalized layer includes curing the deposited film of metal. 
     
     
         16 . The method of  claim 11  wherein forming the ferrite-based disk includes assembling a sintered rod inside a hollow cylinder, sintering the rod-and-cylinder assembly, and forming one or more disks from the sintered rod-and-cylinder assembly. 
     
     
         17 . The method of  claim 16  where the sintered rod is a ferrite rod and the hollow cylinder is a dielectric cylinder. 
     
     
         18 . The method of  claim 11  wherein forming the ferrite-based disk includes securing a dielectric ring about the ferrite center portion to define a disk assembly. 
     
     
         19 . The method of  claim 18  wherein securing the dielectric ring about the ferrite center portion includes using a co-firing technique to provide an adhesive-free joint between the dielectric ring and the ferrite center portion, such that the disk assembly can withstand temperatures in excess of 1000 degrees Celsius. 
     
     
         20 . A method for fabricating a circulator, the method comprising:
 providing a grounding plane having a first side and a second side;   positioning a magnet on the first side of the grounding plane; and   positioning a ferrite-based disk on the second side of the grounding plane, the ferrite-based disk including a metalized layer on a grounding surface such that the metalized layer is in electrical contact with the second side of the grounding plane.