Systems and methods for using electroforming to manufacture fractal antennas

Abstract

One or more fractal antennas are produced in an electroforming circuit. A stainless steel on glass mandrel is covered with a dielectric in an inverse image of a fractal antenna to be formed. The portion of the stainless steel uncovered by the dielectric is chemically washed so that a fractal antenna formed thereon can be more efficiently removed. The mandrel is made a cathode in an electroforming circuit, which results in a fractal antenna being formed on the mandrel. The fractal antenna is separated from the mandrel and mounted on a rigid or semi-rigid substrate.

I claim:  
     
         1 . A method for producing a fractal antenna, comprising: 
 generating a photo-mask master of a fractal antenna;    using the photo-mask master to generate a mandrel;    electroforming a fractal antenna on the mandrel; and    separating the fractal antenna from the mandrel.    
     
     
         2 . The method as recited in  claim 1 , wherein the mandrel further comprises a dielectric on a stainless steel layer, the dielectric containing a negative image of the fractal antenna where there is no dielectric material.  
     
     
         3 . The method as recited in  claim 2 , wherein the dielectric is chosen from the following group: silicon carbide; silicon nitride; silicon oxide.  
     
     
         4 . The method as recited in  claim 1 , further comprising mounting the fractal antenna to a semi-rigid substrate.  
     
     
         5 . The method as recited in  claim 1 , further comprising mounting the fractal antenna to a rigid substrate.  
     
     
         6 . A method as recited in  claim 1 , wherein the electroforming a fractal antenna further comprises making the mandrel a cathode in an electroforming circuit having an electrolyte solution and an anode, the anode being formed from a metal to be deposited on the cathode-mandrel to form the fractal antenna, and the electrolyte solution containing a dissolved salt of the metal.  
     
     
         7 . A method as recited in  claim 1 , further comprising: 
 chemically cleaning the mandrel; and    re-using the mandrel to electroform a fractal antenna.    
     
     
         8 . An electroforming system, comprising: 
 an electrolyte solution containing salts of a metal used to form a fractal antenna;    an anode immersed in the electrolyte solution, the anode being made of the metal used to form the fractal antenna;    a cathode on which metal from the anode is deposited to form a fractal antenna when electricity is applied to the system; and    an electrical source to provide electricity to the system.    
     
     
         9 . A system as recited in  claim 8 , wherein the cathode further comprises a mandrel formed so that when metal is deposited on the mandrel, it is deposited in the shape of the fractal antenna to be formed.  
     
     
         10 . A system as recited in  claim 9 , wherein the mandrel further comprises a stainless steel layer having a dielectric thereon, the dielectric forming a negative image of the fractal antenna, so that when metal is deposited on the mandrel, only those portions not covered by the dielectric are plated.  
     
     
         11 . A system as recited in  claim 10 , wherein the dielectric is chosen from the following group: silicon carbide; silicon nitride; silicon oxide.  
     
     
         12 . A method of producing a mandrel for electroforming a fractal antenna, the method comprising: 
 providing an electrically-conductive layer on a substrate;    providing a patterned layer of an electrically-insulating material on the substrate, the patterned layer being formed so that portions of the electrically-conductive layer are exposed to form the shape of a fractal antenna; and    surface treating the exposed portions of the electrically-conductive layer to reduce adhesion of a subsequently applied metal.    
     
     
         13 . The method as recited in  claim 12 , wherein the substrate is a glass substrate and the electrically-conductive layer is stainless steel.  
     
     
         14 . The method as recited in  claim 12 , wherein the electrically-insulating layer is a silicon carbide dielectric.  
     
     
         15 . A reusable mandrel for producing multiple fractal antennas, comprising: 
 a substrate;    an electrically-conductive layer on the substrate;    an electrical insulator on the electrically-conductive layer, the electrical insulator patterned in such a way as to cover all of the electrically-conductive layer except for a portion having the shape of the fractal antennas to be produced; and    wherein a fractal antenna is formed in the shape of the pattern in the electrical insulator when the mandrel is used as a cathode in an electroforming circuit.    
     
     
         16 . The reusable mandrel as recited in  claim 15 , wherein the electrically-conductive layer further comprises stainless steel.  
     
     
         17 . The reusable mandrel as recited in  claim 15 , wherein the electrically-conductive layer is stainless steel and the electrical insulator further comprises one of the following: silicon carbide; silicon nitride; silicon oxide.  
     
     
         18 . The reusable mandrel as recited in  claim 15 , wherein the substrate further comprises glass.