Nanocomposite rf lens and radome

Abstract

A method of additively manufacturing a composite article with tuned impedance and refractive-index in three dimensions. The method includes providing a ferrite feedstock. The ferrite feedstock is loaded with ferrite particles. The method further includes depositing and curing the ferrite feedstock. Therein a composite article is formed.

1 - 20 . (Canceled) 
     
     
         21 . A composite article comprising:
 a cured or thermoplastic ferrite-and-polymer feedstock including a polymer host loaded with ferrite ceramic, the cured or thermoplastic ferrite-and-polymer feedstock arranged in a predetermined geometry so as to impart a desired impedance or refractive index to the composite article in three dimensions.   
     
     
         22 . The composite article of  claim 21  wherein the cured or thermoplastic ferrite-and-polymer feedstock is a cured ferrite-and-polymer feedstock. 
     
     
         23 . The composite article of  claim 21  wherein the cured or thermoplastic ferrite-and-polymer feedstock is a thermoplastic ferrite-and-polymer feedstock. 
     
     
         24 . The composite article of  claim 21  wherein the ferrite-and-polymer feedstock includes one or more of polyamide-6, polyamide-12, epoxy, tricyclodecane dimethanol dimethacrylate (TCMDA), polylactic acid, polystyrene, polyurethane, and wherein the ferrite ceramic includes a plurality of ferrite nanoparticles. 
     
     
         25 . The composite article of  claim 24  wherein the plurality of ferrite nanoparticles comprise at least 1 volume percent and up to 50 volume percent of the cured or thermoplastic ferrite-and-polymer feedstock. 
     
     
         26 . The composite article of  claim 24  wherein each of the plurality of ferrite nanoparticles has a size corresponding to a single magnetic domain. 
     
     
         27 . The composite article of  claim 24  wherein each of the plurality of ferrite nanoparticles is surface-functionalized. 
     
     
         28 . The composite article of  claim 21  wherein the ferrite ceramic includes one or more of a spinel ferrite, hexaferrite, garnet, and perovskite ceramic. 
     
     
         29 . The composite article of  claim 21  further comprising a structural material arranged on and/or around the cured or thermoplastic ferrite-and-polymer feedstock. 
     
     
         30 . The composite article of  claim 29  wherein the structural material comprises a cured or thermoplastic structural feedstock including a thermoplastic or cured polymer. 
     
     
         31 . The composite article of  claim 30  wherein the polymer is a UV-cured polymer. 
     
     
         32 . The composite article of  claim 21  wherein the cured or thermoplastic structural feedstock is chemically compatible with the cured or thermoplastic ferrite-and-polymer feedstock, and wherein the cured or thermoplastic structural and ferrite-and-polymer feedstocks define a local concentration change in ferrite loading and a gradient of the ferrite loading in the three dimensions. 
     
     
         33 . The composite article of  claim 32 , wherein the local concentration change is greater than 1%. 
     
     
         34 . The composite article of  claim 32  wherein the cured or thermoplastic structural feedstock is arranged as a patterned matrix. 
     
     
         35 . The composite article of  claim 34 , wherein the patterned matrix has gaps that vary in size thereby increasing or decreasing the impedance. 
     
     
         36 . The composite article of  claim 35  wherein the composite article is configured to receive electromagnetic radiation of a wavelength, and wherein the gaps are less than one-tenth of the wavelength. 
     
     
         37 . The composite article of  claim 21 , wherein the composite article is a radio-frequency or millimeter wavelength lens. 
     
     
         38 . The composite article of  claim 21 , wherein the composite article is one or more of a radome with impedance matched to surrounding free space, a waveguide, a waveguide-based transmission or receiving structure, or an antenna. 
     
     
         39 . The composite article of  claim 21 , wherein the composite article is a curved article. 
     
     
         40 . The composite article of  claim 21 , wherein the composite article comprises an A sandwich, B sandwich, C sandwich, or hybrid sandwich. 
     
     
         41 . The composite article of  claim 29  wherein the structural material includes one or more of polyamide-12, polyamide-6, polystyrene, polyurethane, polyethylene, acrylonitrile butadiene styrene, polypropylene, tricyclodecanedimethanol diacrylate, neopentyl glycol diacrylate, diethyleneglycol diacrylate, 1,6-hexanediol diacrylate, polycarbonate, and polyetherimide. 
     
     
         42 . The composite article of  claim 29  wherein the structural material includes acrylonitrile butadiene styrene. 
     
     
         43 . The composite article of  claim 29  wherein a non-ferrite portion of the ferrite-and-polymer material comprises the structural material.