Rare earth reduced garnet systems and related microwave applications

Abstract

Disclosed are synthetic garnets and related devices that can be used in radio-frequency (RF) applications. In some embodiments, such RF devices can include garnets having reduced or substantially nil Yttrium or other rare earth metals. Such garnets can be configured to yield high dielectric constants, and ferrite devices, such as TM-mode circulators/isolators, formed from such garnets can benefit from reduced dimensions. Further, reduced or nil rare earth content of such garnets can allow cost-effective fabrication of ferrite-based RF devices. In some embodiments, such ferrite devices can include other desirable properties such as low magnetic resonance linewidths. Examples of fabrication methods and RF-related properties are also disclosed.

1 . (canceled) 
     
     
         2 . A modified synthetic garnet material comprising:
 a vanadium-doped garnet represented by the formula Y 2.15−2x Bi 0.5 Ca 0.35+2x Zr 0.35 V x Fe 4.65−x O 12 , x being greater than or equal to 0.1 and less than or equal to 0.8, the vanadium being in a tetrahedral site of the garnet and calcium charge balancing the vanadium.   
     
     
         3 . The modified synthetic garnet material of  claim 2  wherein x is less than or equal to 0.5. 
     
     
         4 . The modified synthetic garnet material of  claim 3  wherein x is 0.5. 
     
     
         5 . The modified synthetic garnet material of  claim 4  wherein a 3 dB linewidth of the modified synthetic garnet material is about 50. 
     
     
         6 . The modified synthetic garnet material of  claim 2  wherein a dielectric constant and a density of the modified synthetic garnet material remains substantially the same with changing values of x. 
     
     
         7 . The modified synthetic garnet material of  claim 2  wherein a density of the modified synthetic garnet material is about 50. 
     
     
         8 . The modified synthetic garnet material of  claim 2  wherein a dielectric constant of the modified synthetic garnet material is below 25. 
     
     
         9 . The modified synthetic garnet material of  claim 2  wherein a 4 PiMs of the modified synthetic garnet material decreases with increasing values of x. 
     
     
         10 . A method of modifying a garnet material, the method comprising:
 substituting at least some iron from a garnet material with vanadium to form a synthetic garnet material having a composition Y 2.15−2x Bi 0.5 Ca 0.35+2x Zr 0.35 V x Fe 4.65−x O 12 , x being greater than or equal to 0.1 and less than or equal to 0.8, the vanadium being added to a tetrahedral site of the garnet.   
     
     
         11 . The method of  claim 10  further comprising forming a radiofrequency component from the synthetic garnet material. 
     
     
         12 . The method of  claim 10  wherein the radiofrequency component is a circulator. 
     
     
         13 . The method of  claim 10  wherein x is less than or equal to 0.5. 
     
     
         14 . The method of  claim 13  wherein x is 0.5. 
     
     
         15 . The method of  claim 10  further comprising mixing raw materials to form the garnet material. 
     
     
         16 . The method of  claim 10  further comprising heat treating the synthetic garnet material at a temperature of between 800 and 1000° C. 
     
     
         17 . A radiofrequency system comprising:
 at least one circulator including a vanadium-doped garnet represented by the formula Y 2.15−2x Bi 0.5 Ca 0.35+2x Zr 0.35 V x Fe 4.65−x O 12 , x being greater than or equal to 0.1 and less than or equal to 0.8, the vanadium being added to a tetrahedral site of the garnet.   
     
     
         18 . The radiofrequency system of  claim 17  wherein the circulator is incorporated into an antenna. 
     
     
         19 . The radiofrequency system of  claim 17  wherein the circulator is incorporated into a base station. 
     
     
         20 . The radiofrequency system of  claim 17  wherein x is less than or equal to 0.5. 
     
     
         21 . The radiofrequency system of  claim 20  wherein x is 0.5.