Materials, devices and methods related to below-resonance radio-frequency circulators and isolators

摘要

Materials, devices and methods related to below-resonance radio-frequency (RF) circulators and isolators. In some embodiments, a circulator can include a conductor having a plurality of signal ports, and one or more magnets configured to provide a magnetic field. The circulator can further include one or more ferrite disks implemented relative to the conductor and the one or more magnets so that an RF signal can be routed selectively among the signal ports due to the magnetic field. Each of the one or more ferrite disks can include synthetic garnet material having dodecahedral sites, octahedral sites and tetrahedral sites, with bismuth (Bi) occupying at least some of the dodecahedral sites, and aluminum (Al) occupying at least some of the tetrahedral sites. Such synthetic garnet material can be represented by a formula Y3-x-2y−zBixCa2y+zFe5-y-z-aVyZrzAlaO12. In some embodiments, x≦1.4, y≦0.7, z≦0.7, and a≦0.75.

主权项

1. A synthetic garnet material comprising a structure represented by the formula Y3-x-2y−zBixCa2y+zFe5-y-z-aVyZrzAlaO12, bismuth occupying x formula units of dodecahedral sites, zirconium occupying z formula units of octahedral sites, vanadium occupying y formula units of tetrahedral sites, calcium occupying 2y+z formula units of the dodecahedral sites to compensate for a valency imbalance resulting from the presence of zirconium and vanadium, aluminum occupying a formula units of the tetrahedral sites while having the octahedral sites substantially free of aluminum, the quantity a being greater than zero, such that saturation magnetization of the material decreases in a substantially linear manner as the quantity a increases to an upper limit value of at least 0.6.