Disclosed herein are embodiments of low temperature co-fireable scheelite materials which can be used in combination with high dielectric materials, such as nickel zinc ferrite, to form composite structures, in particular for isolators and circulators for radiofrequency components. In some embodiments, the scheelite material can include aluminum oxide for temperature expansion regulation.

Disclosed herein are embodiments of low temperature co-fireable dielectric materials which can be used in conjunction with high dielectric materials to form composite structures, in particular for isolators and circulators for radiofrequency components. Embodiments of the low temperature co-fireable dielectric materials can be scheelite or garnet structures, for example, bismuth vanadate. Adhesives and/or glue is not necessary for the formation of the isolators and circulators.

A double-disc structure for self-biased circulators monolithically integrated on semiconductors is provided. A self-based circulator is attractive due to the great reduction in its size and weight compared to conventional circulators which have bulk permanent magnets. The development of miniaturized self-biased circulators enables monolithic integration of such circulators directly into monolithic integrated circuits (e.g., monolithic microwave integrated circuits (MMICs)) on a single chip and opens the door to full-duplex communication in radio frequency (RF) bands higher than Ka band, without suffering from the additional losses through connectors. This disclosure demonstrates a new double-disc structure by using two self-biased discs in a circulator device, which greatly improve its insertion loss, isolation, bandwidth, and power handling capability.

A broadband microstrip ferrite circulator or isolator includes a carrier. The broadband microstrip ferrite circulator or isolator further includes a dielectric substrate having an opening therein. The broadband microstrip ferrite circulator or isolator further includes a ferrite disc positioned within the opening of the dielectric substrate. The broadband microstrip ferrite circulator or isolator further includes a conductor having three contacts extending therefrom, the conductor being positioned on the ferrite disc. The broadband microstrip ferrite circulator or isolator further includes a magnet. The broadband microstrip ferrite circulator or isolator further includes a spacer positioned between the conductor and the magnet.

A broadband microstrip ferrite circulator or isolator includes a carrier. The broadband microstrip ferrite circulator or isolator further includes a dielectric substrate having an opening therein. The broadband microstrip ferrite circulator or isolator further includes a ferrite disc positioned within the opening of the dielectric substrate. The broadband microstrip ferrite circulator or isolator further includes a conductor having three contacts extending therefrom, the conductor being positioned on the ferrite disc. The broadband microstrip ferrite circulator or isolator further includes a magnet. The broadband microstrip ferrite circulator or isolator further includes a spacer positioned between the conductor and the magnet.

A differential circulator comprises first and second magnets, a ground plane, a first three-port junction conductor disposed between the first magnet and the ground plane, and a second three-port junction conductor disposed between the second magnet and the ground plane. The first three-port junction conductor and the second three-port junction conductor are in the same magnetic circuit including the first and second magnets to provide substantially same pass characteristics to radio frequency signals passing through the first three-port junction conductor and the second three-port junction conductor.

A differential circulator comprises first and second magnets, a ground plane, a first three-port junction conductor disposed between the first magnet and the ground plane, and a second three-port junction conductor disposed between the second magnet and the ground plane. The first three-port junction conductor and the second three-port junction conductor are in the same magnetic circuit including the first and second magnets to provide substantially same pass characteristics to radio frequency signals passing through the first three-port junction conductor and the second three-port junction conductor.

The disclosed technology relates to a ceramic composition and an article formed therefrom. A ceramic article for radio frequency applications is formed of a ceramic material having a chemical formula represented by: Bi.sub.1.0+aY.sub.2.0-a-x-2yCa.sub.x+2yFe.sub.5-x-yM.sup.IV.sub.xV.sub.yO.sub.12 or Bi.sub.1.0+aY.sub.2.0-a-2yCa.sub.2yFe.sub.5-y-zV.sub.yIn.sub.zO.sub.12. The ceramic material has a composition such that a normalized change in saturation magnetization (Δ4πMs), defined as Δ4πMs=[(4πMs at 20° C.)-(4πMs at 120° C.)]/(4πMs at 20° C.), is less than about 0.35.

The disclosed technology relates to a ceramic composition and an article formed therefrom. A ceramic article for radio frequency applications is formed of a ceramic material having a chemical formula represented by: Bi.sub.1.0+aY.sub.2.0-a-x-2yCa.sub.x+2yFe.sub.5-x-yM.sup.IV.sub.xV.sub.yO.sub.12 or Bi.sub.1.0+aY.sub.2.0-a-2yCa.sub.2yFe.sub.5-y-zV.sub.yIn.sub.zO.sub.12. The ceramic material has a composition such that a normalized change in saturation magnetization (Δ4πMs), defined as Δ4πMs=[(4πMs at 20° C.)-(4πMs at 120° C.)]/(4πMs at 20° C.), is less than about 0.35.

A circulator comprising a grounding plane including a first side and a second side, a magnet disposed on the first side of the grounding plane, a ferrite-based disk disposed on the second side of the grounding plane, and a conductor disposed on a side of the ferrite-based disk opposing the grounding plane. The conductor includes an elongate portion and the elongate portion has a distal end section projecting inwardly adjacent to a side of the magnet opposing the grounding plane. The circulator comprises a circulator housing including a plurality of side portions. The side portions have a first section and a second section, the second section extending further around a periphery of the housing than the first section such that a gap between neighboring first sections is wider than a gap between neighboring second sections.