An important component in many microwave and mm-wave systems is the isolator or circulator. We use permanently magnetised ferrite materials to construct quasi optical Faraday rotators (QOFRs) which can be used to make both isolators and circulators. These devices have very high performance and are a key enabling technology for many mm-wave systems. Construction of good devices requires detailed knowledge of the ferrite material, the dielectric matching layers and any adhesives involved.



The picture above shows what is probably the largest quasi-optical isolator ever! The device was designed for a 35GHz imaging system constructed by DERA (now QinetiQ) and is a fairly extreme example of the types of device we can manufacture.