Low noise magnetically tuned resonant circuit

Abstract From the Canadian patent

A magnetically tuned resonant circuit having improved noise performance includes a ferrimagnetic or gyromagnetic body such as a YIG sphere which is disposed within a r.f. structure. The r.f. structure is disposed between a pair of pole pieces of a biasing magnet and flux return path. Several techniques are described for reducing fluctuations in magnetic fields through the gyromagnetic body. The gyromagnetic body is isolated from conductive surfaces or, the bulk of conductive surfaces in the region adjacent to the magnetic body are reduced. Further a technique is, also described which provides a break in the electrical continuity around the r.f. structure. Each of these technique reduce the …