A survey of properties of latched non reciprocal ferrite phase shifters with cylindrical rods at 3, 5.5, 9.3 and 16 GHz

Experimental results of non reciprocal latched ferrite phase shifters are given in the frequency bands S, C, X, and Ku. The flux drive principle is used for the driver. The shape of the ferrite is for all examined cases a cylinder with an axial concentric hole for the switching wire of the driver. Two narrow flat strips are ground on the cylinder in order to achieve good contact with both broad walls of the rectangular waveguide in which the ferrite toroid is placed. The width of the waveguide over the length of the toroid is adjusted in such a way that the differential phase shift is independent of frequency over a bandwidth of at least 20%. In general, this width is smaller than the standard waveguide width. The height of this waveguide part is identical to the height between the two narrow flat strips and therefore just a little smaller than the diameter of the toroid. With the aid of matching transformers and waveguide tapers, the cross section of the ferrite loaded waveguide is brought to that of the standard waveguide. With this setup, the phase shift, the insertion loss, the temperature dependence of the phase shift, and the peak power capability of the phase shifter are measured. Various types of ferrite are examined, such as magnesium-manganese ferrite, lithium ferrite, and mixed garnets. The saturation magnetization value is selected in such a way that low-field losses are avoided.