Arc plasma sprayed C-band lithium ferrite phase shifters

The arc plasma spraying (APS) technology has demonstrated the capability of being economical in the fabrication of non-reciprocal ferrite phase shifter elements. It has been possible to arc plasma spray a C-band element in less than 10 minutes using a commercial spray dried lithium ferrite powder. This paper discusses the material properties (coercive force, remanence, and microwave loss) of the deposited lithium ferrite and the device performance (differential phase shift and insertion loss) of arc plasma fabricated phase shifter elements. The effects of stresses, generated by a mismatch of thermal coefficient of expansion between the ferrite and the dielectric are also discussed.