Single crystal hexaferrite phase shifter at Ka band

A phase shifter was fabricated from a scandium doped M-type (SCM) barium hexaferrite single crystal substrate, and tested over microwave frequencies from 20 to 40 GHz and bias magnetic fields from 0 to 2 kOe. At a microwave frequency of 40 GHz and bias magnetic field of 1.3 kOe, the differential phase-shift rate was 42°/kOe mm and the loss rate was 0.7 dB/mm. The phase shifter utilized the large uniaxial anisotropy field inherent in ScM single crystals, where the crystallographic c axis and the magnetic bias field were parallel to each other and in the substrate plane. The performance of the phase shifter was modeled by the conjugate method for transmission electron microscopy wave and compared with experimental results.