High Performance Compact Microstripline Phase Shifter at C-Band Using Yttrium Iron Garnet

We report the fabrication of planar microstripline reciprocal phase shifter using a bulk Yttrium Iron Garnet (YIG) material. The propagation direction of the microstripline and magnetization direction of the YIG is collinear, and the length of the microstripline and the YIG was 50 mm in length. The proposed design shows large differential phase shifts of 100 degrees for applied magnetic fields varying from 0 to 0.56 times 10⁴ A/m over the frequency range of 1.2 GHz between 5.4 GHz and 6.6 GHz. The average insertion loss, ~ 2.5 dB, was measured to have a 20% bandwidth at 6 GHz. The planar phase shifter presented here demonstrates a compact design, low loss, and an especially large phase shift with a relatively small bias field.