Tunable negative refractive index metamaterial phase shifter

A tunable compact phase shifter utilising negative refractive index metamaterial is demonstrated. The negative index metamaterial is composed of a periodic copper wire pattern sandwiched between two slabs of high quality yttrium iron garnet films. Near ferrimagnetic resonance, a phase shift tuning of 160°/kOe is achieved at 24 GHz. The insertion loss varies from 4 to 7 dB for a 1 cm-long composite.