A new magnetostatic wave delay line using YIG film

We have proposed a delay line of microstrip type consisting of a microstrip line fabricated on a composite substrate of two yttrium iron garnet films separated by a gadolinium gallium garnet layer. The dispersion relations are derived assuming magnetic walls at the edges of the strip. Experiments are carried out at S band with nonuniform magnetic field. Insertion loss less than 25 dB with large delay time more than 800 ns is observed experimentally. The experimental results on delay line characteristics are briefly discussed with theory.