Slowly dispersive, short time delay line based on very thick liquid phase epitaxially grown yttrium iron garnet

Preliminary results on a magnetostatic volume wave delay line based on very thick yttrium iron garnet films (=110 μm) and operating in the 2–12 GHz frequency range, are presented. As expected from the theoretical dependence on the film-thickness, dispersion characteristics appear to be particularly interesting whenever short and slowly varying (slope of 0.05 ns/MHz) delay times are needed. Typically, for forward modes in the 9.5-10.5 interval, the average insertion loss is 12 dB with a −3 dB bandwidth of 550 MHz (reaching almost 900 MHz in the −10 dB limit). The precautions taken to eliminate (within a ±1.5 dB tolerance) band ripples, and relative consequences on the bandwidth and delay time linearity, are also discussed.