M.S.W. nondispersive, electronically tunable time delay elements

A nondispersive, electronically tunable (165¿180 ns) time delay unit based on magnetostatic wave (m.s.w.) propagation with 6% bandwidth at 3 GHz has been demonstrated. The unit is implemented by cascading magnetostatic surface wave and magnetostatic backward volume wave delay lines designed so that the dispersion slopes are equal and opposite in slope over the common operating bandwidth; this produces an element with constant time delay over the bandwidth which can be adjusted by a bias field variation of one of the lines.