Delay control via the bias field angle in YIG films

Theory which predicts the behavior of magnetostatic volume wave propagation in YIG films with the magnetic bias field applied at an arbitrary angle was developed. Measurements performed with the bias field applied in the plane defined by the film normal and the direction of propagation yielded results which were in good agreement with the theory. A variable delay line obtained by varying the direction of the bias field applied to an approximately constant forward volume wave delay line was demonstrated. The time delay of this device was adjustable over a ± 20% delay range and had a bandwidth of ∼150 MHz at X-band.