Frequency Doubling in Ferrites

Abstract

The torque equation for the motion of the magnetization in a magnetized ferrite yields a component along the direction of the applied dc magnetic field. The time dependent part of this component is of second order in rf quantities and has previously been neglected. With high incident powers an observable double frequency output is predicted. A high intensity microwave magnetic field and an orthogonal dc magnetic field were applied to a ferrite body. Double frequency magnetic fields were generated in the same direction as the dc magnetizing field. A primary frequency of 3175 mc was used with peak powers up to 200 watts. The peak output power at 6350 mc was found to increase linearly with the square of the peak input power over a range of 42 db. Reasonable agreement was found between theory and experiment.