On the latching of ferrite microwave devices

An empirical formula is derived for the hysteresis (B-H) loop of a ferrite material along with an analysis of the latching properties of a ferrite phase shifter. It is shown possible to model the major magnetostatic B-H loop of toroidal samples of some microwave ferrite materials by using the measured parameters of the material. A formula is presented for approximate minor loops and switching trajectories typical of latching reciprocal phase shifters. A relationship between amplitude, pulse width, and number of pulses needed to switch a toroid was found in terms of the number of turns on the toroid, the switching current, and the latching remanent flux, and is in agreement with experimental results.