Switching criteria for waveguide ferrite devices

A microwave ferrite device becomes a switch when actuated by a pulsed magnetic field. Because of the changing magnetic field, eddy currents are induced in the waveguide walls which results in a certain degree of shielding. In this paper, a criterion is given for the shielding effect of the waveguide walls to sinusoids to meet the switching response in the time domain when the field is applied through a long solenoid. It is also shown that the criterion can be obtained from inductance measurements. In this way the switching response can be specified in terms of the frequency response, thereby greatly facilitating design.