The object of this program has been to evaluate the utility of ferrite microstrip devices which use externally applied magnetic fields as opposed to latched remnant fields. Although the latched devices call for less average magnetic field current, devices with externally applied fields show promise of greater figure of merit. Since Reggia-Spencer devices can achieve figures of merit in excess of 1000/spl deg/ / dB, it was decided to investigate the potentialities of externally magnetized devices in an attempt to increase figure of merit and bandwidth, and to reduce size and weight compared to the Reggia-Spencer device.