Transfer switches for high performance contiguous-disk magnetic bubble devices

New transfer switches for 4-μm period ion-implanted contiguous-disk bubble devices are reported. Bubbles are translated through the major loop during WRITE-line transfer so that the data appear at the detector-after transfer from the storage loops-in the same order as they are written into the chip. Bias field margins of ∼8 percent have been obtained at drive field frequencies in the range of 100-400 kHz, making the designs particularly suitable for high performance (that is, short access time, high data rate) applications. Long-term testing has shown that such components can be operated over many cycles with only a modest degradation in bias margin of 0.5 Oe per decade.