Thin-film magneto-inductive cables

A magneto-inductive wave wireless power transfer device

“…The coupling can however be much larger if structures use more than one later and the cells of each layer are overlapped [20]. Alternately quasi-axial structures using cells each of which overlays the next by half its width also give good performance with coupling reported at k ¼ 0.675 [21] although these have only been demonstrated using cells with very high aspect ratios (very long in the line direction). Using one or more of these approaches it is thus possible to significantly improve on the performance of our test structure.…”

“…Using the circuit modeling method we have investigated how much efficiency could be improved as the kQ value increases. Literature values for magneto-inductive cables for instance [21], give Q of 48 and k ¼ 0.675 to a total of 32. To explore the potential we calculate the power transfer to our single turn terminal for a variety of cell resistances and kQ values and the results are shown in Fig.…”

Noise performance of magneto-inductive cables

“…These factors inescapably makes the MI cable more lossy than continuous alternatives, and cannot be reduced: we require large inter-loop coupling for effective propagation, and this requires large loop overlap, as has been shown previously [20]. To improve the MI cable performance, the track resistance must be reduced.…”

“…An alternative approach is to form the loops on a flexible substrate as the elements of a cable [20]. Using double-sided patterning, the loops can be overlaid to enhance their coupling, and thus form cables that have low loss and are insensitive to bending [21].…”

“…If this occurs, rapid heating ensues. MI waveguide cables, on the other hand, have no continuous electrical paths, and so are inherently MRI-safe [20,22]. They can be wrapped around a catheter and are compatible with procedures such as endoscopic insertion [22,23].…”