An inductor arrangement, comprising: a first pair of driven inductors configured to be driven to generate magnetic fields which are substantially in antiphase, and arranged relative to one another so that their magnetic fields substantially cancel one another at a first null line between those inductors; and a second pair of driven inductors configured to produce magnetic fields which are substantially in antiphase, and arranged relative to one another so that their magnetic fields substantially cancel one another at a second null line between those inductors, wherein the pairs of driven inductors are arranged relative to one another so that the first and second null lines intersect one another, with the first pair of driven inductors located substantially on the second null line and the second pair of inductors located substantially on the first null line.