Magnetic fields study of various planar Halbach permanent magnet array

The magnetic fields due to different planar Halbach permanent magnet (PM) array, including the 4 piece square array, stretched 8 piece square array and trapezoid array, are studied by analytic calculation method and FEM. On this basis, the magnetic forces over the magnet weight per array unit area are obtained. Then comparisons of above results indicate that the trapezoid array can provide the maximum field amplitude, the more pure sinusoidal field and maximum force, thus help us optimally use of the various Halbach array.