Different inductor configurations control the B Field to various degrees. If the winding coil is not completely surrounded by magnetic material, the B Field will leak into the air around the inductor and cause radiated EMI. The IHLP (composite inductor) does the best job of reducing B Field leakage flux since the magnetic material completely surrounds the coil with no discrete air gaps. Placing a ground plane in the PCB under the inductor can reduce the radiated EMI that extends below the PCB. Placing a ground shield on top of the inductor mitigates radiated EMI from the top of the inductor.