The magnetic force between the electromagnet and plunger of a magnetic actuator, the electromagnet including a coil generating magnetic flux when the coil is energized, can be increased by locating a near field plate on the electromagnet. The near field plate has a spatially modulated surface reactance configured to focus the magnetic flux within a region of the plunger, such as the central portion of an end portion of the plunger proximate the electromagnet, so as to increase the magnetic force between the electromagnet and plunger. Examples also include permanent magnet based actuators and the use of other magnetic field focusing devices.