A power transmitter for wireless power transfer at an operating frequency selected from a range of about 87 kilohertz (kHz) to about 360 kHz is disclosed. The power transmitter includes a control and communications unit and an inverter circuit configured to receive input power and convert the input power to a power signal. The power transmitter further includes a coil configured to transmit the power signal to a power receiver, the coil formed of wound Litz wire and including at least one layer. The power transmitter further includes a shielding comprising a magnetic backing and a magnetic wall, the magnetic wall and magnetic backing defining a cavity, the magnetic wall including a top surface, the cavity extending, at least, from the magnetic backing to the coil, the coil positioned proximate to the top surface.