A case for a wireless tablet computer device includes a number of RF resonant loop elements and elongated RF director coupling strip elements mounted in the case and configured such that RF radiation is coupled from an internal antenna of the wireless device out of the device to the RF resonant and coupling elements. The case incorporates a cut-out section in a location leaving exposed a strip that covers an area proximate the internal antenna. The RF resonant loops and director coupling strip elements alternatively may be incorporated with the wireless tablet computer device itself.