Abstract: A communication device includes an antenna positioned within the communication device and configured to radiate a radiofrequency communication signal with a first frequency band and a conductive chassis containing the antenna within the communication device. A conductive wall portion of the conductive chassis forms a conductive exterior surface of the communication device. The antenna is positioned in proximity to the conductive wall portion to radiate the radiofrequency communication signal through the conductive wall portion. The conductive wall portion includes a pattern of apertures. At least one dimension of each aperture is less than or equal to a wavelength of a center frequency of the first frequency band.