A test system includes a radio frequency (RF) shielded chamber and an antenna array in the RF shielded chamber. The antenna array includes groups of antenna elements and power combiners. Each group of antenna elements is matched to a matching group of antenna elements by virtue of being coupled to a respective power combiner for both the group and the matching group. The antenna array is configured, by virtue of spacing apart the antenna elements by at least half of a wavelength of a test signal for testing a wireless device in the RF chamber, so that power delivered to output ports of the antenna array is substantially uniform regardless of where the wireless device is placed within the RF chamber.