System for testing multi-antenna devices

A test system, comprising:

• a first test chamber having a first plurality of transmitting test antennas surrounding a device under test and having at least a first receiving antenna, wherein the first plurality of transmitting test antenna are configured to transmit radio-frequency test signals to the device under test, wherein the at least first receiving antenna is configured to receive corresponding radio-frequency test signals from the device under test, the first plurality of transmitting test antennas are positioned at first distances from the device under test, the first receiving antenna is positioned at a second distance from the device under test that is greater than the first distances, the first test chamber comprises a plurality of retractable ring-shaped antenna mounting structures on which the first plurality of transmitting test antennas are mounted, the plurality of retractable ring-shaped antenna mounting structures share a common concentric axis, and the plurality of retractable ring-shaped antenna mounting structures have different sizes that form a spherical antenna mounting structure;
• and
• a second test chamber having a second plurality of transmitting test antennas and having at least a second receiving antenna, wherein signals received by the first receiving antenna are conveyed to the second test chamber and wherein signals received by the second receiving antenna are conveyed to the first test chamber.

A method of testing a multi-antenna device under test that has a plurality of device antennas and multi-antenna wireless equipment that has a plurality of wireless equipment antennas using a test system that has first and second channel emulators and first and second test chambers, wherein the first and second test chambers include respective first and second pluralities of test antennas arranged in respective three-dimensional arrays and include respective first and second pluralities of receiving antennas, comprising:

• with the first plurality of receiving antennas, receiving radio-frequency signals from each of the plurality of wireless equipment antennas in the first test chamber;
• with the first channel emulator, conveying the received radio-frequency signals from the first plurality of receiving antennas to the second plurality of test antennas;
• with the second plurality of test antennas, transmitting radio-frequency signals from the first channel emulator to each of the antennas of the multi-antenna device under test, wherein the second plurality of test antenna are mounted on a plurality of retractable ring-shaped antenna mounting structures that share a common concentric axis and have different sizes that form a spherical antenna mounting structure;
• and
• with positioning structures, adjusting a position for at least some of the retractable ring-shaped antenna mounting structures with respect to one another.