SYSTEM FOR TESTING MULTI-ANTENNA DEVICES

• US 20110084887A1
• Filed: 10/09/2009
• Published: 04/14/2011
• Est. Priority Date: 10/09/2009
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Mow, Matt A., Schlub, Robert W., Caballero, Ruben
• Granted Patent: US 9,002,287 B2
• Time in Patent Office: Days
• US Class Current: 343/703
• CPC Class Codes: G01R 29/10 Radiation diagrams of antennas

Abstract

A test system for testing multiple-input and multiple-output (MIMO) systems is provided. The test system may convey signals bidirectionally between two test chambers. Each test chamber may be lined with foam to minimize electromagnetic reflections. Each test chamber may include structure three-dimensional array of test antennas. The test antennas may be mounted in a sphere using an antenna mounting structure. The antenna mounting structure may include multiple rings of different sizes. Test antennas may be embedded in the inner walls of the antenna mounting structure. There may be multiple receiving antennas located in each test chamber. One test chamber may include a device under test inside an array of test antennas and another test chamber may include base station antennas inside another array of test antennas. Signals may be conveyed between the test chambers using channel emulators.

Claims

1. A wireless test system, comprising:

a test chamber;

a three-dimensional array of test antennas within the test chamber; and

radio-frequency circuitry coupled to the array of test antennas.

2. The wireless test system defined in claim 1 wherein the radio-frequency circuitry includes at least one channel emulator having a plurality of ports each of which is coupled to a respective one of the test antennas.

3. The wireless test system defined in claim 2 further comprising a plurality of planar two-dimensional antenna mounting structures on which the test antennas are mounted.

4. The wireless test system defined in claim 3 further comprising positioning equipment that moves the planar two-dimensional antenna mounting structures.

5. The wireless test system defined in claim 4 further comprising hollow members that couple the planar two-dimensional antenna mounting structures to the positioning equipment.

6. The wireless test system defined in claim 1 wherein the test system comprises a fixed device-under-test mounting structure positioned at least partly within the three-dimensional array of test antennas.

7. The wireless test system defined in claim 1 further comprising positioning equipment that moves the array of test antennas within the test chamber.

8. The wireless test system defined in claim 7 wherein the array of test antennas includes at least 20 antennas.

9. The wireless test system defined in claim 1 further comprising:

a channel emulator;

at least one path that couples the channel emulator to each of the test antennas in the three-dimensional array of test antennas; and

a plurality of receiving antennas located within the test chamber and outside of the three-dimensional array of test antennas.

10. The wireless test system defined in claim 1 wherein the array of test antennas includes at least 20 test antennas.

11. The wireless test system defined in claim 10 further comprising a plurality of controllable tuners that adjust antenna port impedances during test measurements.

12. The wireless test system defined in claim 1 wherein the test antennas comprise horn antennas.

13. The wireless test system defined in claim 1 wherein the radio-frequency circuitry is configured to adjust radio-frequency signal amplitudes for radio-frequency signals transmitted through the test antennas.

14. The wireless test system defined in claim 1 wherein the radio-frequency circuitry is configured to adjust radio-frequency signal phases for radio-frequency signals transmitted through the test antennas.

15. The wireless test system defined in claim 1 further comprising:

a channel emulator having an input; and

at least one path that conveys signals to the input of the channel emulator from the test antennas in the three-dimensional array of test antennas.

16. A test system, comprising:

a first test chamber having a first plurality of test antennas arranged in a three-dimensional array and having at least a first receiving antenna; and

a second test chamber having a second plurality of test antennas arranged in a three-dimensional array 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.

17. The test system defined in claim 16 further comprising:

a first channel emulator that conveys signals from the first receiving antenna to the second plurality of test antennas.

18. The test system defined in claim 17 further comprising a second channel emulator that conveys signals from the second receiving antenna to the first plurality of test antennas.

19. The test system defined in claim 18 wherein the first test chamber comprises a spherical antenna mounting structure on which the first plurality of test antennas are mounted.

20. The test system defined in claim 19 wherein the second test chamber comprises a spherical antenna mounting structure on which the second plurality of test antennas are mounted.

21. 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; and

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.

22. The method defined in claim 21 further comprising:

with the second plurality of receiving antennas, receiving radio-frequency signals from each of the plurality of device antennas in the second test chamber;

with the second channel emulator, conveying the received radio-frequency signals from the second plurality of receiving antennas to the first plurality of test antennas; and

with the first plurality of test antennas, transmitting radio-frequency signals from the second channel emulator to each of the plurality of wireless equipment antennas.

23. The method defined in claim 22 wherein the wireless equipment antennas comprise base station antennas and wherein the device antennas comprises handheld electronic device antennas, wherein transmitting the radio-frequency signals from the first channel emulator to each of the antennas of the multi-antenna device under test comprises transmitting radio-frequency signals to the handheld electronic device antennas, and wherein transmitting radio-frequency signals from the second channel emulator to each of the plurality of wireless equipment antennas comprises transmitting radio-frequency signals to the base station antennas.