ARRAY FOR WIRED TESTING OF MULTI-INPUT AND MULTI-OUTPUT SIGNALS

1 . An electronic device, comprising:

N input connectors;

M output connectors, wherein N and M are non-zero integers and M is greater than N; and

phase-shift elements configured to provide predefined phases between the N input connectors and the M output connectors, wherein the electronic device is configured to provide a modified Butler matrix in which:

N input electrical signals provided to the N input connectors result in N output electrical signals corresponding to the N input electrical signals on N of the M output connectors, wherein the N output electrical signals are orthogonal to each other; and

the N input electrical signals result in P output electrical signals corresponding to the N input electrical signals on P of the M output connectors, wherein the P output electrical signals are orthogonal to each other, but are not orthogonal to the N output electrical signals, wherein P is a non-zero integer, wherein the P output electrical signals are linear combinations of the N input electrical signals in which the N input electrical signals have corresponding second phases, and wherein a dot product of a given one of the N output electrical signals with a given one of the P output electrical signals equals a non-zero predefined value.

2 . The electronic device of claim 1 , wherein N is 4 and M is 8.

3 . The electronic device of claim 1 , wherein N is 4 and M is 16.

4 . The electronic device of claim 1 , wherein the N input electrical signals are radio-frequency electrical signals.

5 . The electronic device of claim 1 , wherein a given input connector or a given output connector is a SubMinature version A (SMA) connector or another type of coaxial connector.

6 . The electronic device of claim 1 , wherein the N output electrical signals in the linear combinations have equal amplitudes.

7 . The electronic device of claim 1 , wherein the M output electrical signals have maximal phase separation from each other in an M×M space.

8 . The electronic device of claim 1 , wherein the electronic device is configured to provide the modified Butler matrix in which:

the N input electrical signals result in Q output electrical signals corresponding to the N input electrical signals on a Q of the M output connectors, wherein the Q output electrical signals are orthogonal to each other, but are not orthogonal to the N output electrical signals, and wherein Q is a non-zero integer; and

the Q output electrical signals are second linear combinations of the N input electrical signals in which the N input electrical signals have corresponding third phases, wherein a dot product of a given one of the N output electrical signals with a given one of the Q output electrical signals equals a second non-zero predefined value in a set of second non-zero predefined values, and wherein the give second non-zero predefined value is different from the predefined value.

9 . The electronic device of claim 8 , wherein the N output electrical signals in the second linear combinations have equal amplitudes.

10 . The electronic device of claim 8 , wherein the M output electrical signals have maximal phase separation from each other in an M×M space.

11 . A method for performing testing, comprising:

by an electronic device:

receiving, at N input connectors, N input electrical signals; and

providing, at M output connectors, M output electrical signals, wherein the M output electrical signals comprise:

N output electrical signals corresponding to the N input electrical signals on N of the M output connectors, wherein the N output electrical signals are orthogonal to each other; and

P output electrical signals corresponding to the N input electrical signals on P of the M output connectors, wherein the P output electrical signals are orthogonal to each other, but are not orthogonal to the N output electrical signals, wherein P is a non-zero integer, wherein the P output electrical signals are linear combinations of the N input electrical signals in which the N input electrical signals have corresponding second phases, and wherein a dot product of a given one of the N output electrical signals with a given one of the P output electrical signals equals a non-zero predefined value.

12 . The method of claim 11 , wherein N is 4 and M is 8.

13 . The method of claim 11 , wherein N is 4 and M is 16.

14 . The method of claim 11 , wherein the N input electrical signals are radio-frequency electrical signals.

15 . The method of claim 11 , wherein a given input connector or a given output connector is a SubMinature version A (SMA) connector or another type of coaxial connector.

16 . The method of claim 11 , wherein the N output electrical signals in the linear combinations have equal amplitudes.

17 . The method of claim 11 , wherein the M output electrical signals have maximal phase separation from each other in an M×M space.

18 . The method of claim 11 , wherein the M output electrical signals comprise:

Q output electrical signals corresponding to the N input electrical signals on a Q of the M output connectors, wherein the Q output electrical signals are orthogonal to each other, but are not orthogonal to the N output electrical signals, wherein Q is a non-zero integer, wherein the Q output electrical signals are second linear combinations of the N input electrical signals in which the N input electrical signals have corresponding third phases, wherein a dot product of a given one of the N output electrical signals with a given one of the Q output electrical signals equals a second non-zero predefined value in a set of second non-zero predefined values, and wherein the give second non-zero predefined value is different from the predefined value.

19 . The method of claim 18 , wherein the N output electrical signals in the second linear combinations have equal amplitudes.

20 . The method of claim 18 , wherein the M output electrical signals have maximal phase separation from each other in an M×M space.