System and method for testing radio frequency wireless signal transceivers using wireless test signals
View Patent ↗A system and method for facilitating wireless testing of a radio frequency (RF) signal transceiver device under test (DUT). Using multiple antennas within a shielded enclosure containing the DUT, multiple wireless RF test signals resulting from a RF test signal radiated from the DUT can be captured and have their respective signal phases controlled in accordance with one or more signal characteristics, including their respective signal power levels, their respective signal phases as received, and a signal power level of a combination of the received signals. Such phase control of the captured wireless RF test signals can be performed individually for any DUT tested within the shielded enclosure, thereby providing compensation for the multipath signal environment within the shielded enclosure irrespective of the placement of the DUT, and thereby simulating a wired test signal path during wireless testing of the DUT.
1. An apparatus including a system to facilitate wireless testing of a radio frequency (RF) signal transceiver device under test (DUT), comprising:
a structure defining interior and exterior regions and configured to allow placement of a DUT within said interior region and to be substantially isolated from electromagnetic radiation originating from said exterior region;
a plurality of antennas disposed at least partially within said interior region to receive at least one plurality of wireless RF test signals related to a common RF test signal radiated from said DUT, and to transmit another plurality of wireless RF test signals to said DUT, wherein said received and transmitted RF test signals are received and transmitted via common ones of said plurality of antennas; and
RF signal control circuitry coupled to said plurality of antennas and responsive to said at least one plurality of wireless RF test signals by
controlling, in accordance with one or more phase control signals, respective phases of at least a portion of said at least one plurality of wireless RF test signals to provide at least one plurality of phase-controlled RF test signals,
measuring and combining said at least one plurality of phase-controlled RF test signals to provide said one or more phase control signals and a RF output signal related to a combination of said at least one plurality of phase-controlled RF test signals, and
repeating said controlling and said measuring and combining until a maximized signal power is attained for at least one of
a cumulative power of said at least one plurality of phase-controlled RF test signals, and
said RF output signal;
wherein said RF signal control circuitry provides said RF output signal via a conductive signal path for direct reception therefrom by a tester, and said interior region contains the only over-the-air (OTA) signal environment between said DUT and said tester.
2. The apparatus of claim 1 , wherein said RF signal control circuitry comprises:
phase control circuitry coupled to said plurality of antennas and responsive to said at least one plurality of wireless RF test signals and said one or more phase control signals by providing said at least one plurality of phase-controlled RF test signals;
control signal circuitry coupled to said phase control circuitry and responsive to said at least one plurality of phase-controlled RF test signals by providing said one or more phase control signals; and
combining circuitry coupled to at least one of said phase control circuitry and said control signal circuitry, and responsive to said at least one plurality of phase-controlled RF test signals by providing said RF output signal.
3. The apparatus of claim 2 , wherein said control signal circuitry comprises power detection circuitry.
4. The apparatus of claim 2 , wherein said control signal circuitry comprises:
power measurement circuitry responsive to said at least one plurality of phase-controlled RF test signals by providing a plurality of power signals indicative of respective power levels of each of said at least one plurality of phase-controlled RF test signals; and
processing circuitry coupled to said power measurement circuitry and responsive to said plurality of power signals by providing said one or more phase control signals.
5. The apparatus of claim 2 , wherein said control signal circuitry comprises phase detection circuitry.
6. The apparatus of claim 2 , wherein said control signal circuitry comprises:
phase measurement circuitry responsive to said at least one plurality of phase-controlled RF test signals by providing a plurality of phase signals indicative of respective signal phases of each of said at least one plurality of phase-controlled RF test signals; and
processing circuitry coupled to said phase measurement circuitry and responsive to said plurality of phase signals by providing said one or more phase control signals.
7. The apparatus of claim 1 , wherein said RF signal control circuitry comprises:
phase control circuitry coupled to said plurality of antennas and responsive to said at least one plurality of wireless RF test signals and said one or more phase control signals by providing said at least one plurality of phase-controlled RF test signals;
combining circuitry coupled to said phase control circuitry and responsive to said at least one plurality of phase-controlled RF test signals by providing said RF output signal; and
control signal circuitry coupled to said combining circuitry and said phase control circuitry, and responsive to said RF output signal by providing said one or more phase control signals.
8. The apparatus of claim 7 , wherein said control signal circuitry comprises power detection circuitry.
9. The apparatus of claim 7 , wherein said control signal circuitry comprises:
power measurement circuitry responsive to said RF output signal by providing a power signal indicative of a power level of said RF output signal; and
processing circuitry coupled to said power measurement circuitry and responsive to said power signal by providing said one or more phase control signals.
10. A method of facilitating wireless testing of a radio frequency (RF) signal transceiver device under test (DUT), comprising:
providing a structure defining interior and exterior regions and configured to allow placement of a DUT within said interior region and to be substantially isolated from electromagnetic radiation originating from said exterior region;
providing a plurality of antennas disposed at least partially within said interior region to receive at least one plurality of wireless RF test signals related to a common RF test signal radiated from said DUT, and to transmit another plurality of wireless RF test signals to said DUT, wherein said received and transmitted RF test signals are received and transmitted via common ones of said plurality of antennas; and
responding to said at least one plurality of wireless RF test signals by
controlling, in accordance with one or more phase control signals, respective phases of at least a portion of said at least one plurality of wireless RF test signals to provide at least one plurality of phase-controlled RF test signals,
measuring and combining said at least one plurality of phase-controlled RF test signals to provide said one or more phase control signals and a RF output signal related to a combination of said at least one plurality of phase-controlled RF test signals, and
repeating said controlling and said measuring and combining until a maximized signal power is attained for at least one of
a cumulative power of said at least one plurality of phase-controlled RF test signals, and
said RF output signal;
wherein said RF output signal is provided via a conductive signal path for direct reception therefrom by a tester, and said interior region contains the only over-the-air (OTA) signal environment between said DUT and said tester.
11. The apparatus of claim 10 , wherein:
said controlling comprises responding to said at least one plurality of wireless RF test signals and said one or more phase control signals by providing said at least one plurality of phase-controlled RF test signals; and
said measuring and combining comprises
measuring said at least one plurality of phase-controlled RF test signals to provide said one or more phase control signals, and
combining said at least one plurality of phase-controlled RF test signals to provide said RF output signal.
12. The apparatus of claim 11 , wherein said measuring said at least one plurality of phase-controlled RF test signals comprises detecting at least one power of said at least one plurality of phase-controlled RF test signals.
13. The apparatus of claim 11 , wherein said measuring said at least one plurality of phase-controlled RF test signals comprises:
detecting at least one power of said at least one plurality of phase-controlled RF test signals to provide a plurality of power signals indicative of respective power levels of each of said at least one plurality of phase-controlled RF test signals; and
processing said plurality of power signals to provide said one or more phase control signals.
14. The apparatus of claim 11 , wherein said measuring said at least one plurality of phase-controlled RF test signals comprises detecting at least one phase of said at least one plurality of phase-controlled RF test signals.
15. The apparatus of claim 11 , wherein said measuring said at least one plurality of phase-controlled RF test signals comprises:
detecting at least one phase of said at least one plurality of phase-controlled RF test signals to provide a plurality of phase signals indicative of respective signal phases of each of said at least one plurality of phase-controlled RF test signals; and
processing said plurality of phase signals to provide said one or more phase control signals.
16. The apparatus of claim 10 , wherein:
said controlling comprises responding to said at least one plurality of wireless RF test signals and said one or more phase control signals by providing said at least one plurality of phase-controlled RF test signals; and
said measuring and combining comprises
combining said at least one plurality of phase-controlled RF test signals to provide said RF output signal, and
measuring said RF output signal to provide said one or more phase control signals.
17. The apparatus of claim 16 , wherein said measuring said RF output signal to provide said one or more phase control signals comprises detecting a power of said RF output signal.
18. The apparatus of claim 16 , wherein said measuring said RF output signal to provide said one or more phase control signals comprises:
detecting a power of said RF output signal to provide a power signal indicative of a power level of said RF output signal; and
processing said power signal to provide said one or more phase control signals.