SYSTEM AND METHOD FOR CALIBRATION AND MONITORING OF AN ANECHOIC BOUNDARY ARRAY RF ENVIRONMENT SIMULATOR

• US 20160344490A1
• Filed: 12/08/2015
• Published: 11/24/2016
• Est. Priority Date: 05/19/2015
• Status: Active Grant

• Current Assignee: Ets-Lindgren Incorporated (ESCO Technologies, Inc.)
• Original Assignee: Ets-Lindgren Incorporated (ESCO Technologies, Inc.)
• Inventors: FOEGELLE, Michael David
• Granted Patent: US 9,979,496 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 17/11 for calibration
• CPC Class Codes: H04B 17/3912 Simulation models, e.g. distribution of spectral power density or received signal strength indicator [RSSI] for a given geographic region

Abstract

Some embodiments include a system for simulating electromagnetic environments that includes a channel emulator having a plurality of outputs, each output associated with a different operational path. Each operational path has a power amplifier, an antenna and a first coupling mechanism. The power amplifier is coupled to an output of the channel emulator. The antenna is in communication with a test region of the apparatus. The first coupling mechanism simultaneously couples power to the antenna and to a first measurement path when the operational path is coupled to the test region, so that a calibration state of the operational path can be determined and adjusted without interruption of a signal coupled to the antenna in the operational path.

Claims

1. A system for simulating electromagnetic environments configured to determine a calibration state of each of at least one operational path, each of the at least one operational path having an antenna in communication with a test region, the calibration state of an operational path being determined without interruption of a portion of a power amplifier output signal coupled to the antenna, the apparatus comprising:

a channel emulator having an output for each operational path;

each operational path including;

at least a power amplifier having an input coupled to an output path of the channel emulator, the power amplifier having an output signal;

an antenna in communication with the test region and configured to receive a first portion of the power amplifier output signal; and

a first coupling apparatus having an input receiving an output signal of the power amplifier and at least two outputs and being configured to simultaneously couple the first portion of the power amplifier output signal to the antenna and a second portion of the power amplifier output signal to a first monitoring path when the operational path is being used to test a device in the test region, so that a calibration state of at least a portion of the operational path can be determined without interruption of the first portion of the power amplifier output signal coupled to the antenna.

2. The system of claim 1, further comprising a first measurement device in the first monitoring path and configured to measure the second portion of the power amplifier output signal.

3. The system of claim 2, wherein the first measurement device is combined with the first coupling apparatus and the power amplifier in a package install-able between the channel emulator and the antenna.

4. The system of claim 1, further comprising a second coupling apparatus having an input coupled to an output of the channel emulator, having a first output coupled to an input of the power amplifier, and having a second output coupled to a second monitoring path.

5. The system of claim 4, further comprising a controller coupled to the first and second monitoring paths and configured to compare an output of the first coupling apparatus to an output of the second coupling apparatus to produce a gain control signal to control a gain of the power amplifier.

6. The system of claim 5, wherein the gain control signal is based at least in part on a stored calibration value.

7. The system of claim 6, wherein the gain control signal is set by the controller so that the output of the first coupling apparatus coupled to the first monitoring path is about equal to the stored calibration value.

8. A method for monitoring calibration of a system for simulating electromagnetic environments having a plurality of antennas in communication with a test region, each antenna in a different operational path of the apparatus, each operational path having a power amplifier, a coupling device and an antenna, the coupling device configured to simultaneously couple power to the antenna and to a first monitoring path so that signal flow through the operational path is not interrupted when a signal in the first monitoring path is coupled to a power sensor, the method comprising:

measuring power coupled to the first monitoring path while signal flow through the operational path is not interrupted; and

comparing the measured power to an expected value.

9. The method of claim 8, further comprising adjusting a gain of the power amplifier in the operational path based on a result of the comparison.

10. The method of claim 8, further comprising adjusting the channel emulator based on a result of the comparison.

11. The method of claim 8, wherein the predetermined calibration value is based on a path loss measurement of an operational path that includes providing a reference antenna in communication with the test region, the reference antenna configured to receive power radiated into the test region by the antenna in the operational path.

12. The method of claim 11, wherein determining the path loss includes providing test equipment having a receive port coupled to the reference antenna and a transmit port coupled to an input of the operational path.

13. The method of claim 12, wherein the test equipment is a network analyzer.

14. The method of claim 8, further comprising determining an input calibration power level of the power amplifier in the operational path.

15. A system for simulating electromagnetic environments, comprising:

a channel emulator having a plurality of outputs, each output associated with a different operational path, each operational path having;

a power amplifier coupled to an output of the channel emulator;

an antenna in communication with test region of the apparatus; and

a first coupling mechanism to simultaneously couple power to the antenna and to a first monitoring path when the operational path is coupled to the test region, so that a calibration state of at least a portion of the operational path can be determined without interruption of a signal coupled to the antenna in the operational path.

16. The system of claim 15, further comprising a measurement device coupled to the first monitoring path, the measurement device providing a measurement of an output of the power amplifier in the operational path.

17. The system of claim 16, further comprising a comparator configured to compare the measurement to a calibration value.

18. The system of claim 17, further comprising a gain control device configured to adjust the gain of the power amplifier based on the comparison.

19. The system of claim 18, wherein the gain of the power amplifier is set so that the measure of the output of the power amplifier is about equal to the calibration value.

20. The system of claim 15, further comprising a gain control device configured to adjust a gain of the channel emulator based on a result of the comparison.

21. The system of claim 15, further comprising a second coupling mechanism to couple an output of the channel emulator to a second monitoring path.

22. The system of claim 21, wherein a signal on the second monitoring path is compared to a signal on the first monitoring path to determine an adjustment to a gain of the power amplifier.

23. A system for simulating an electromagnetic environments, the system configured to determine a calibration state of at least one operational path, the calibration state of an operational path being determined without interruption of a portion of a signal from an antenna to an amplifier in the operational path, the apparatus comprising:

a channel emulator having an input for each operational path;

each operational path including;

an antenna in communication with the test region and configured to receive signals transmitted from a device under test in the test region;

an amplifier having an output coupled to an input of the channel emulator and having an input to receive a first portion of the transmitted signals from the antenna;

a first coupling apparatus having an input receiving the transmitted signals from the antenna, and having at least two outputs and being configured to simultaneously couple the first portion of the transmitted signals to the amplifier and to couple a second portion of the transmitted signals to a first monitoring path when the operational path is being used to test a device in the test region, so that a calibration state of at least a portion of the operational path can be determined without interruption of the first portion of the transmitted signals coupled to the amplifier.

24. The system of claim 23, further comprising a first measurement device in the first monitoring path and configured to measure the second portion of the transmitted signals.

25. The system of claim 24, wherein the first measurement device is combined with the first coupling apparatus and the power amplifier in a package install-able between the channel emulator and the antenna.

26. A method for monitoring calibration of a system for simulating electromagnetic environments having a plurality of antennas in communication with a test region, each antenna in a different operational path of the apparatus, each operational path having an amplifier, a coupling device and an antenna, the coupling device configured to simultaneously couple power from the antenna to a first monitoring path so that a signal flow through the operational path is not interrupted when a signal in the first monitoring path is coupled to a power sensor, the method comprising:

measuring power coupled to the first monitoring path while signal flow through the operational path is not interrupted; and

comparing the measured power to an expected value.