Wireless measuring system and method for measurement of a device under test with an antenna-array, considering maximum gain direction of the antenna array
A measuring system for measuring a communications device comprising an antenna-array. The measuring system comprises a controller, a measuring device, a measuring antenna and a device mount. The measuring device performs measurements with regard to the communications device. The device mount rotates the communications device about at least one axis. The controller sets a maximum gain direction of the antenna-array. The controller (i) controls the device mount to rotate the communications device, compensating for the set maximum gain direction, until the set maximum gain direction meets a direction of the measuring antenna with respect to the communications device, and (ii) determines an actual maximum gain direction of the antenna-array by iteratively rotating the communications device and determining a respective gain for each iteration, and determines the actual maximum gain direction as a rotation of the device mount that corresponds to the iteration of maximal gain.
1. A measuring system comprising:
a measuring device configured to perform measurements with regard to a communications device that employs an antenna-array;
at least one measuring antenna;
a device mount configured to hold the communications device and to rotate the communications device about at least one axis; and
a controller configured to set an antenna characteristic of the antenna-array of the communications device, whereby the controller is configured to control the device mount to rotate the communications device, compensating for a set maximum gain direction of the antenna-array, until the set maximum gain direction of the antenna-array meets a direction of the measuring antenna with respect to the communications device, and to thereby adjust the set maximum gain direction of the antenna-array.
2. The measuring system according to claim 1 , wherein the controller is configured to determine an actual maximum gain direction of the antenna-array by iteratively controlling the device mount to rotate the communications device and determining a respective gain of the antenna-array for each iteration, and determining the actual maximum gain direction of the antenna-array as a rotation of the device mount that corresponds to the iteration of maximum gain.
3. The measuring system according to claim 2 , wherein the controller is further configured to determine a maximum gain misalignment by determining a difference between the set maximum gain direction of the antenna-array and the actual maximum gain direction of the antenna-array.
4. The measuring system according to claim 2 , wherein the controller is configured to determine the actual maximum gain direction of the antenna-array by:
determining a gain difference between the respective gain for a current iteration and the respective gain for a previous iteration;
when the gain difference is negative and above a first pre-specified threshold, reversing a direction of rotation of the communications device for a subsequent iteration, or when the gain difference is positive and below a second pre-specified threshold, reducing a rotation amount for the subsequent iteration; and
continuing the iterations and determining the actual maximum gain direction of the antenna-array as the gain direction of the iteration where the gain difference is below the first pre-specified threshold.
5. The measuring system according to claim 2 , wherein, for a reception measurement, the measuring device is a signal generator configured to generate a measuring signal, and the measuring antenna is configured to transmit the measuring signal generated by the signal generator to the communications device.
6. The measuring system according to claim 5 , wherein the controller is configured to determine the respective gain of the antenna-array for each iteration by controlling the communications device to measure a reception power of the measuring signal, and comparing the reception power to a transmission power of the measuring signal.
7. The measuring system according to claim 2 , wherein, for a transmission measurement, the measuring device is a signal analyzer, and the controller is configured to control the communications device to generate a measuring signal and to transmit the measuring signal to the measuring antenna, and the signal analyzer is configured to receive the measuring signal.
8. The measuring system according to claim 7 , wherein the controller is configured to determine the respective gain of the antenna-array for each iteration by controlling the signal analyzer to measure a reception power of the measuring signal, and comparing the reception power to a transmission power of the measuring signal.
9. The measuring system according to claim 1 , wherein the device mount is configured to rotate the communications device about more than one axis.
10. A measuring method comprising:
positioning a communications device employing an antenna-array in a device mount of a measuring system; and
setting an antenna characteristic of the antenna-array of the communications device by rotating the communications device via the device mount, compensating for a set maximum gain direction of the antenna-array, until the set maximum gain direction of the antenna-array meets a direction of the measuring antenna with respect to the communications device, and thereby adjusting the set maximum gain direction of the antenna-array.
11. The measuring method according to claim 10 , further comprising:
determining an actual maximum gain direction of the antenna-array by iteratively rotating the communications device via the device mount and determining a respective gain of the antenna-array for each iteration, and determining the actual maximum gain of the antenna-array as a rotation of the device mount that corresponds to the iteration of maximum gain.
12. The measuring method according to claim 11 , wherein the method further comprises:
determining a maximum gain misalignment by determining a difference between the set maximum gain direction of the antenna-array and the actual maximum gain direction of the antenna-array.
13. The measuring method according to claim 11 , wherein the determination of the actual maximum gain direction of the antenna-array comprises:
determining a gain difference between the respective gain for a current iteration and the respective gain for a previous iteration;
when the gain difference is negative and above a first pre-specified threshold, reversing a direction of rotation of the communications device for a subsequent iteration, or when the gain difference is positive and below a second pre-specified threshold, reducing a rotation amount for the subsequent iteration; and
continuing the iterations and determining the actual maximum gain direction of the antenna-array as the gain direction of the iteration where the gain difference is below the first pre-specified threshold.
14. The measuring method according to claim 11 , wherein for a reception measurement, the method comprises:
generating a measuring signal; and
transmitting the measuring signal to the communications device.
15. Measuring method according to claim 14 , wherein the determination of the respective gain of the antenna-array for each iteration comprises:
measuring a reception power of the measuring signal; and
comparing the reception power to a transmission power of the measuring signal.
16. The measuring method according to claim 11 , wherein for a transmission measurement, the method comprises:
controlling the communications device to generate a measuring signal and to transmit the measuring signal to the measuring system; and
receiving the measuring signal via a measuring antenna of the measuring system.
17. The measuring method according to claim 16 , wherein the determination of the respective gain of the antenna-array for each iteration comprises:
measuring a reception power of the measuring signal; and
comparing the reception power to a transmission power of the measuring signal.