Device and method for calibrating antenna array systems
A method and a system for calibrating an antenna array. The method may include the following steps: attaching successively pairs of a plurality of probe antennas to each other; performing an initial measurement of a multiport formed by the ports of said pair of probe antennas, the initial measurement yielding initial coefficients of said probe antennas; attaching successively one of said probe antennas to one of the antennas in said antenna array; performing a second measurement of multiports formed by the ports of said probe antennas and said antenna array, the second measurement yielding coefficients of the combination of said antenna array and said probe antennas; and using the initial coefficients and the second measurement coefficients to calibrate said antenna array.
1. A method for calibrating an antenna array using probe antennas, said antenna array comprising a plurality of antennas and said probe antennas comprising a plurality of probe antennas, the method comprising:
(a) representing the response of an antenna of said antenna array or said probe antennas by network parameters of a 2-port device wherein one port of said 2-port device is a physical antenna port, and the other port is a spatial antenna port;
(b) representing the response from one antenna attached to another antenna for an antenna pair as a concatenation of the response from the physical port to the spatial port of a first antenna and the response from the spatial port to the physical port of a second antenna;
(c) attaching successively a first antenna of the plurality of probe antennas to a second antenna of said plurality of probe antennas for a plurality of pairs of said plurality of probe antennas;
(d) measuring for each probe antenna pair of said plurality of pairs, the S-parameters between the physical ports of said plurality of probe antennas;
(e) extracting from said measurements the network parameters of the plurality of probe antennas;
(f) attaching successively the plurality of antennas of the antenna array to at least one antenna of said plurality of probe antennas for a plurality of antenna pairs;
(g) measuring for each said plurality of antenna pairs the S-parameters between the physical ports of said pairs of antennas; and
(h) extracting the network parameters of each antenna in the antenna array using said S-parameters measurements and the extracted network parameters of said plurality of probe antennas.
2. A method of claim 1 , wherein said network parameters are one of S-parameters, T-parameters, Z-parameters or Y-parameters.
3. The method according to claim 1 , wherein said S-parameters measurements are performed by a Radio Frequency Signals Measurement Unit (RFSMU).
4. The method according to claim 3 , wherein said RFSMU is a Vector Network Analyzer (VNA).
5. The method according to claim 1 wherein said plurality of probe antennas comprises three antennas.