Antenna Characterisation in an Anechoic Chamber

With the advent of 5G, wireless communication systems are progressively incorporating massive MIMO antennas to support beamforming. To lower the time-to-market of these antenna systems it becomes important to characterise these antenna systems in a cost- and time-efficient manner. The most important figure of merit to accurately characterize is the antenna radiation pattern. While the amplitude component of the measured antenna radiation pattern does not pose as much of a problem, the phase component can be very sensitive to errors in the measurement setup. To obtain a correct phase profile, the spatial measurement sphere should be centred around the phase centre of the antenna under test. This is however practically impossible due to unavoidable manufacturing errors, the frequency dependency of the phase centre location, and the fact that the phase centre does not correspond to a physical point. At high frequencies even the smallest misalignment can lead to high phase profile errors due to the decreasing wavelength. To decrease these errors, we developed a phase centre estimation method that corrects the phase profile of the antenna radiation pattern. Using the antenna scattering parameters obtained with a vector network analyser, the method accurately calculates the phase centre location with respect to the rotation centre. The method shows promising results on both simulation and measurement data of horn antennas.