Automatic diagnostic and alignment in phased array antennas

This paper focuses on the conditions and methods required for the improvements in the diagnostic, initial alignment and further self-tuning of multi-channel phased array antennas (PAA), taking into account their constructive peculiarities and restrictions. For proper reconstruction of the aperture field from a near-field amplitude and phase distribution (APD), the evanescent components in the computed far-field spectrum must be excluded from the inverse process with the fast Fourier transform techniques and the correction on the far-field spectrum must be done to remove the contribution of the probe pattern and element factor before the inverse transform, as well as the correction of the probe position errors. The paper discusses the concepts "ICAR-7" (computer-controlled near-field measurement system ) is based on, the way these concepts are implemented in practice, the measured performance, methods and the procedures being adopted for efficient utilization of this antenna test facility for array monitoring and alignment.