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In our beamformer, there are initial phase and gain offset differences between the element ports due to some mechanical errors.
So, we need to calibrate and minimize them to achieve higher beam control accuracy.
We adopted so-called REV method and MEP method as they are the well-established and well-known calibration technique for the phased array antenna for satellite communication.
REV needs only power measurement, so the experimental setup can be simplified but it requires much time to collect the data for calibration.
In our case, we measured the amplitude of composite electric-field vector 512 times.
On the other hand, MEP needs phase and gain measurements, so the setup may be complicated but it takes less time.
In this method, the composite vector variation is observed while the phases of multiple elements are simultaneously shifted with different intervals.
And then, the electric fields of the corresponding elements can be obtained by using an FFT for the measured field variation.
Although MEP is faster and more efficient than REV, it requires more accurate phase measurements.
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IEEE/ICACT20210172 Slide.08
[Big Slide]