Efficient Phase Center Estimation Method for OTA Beamforming Characterization

An efficient estimation method of array element phase center assisted by electromagnetic simulation is proposed based on the active-element pattern approach. The element phase centers can be estimated by least-squares regression within properly selected angle range according to the measured and simulated element phase patterns. For demonstration, two Ku- band slotted SIW array antennas intentionally installed with geometric offsets with respect to the rotating pivot are measured and well characterized. Eventually, the effects of phase center offsets on beamforming performance are discussed in detail. The proposed method facilitates the verification of array performance.