IMPROVED THE QUALITY OF THE TRANSMITTER INTERNAL CALIBRATION OF DIGITAL PHASED ARRAY ANTENNA SYSTEM

Abstract

This paper proposes a solution to improve the quality of transmitters calibration of the digital phased array antenna system in real-time. The internal calibration method is a widely studied and applied method to achieve real-time in calibration. However, the method has a major limitation, which is signal leakage in the module, which causes large errors in calibration. The article proposes a solution to overcome the above limitation in transmitter calibration. It is to delay the extracted calibration signal at the output of the transmitter module by the "delay-line". With this solution, the correlation between the calibration signal and the leakage signal will be significantly reduced, thereby reducing the error of the measurement. The effectiveness of the proposal is analyzed on the basis of theory and demonstrated through simulation. With a sufficiently large delay selection, the simulation results with the BPSK (Binary Phase Shift Keying) sequence of length 1000, show that the correlation of the two signals is reduced by about 31.6 times, corresponding to the isolation level of the two signals increasing by 30 dBc.