Transmitting Near-Field Measurement of Full Digital Active Phased Array Antennas for Multi-Function Radar Application

Recent advances in hardware have resulted in the introduction of an integrated transmit/receive single chip that can not only transmit and receive RF(Radio Frequency) signals, but also perform analog to digital data conversion. This makes it easier to develop element-level digital active phased array(DAPA) antennas. Owing to that, there is an increasing demand for the single chip in radar applications, including the multi-function radar. The transmitting(Tx) near-field measurement configuration applied to verify the performance of the traditional analog active phased array antennas is no longer applicable to DAPA antennas. Therefore, the Tx test configuration applicable to DAPA antennas was proposed. In this paper, the overall Tx near-field test procedure has been described through the proposed test configuration. The measured and ideal results were reviewed and compared. Additionally, considering the structural characteristics of DAPA antennas, a simpler EIRP(Effective Isotropic Radiated Power) measurement method than the conventional one was presented. The validity of the proposed method was verified by comparing it with the results of conventional measurement and theoretical calculation.