Research on Amplitude and Phase Testing Method of the Phase-Frequency Scanning Array

Phase-frequency scanning array is widely used in military and civil affairs for its low cost of frequency scanning and flexible phase sweep control. The gain and phase scan beam sidelobe of the array are greatly affected by the amplitude and phase consistency of the channel and need to be calibrated and compensated to obtain high performance beam. Accurate and efficient channel amplitude and phase test method is the premise and foundation of calibration. The radiation characteristics of the waveguide slot antenna in the near-field region of phase scan array are analyzed and the feasibility of sampling in the cylindrical wave region is obtained. On the basis of this, five testing methods, including row by row moving sampling of scanning frame and midfield sampling, are proposed, and the amplitude and phase compensation method of path difference is given. The systematic errors induced by each test method are calculated and their applications are analyzed. Finally, the amplitude-phase test results of the two methods in a phase-frequency scanning array prototype are compared, and the beam test results after compensation calibration are given to verify the accuracy and effectiveness of the proposed method.