Phase Center Of The Detective & Direction-finding Antenna

In the interception and Direction-finding system, the phase center of the antenna is very important to the Direction-finding, however, the phase center of directional antenna is few studied in the home and overseas. This paper is worked to solve the phase center of the directional antenna, accordingly to giving some references for the interception and Direction-finding system.In this paper, the variable phase center is calculated in the full space for the first time. The condition under which a linear array has a variable phase center in the full space is derived in the paper. It is concluded that the non-similar array has not variable phase center in the full space, but it has variable phase center in the E-plane and H-plane independently.The mathematical expression, which is used to calculate the variable phase center based on the MoM, is derived first in the paper. It is proved that the variable phase center of the LPDA is not superposition in the E-Plane and the H-Plane. Moreover, the fish antenna is often used in the detection system. The variable phase center of the antenna is calculated which contain vertical polarization and horizontal polarization. The result demonstrates that the variable phase center of fish antenna is much more steady than the LPDA in the main beam.