Antenna performance evaluation method and apparatus

Abstract

Phased array antennas are rapidly tested for performance degradation utilng a beam steering computer unit and built-in test equipment. The antenna includes a plurality of bays in a planar matrix, each bay having subarray modules containing pairs of dipoles. The beam steering unit controls scanning of driver cards having drivers which apply bias voltages to phase shifter diodes or bits of various fixed angular sizes in a main array and subarray. The bits are sequentially tested for current faults, with information obtained on number, size, and location of failed bits determining performance degradation of a predetermined threshold. Larger phase bits of the main array are given more weight than smaller subarray bits. The effect of the failures on sum beam gain and azimuth and elevation differences pattern null depths are computed and compared with the threshold to indicate whether performance is acceptable.