Measurement and evaluation techniques for an airborne active phased array antenna

The phase of each element of an airborne active phased array antenna must be adjusted to specified values for the antenna to realize its maximum efficiency and low sidelobe characteristics. This makes it necessary to determine the initial phase relationships of the antenna elements. The rotating-element electric field vector method (REV method) permits these measurements to be done without using additional equipment, such as a scanning pickup horn or a phase-amplitude receiver. The use of the REV method is not restricted to the initial phase measurement. This method is applicable to a built-in correction of an airborne active phased array antenna and to a precise null direction measurement of a monopulse pattern.