A Highly Integrated Active Antenna Subarray for Spaceborne SAR Applications

A highly integrated active subarray is proposed for synthetic aperture radars. In order to achieve high integration and low profile, a three-layer integration scheme is employed by vertically connecting the radiating elements, T/R modules and an active electronics board. The radiating element layer is a wideband patch antenna integrated with a circulator. The T/R module uses a three-dimensional package structure basing on a multi-function chip. The active electronics board has the function of signal distribution and provides the mounting surface for time-delay modules, power module and control module. A blind-mating mechanism of the aforementioned three layers solves the interconnection of RF, power and control signals. The active subarray prototype testing results show that instantaneous bandwidth of 3.4GHz, scanning angle of ± 45° and dispersion less than 3° by using time-delay compensation is obtained on a low profile less than 6cm and a weight less than 250g.