Design of Ka band High Gain Spaceborne Phased Antenna Array

Coping with the requirements of high performance spaceborne phased antenna array in SAR system, a Ka band active phased antenna array with all-in-one design is provided in this paper. The radiating element adopts waveguide slot antenna where the slots are open in the narrow walls without inclines, the antenna has the advantage of high gain and well impedance matching. The calibration network and the feed network are all realized in waveguide forms. For the calibration network, an extra layer is added on the waveguide transmission lines, so as to absorb the unwanted powers from the output ports due to the mutual coupling between channels, by which the channel's consistency is improved. For the feed network, the magic T structures are adopted in the power dividers to decrease the coupling between channels. The calibration network and the feed network are all integrated at the back of the antenna, and fabricated using an all-in-one method. The antenna array has a high gain of 45 dBi, it also has a compact structure and a low profile, which make it very suitable in satellite radar applications.