Dual-Beam and Wide-Angle Steering AESA with Antenna Size Scalability for Ka-Band SATCOM

We developed RX AESA (Active Electronically Steered Array) as a ground terminal for Ka-band GEO, MEO and LEO satellite communications. Our AESA development goals are to achieve low profile, wide coverage characteristics, scalability of antenna size and simultaneous dual-beam formation. For higher G/T performance in wideband and wide-angle beam steering, we developed a stacked patch antenna with WAIM PCB. Furthermore, we developed a PCB technology that seamlessly connects the PCBs, this can realize antenna size scalability. Finally, we fabricated a 1,024-element Ka-band RX AESA and evaluated its radiation characteristics. As a result, steering envelope characteristics of cos<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1.1</sup>(steering angle) were obtained in the frequency range of 17.7 to 21.2 GHz, for both circular polarization and steering angles up to 80 degrees. This characteristic was obtained in both beams, and more than 30 dB of beam-to-beam isolation was obtained. In two 1,024-element sub-array PCBs, the element space between PCBs could be reduced to a difference of less than 0.5 mm compared to the element space inside the PCBs. Our AESA is capable of wideband, wide-angle steering, dual-beam forming, and scalable antenna size without increasing the sidelobe level. It can realize Ka-band communication for GEO/MEO/LEO satellites in airplanes, cars and other vehicles.