A Highly Integrated 3-D Printed Metallic K-Band Passive Front End as the Unit Cell in a Large Array for Satellite Communication

We present a three-dimensional (3-D) printed metallic K -band (18-26.5 GHz) passive front end for satellite communication. It is intended to be used as a unit cell in a large antenna array. The proposed front end is composed of a two-stage 1 \times 4 power divider, rectangular-to-circular waveguide tapers, and a linear four-element conical antenna array, which are too complex to be fabricated by a traditional machining process in a whole piece. Taking advantage of the 3-D printing technology in realizing complex structures, we achieve a highly integrated passive module. A good agreement is achieved between simulation and measurement. The proposed front end has impedance bandwidth 19-21 GHz, the maximum gain of 15.5 dBi at 21 GHz, and desirable radiation patterns on both E - and H -planes. The influence of fabrication tolerance like the surface roughness and dimensional tolerance are observed and analyzed. Compared with traditionally fabricated metallic microwave passive devices, the proposed work has a shorter turnaround time and a lower cost. Compared with dielectric 3-D printed microwave devices, it features more simplicity in terms of process and better physical robustness. It opens up new possibilities for microwave device fabrication.