Development of a Wideband and High-Efficiency Waveguide-Based Compact Antenna Radiator With Binder-Jetting Technique

A multilayer waveguide-based antenna radiator is proposed to achieve a wide operational bandwidth of high gain and high efficiency in a compact size. It is a 2x2 array, consisting of a feeding waveguide, a matching cavity, and a radiating aperture. The proposed design provides sufficient freedom for the radiator to achieve broadband impedance matching. In order to improve radiation efficiency and avoid drawbacks from the traditional machining techniques, a binder-jetting process using metallic particles is adopted to realize the relatively complicated structure. This 3-D metal-direct-printing technique is competent to fabricate waveguide-based structures with high precision. Experimental results are favorably compared to the results of the fabrication by the machining technique. The measured relative bandwidth with VSWR <= 1.5 is 23.7% (13.0-16.5 GHz). A high efficiency of 90% is obtained at the center frequency, and more than 80% efficiency can be maintained over a 2.3-GHz bandwidth. This paper shows that the binder-jetting printing technique is a promising manufacturing approach to realizing high-performance waveguide-based antennas and microwave components.