Reduced beam-squint series fed horn array manufactured using additive manufacturing

Abstract

In this work, a series-fed antenna is designed with beam-squint compensation. The horn array operates between 21.5 GHz and 23.5 GHz. Beam-squint compensation is designed into the array using time delay equalisation, thus keeping the phase of the signal arriving at the radiating horns equal. This is achieved by using power dividers and sinusoidal time delays. The waveguide form factor was WR-42 waveguide. The array reduced beam squint when compared to a reference array with the time delay compensation. The performance of the array was limited by the bandwidth of the time delays and power dividers. The array is additively manufactured using stereolithographic apparatus printing technology and electroless silver plating to create the conductive surfaces needed for the waveguide. This work extends previous work by providing a detailed analysis of the plating performance. The silver plating was also used as a seed layer for copper plating. The manufactured parts were compared to titanium- printed versions. The silver plated parts performed better than the titanium-printed parts in terms of manufacturing cost and waveguide losses. Furthermore, the titanium printed waveguides needed post-processing to achieve the best performance. There was little benefit in performance when copper plating onto the silver with a basic copper plating approach.