Bent coplanar waveguide feeds for balanced planar antennas and arrays

Abstract

Abstract Planar antenna arrays of a balanced structure are of great importance in many applications due to their features including low‐profile, wideband, and high polarisation purity. However, feeding such antennas adds great complexity in terms of manufacturing and reduces the performance due to production of common mode propagation. A method for feeding such antennas using coplanar waveguide on a thin substrate is proposed. Not only does it terminate the antenna of a balanced structure with a single‐ended feed but it also enables impedance transformation. The design was an attempt towards a completely printed front‐end that incorporates the antenna elements and their feeding circuits on bendable substrates. The electromagnetic performance has been validated with a dual polarised prototype and its prospect for ultrawideband arrays, e.g. 5G sub‐6 GHz or square kilometre array, was explored.