Jacobs, BennieOdendaal, J.W. (Johann Wilhelm)Joubert, Johan2024-06-202024-06-202024-04Jacobs, B., Odendaal, J.W., Joubert, J.: Wideband 0.5–50 GHz double‐ridged guide horn antenna using coaxial‐to‐ridge waveguide launcher. IET Microwaves, Antennas & Propagation 18(4), 248–265 (2024). https://doi.org/10.1049/mia2.12441.1751-8725 (print)1751-8733 (online)10.1049/mia2.12441http://hdl.handle.net/2263/96554DATA AVAILABILITY STATEMENT : The data that support the findings of this study are available from the corresponding author upon reasonable request.Ever-increasing bandwidth requirements from various industries drive the need for the ever-increasing bandwidth of antennas used for testing. Broadband Double-Ridged Guide Horn (DRGH) antennas are used extensively in antenna measurement and ElectroMagnetic Compatibility/Interference (EMC/I) testing. The current state-of-the-art broadband DRGH antennas reported in the literature for use in measurement applications cover bandwidth ratios as large as 36:1 (0.5–18 GHz). This paper presents the design and realisation of a DRGH antenna with a 100:1 bandwidth ratio (0.5–50 GHz). To achieve such a wide bandwidth, the ridge gap, width and feed were optimised, and a novel coaxial-to-ridge waveguide launcher section based on a typical Vivaldi antenna was developed. Backward radiation was reduced using an absorber-filled cavity. A prototype DRGH antenna was manufactured using additive manufacturing, also referred to as 3D printing. Simulated and measured results obtained in an anechoic chamber are presented.en© 2023 The Authors. IET Microwaves, Antennas & Propagation published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License.Double-ridged guide horn (DRGH)ElectroMagnetic compatibility/interference (EMC/I)AntennasAntenna testingBroadband antennasHorn antennasRidge waveguidesUltra wideband antennasSDG-09: Industry, innovation and infrastructureArticle