The HA-0543GS-KF is a high-performance Double Ridged Broadband Waveguide Horn Antenna professionally engineered and manufactured by Fei Teng Wireless Technology Co., Ltd. (FT-RF) for advanced wideband RF testing and millimeter-wave validation. Operating across an extensive frequency spectrum spanning the continuous 5 GHz to 43.5 GHz range, this laboratory-grade antenna provides stable directional gain profiling from 2 to 16 dBi. Precision-machined with optimized inner double ridges, its physical geometry minimizes boundary interference and guarantees pure radiation patterns with exceptionally low transmission loss. Equipped with a high-precision 2.92mm K-Female coaxial interface connector, this ultra-lightweight 55g antenna safely handles up to 25 Watts of continuous wave (CW) input power and 75 Watts peak power. It stands as an essential reference standard for advanced 5G wireless network testing, satellite communication development, high-frequency anechoic chamber testing, and comprehensive EMC/EMI compliance sweeps requiring professional Taiwanese engineering excellence and absolute measurement reliability.