The WI-42-UBR-15E is a precision-engineered K-Band E-Plane Sectoral Horn Antenna professionally designed and manufactured by Fei Teng Wireless Technology Co., Ltd. (FT-RF) for specialized wide-horizontal illumination fields. Operating within the high-frequency spectrum across the continuous 18.0 GHz to 26.5 GHz frequency band, this premium antenna is expertly flared in the E-plane to deliver a distinct, highly predictable Fan-Beam radiation pattern profile (77° H-plane x 16° E-plane) combined with a calibrated nominal gain of 15 dBi. Featuring a Direct Waveguide Input interface with a standardized UG-419/U (UBR Style) flange mating face, it ensures flawless structural impedance coplanarity and ultra-low-loss power transfer, safely managing continuous wave power loads up to 500 Watts (CW). Precision CNC machined from high-grade structural aluminum alloy in Taiwan, it exhibits exceptional electromechanical longevity, a robust 220g profile, and excellent pattern isolation metrics combined with a maximum V.S.W.R threshold of 1.3 : 1. It stands as the definitive choice for wide-horizontal beam scanning grids, automated antenna characterization ranges, industrial EMI/EMC compliance validation scanning, professional 5G research, and mission-critical satellite link verification setups demanding uncompromised millimeter-wave performance parameters.