Linear polarization gaussian optical lens horn antenna(Conical Horn Feed) LB-GLC-15-30-A, operating from 50to 75 GHz with a nominal 34.5 dB gain and low VSWR 1.8:1 with rectangular waveguide WR15 output. The waveguide flange is FUGP620(UG-385/U). The model LB-GLC-15-30-A gaussian optical lens horn antenna are especially useful when high gain is required with the minimum size. They are composed by feed and lens in order to apply phase correction and achieve superior performance with minimum size. The antenna employs a conical feed horn to offer excellent aperture efficiency, high cross polarization rejections, and low sidelobe levels. The entire antenna is designed with rugged mechanical structure. This antenna can also be converted to dual linear polarization with WOMT(Waveguide Ortho-Mode Transducer), circular polarization with circular polarizer, and dual circular polarization with WOMT and circular polarizer. This horn antenna with rectangular waveguide transition has linear polarization and ideally suited for high gain applications, plasma systems, radar applications, communication and meteorological systems and other applications.