This document discusses the development of millimeter-wave radiometers operating at 130 and 166 GHz to support the Surface Water and Ocean Topography (SWOT) mission. Key components developed include monolithic microwave integrated circuit (MMIC)-based pin diode switches covering 80-190 GHz and prototype radiometers at 130 and 166 GHz. The high frequency radiometers aim to enable wet path delay measurements closer to coastlines and over land to support the SWOT mission objectives.