The Keysight 8473D is a high-performance detector using a gallium arsenide, planar-doped barrier detecting element. It features extremely flat frequency response over its entire band of operation and very good frequency response stability versus temperature. The Keysight 8473D is also very rugged with high resistance to ESD damage. An optimum square-law load and positive polarity output are available as special options (consult your local Keysight representative).