FMCW radars at 95 and 183 GHz for planetary and earth science remote sensing

We are developing two prototype millimeter-wave radars at 95 and 183 GHz with a frequency-modulated continuous-wave (FMCW) architecture. The 95 GHz radar is intended to measure distributions and velocities of small particles in space, such as those ejected in cometary jets. The 183 GHz radar is to operate across the atmospheric water absorption line to perform humidity sounding inside clouds. Here we discuss the choice of frequency and critical components for the two radars and show some early performance results.