Recent advances in millimeter-wave radar component technology have led to the development of a new generation of radars above 30 GHz. These radars are more reliable and versatile than their predecessors, consequently gaining popularity among the remote sensing community, particularly among atmospheric scientists. Since 1990, at least 30 millimeter wave cloud radars have been built worldwide for atmospheric science applications. Many of these radars operate near 35 GHz, where atmospheric attenuation due to water vapor and liquid water is considerably reduced as compared to attenuation near 95 GHz. Cloud radars operating at 35 GHz generally employ comparatively energetic transmitters (10-100 W average power) and large antennas (1-3 meters diameter). 95 GHz cloud radars, which benefit from the increase in small droplet scattering efficiency, typically operate with less average power (0.1 to 15 W) and smaller antennas (0.3 to 2 m diameter).