The implementation of an operational network of microwave radiometers is presently hampered by the cost and complexity of the available instruments. For this reason, the definition and design of a low-cost microwave radiometer suitable for automatic, high-quality observations of liquid water path (LWP) were one objective of the BALTEX cloud liquid water network: CLIWA-NET. In the course of the project, it turned out that a full profiling radiometer with 14 channels can be produced at only about 30% higher cost than a classical dual-channel IWV/LWP radiometer. The profiling capability allows simultaneous observations of LWP and the lower tropospheric (0–5 km) humidity and temperature profiles with a temporal resolution of less than 10 s and a vertical resolution from 100 m to 1 km in the planetary boundary layer depending on height and atmospheric conditions. The latter is possible due to an elevation scan capability and by the implementation of a new filter bank design. The radiometer has several additional sensors.