An FMCW Radar for Accurate Level Measurements

The system is intended for tank level measurements and is based on a single linear sweep. By the use of a coaxial cable as a reference and a special calculating process a good accuracy and noise immunity is obtained. The accuracy is typical 0,05 % or 5 mm over a 0-60 m range. One problem with the application is the discrimination of false echoes which is done by a narrow antenna beam, an amplitude threshold and a filter. The calculation and the filtering is insensitive to unlinearities.