Abstract: A frequency-modulated continuous-wave (FMCW) radar system for level or distance measurement in which a frequency modulated signal to be transmitted to a target is mixed with an echo signal from the target to produce a beat signal that passes through an analog filter before being digitized and processed in a digital processor to determine the level or distance to be measured, where a test signal is generated by a signal generator, and a switch is controlled to connect the beat signal or the test signal to the analog filter, the signal generator generates the test signal as a broadband signal having a periodic waveform, e.g., a square wave, and the digital processor calculates a spectrum of the digitized filtered test signal by Fast Fourier Transform and generates a fault signal if the spectrum differs from a reference spectrum by a predetermined amount to allow for failure detection.

Abstract: A frequency-modulated continuous-wave (FMCW) radar system for level or distance measurement in which a frequency modulated signal to be transmitted to a target is mixed with an echo signal from the target to produce a beat signal that passes through an analog filter before being digitized and processed in a digital processor to determine the level or distance to be measured, where a test signal is generated by a signal generator, and a switch is controlled to connect the beat signal or the test signal to the analog filter, the signal generator generates the test signal as a broadband signal having a periodic waveform, e.g., a square wave, and the digital processor calculates a spectrum of the digitized filtered test signal by Fast Fourier Transform and generates a fault signal if the spectrum differs from a reference spectrum by a predetermined amount to allow for failure detection.

Abstract: A horn antenna for a radar device including a dielectric filling body arranged in a hollow horn section of a metal body and a dielectric cover attached to the filling body and sealingly closing the open end of the metal body. The filling body includes a first conical portion that is fittingly received in the hollow horn section, and a second conical portion that is situated away from the open end and dimensioned to leave a gap between itself and the wall of the hollow horn section. The dielectric filling body has a third portion between the first and second portions, where the third portion and the opposite portion of the wall of the hollow horn section are provided with circumferential grooves arranged in pairs opposite each other to provide a wear and maintenance-free attachment of the dielectric filling body in the horn antenna.