US Patent 7639176 Reference pulse generation

The shape or amplitude of reference pulses in a filling level radar typically depend on the component quality of the circulator used, of a transmitting/receiving coupler, or else of the circuit temperature. In case of large echoes at close range, the quality of the measurement may deteriorate. A radar module for extracting a reference signal for a filling level radar comprises a tap extracting the reference signal and a delay line delaying the transmit signal. Delaying the transmit signal on its way to the antenna takes place after the extraction of the leakage pulse.