This article presents the results of a study on the formation of signals from an autodyne short-range radar system with linear frequency modulation for a moving reflecting object. The autodyne signal charts are obtained for cases when the duration of the signal is much longer than the delay of the reflected radiation, as well as for cases when this inequality is not fulfilled. Experimental data were obtained from an oscillator based on an 8-mm Gunn diode, with frequency tuning performed using a variable capacitor.