The paper considers a method of increasing the sensitivity of a microwave motion sensor based on the Doppler Effect, based on the application of amplitude manipulation of electromagnetic vibrations reflected from a moving object. A microwave motion sensor based on an integrated antenna-oscillator is described, in which amplitude manipulation of the information signal is implemented due to the amplitude manipulation of the reflected oscillations, followed by signal processing at the frequency of the manipulation, which allows reducing the effect of the sensor's own noise on the information signal. The results of an experimental study of such a microwave sensor are given, in which the level of noise and internal interference is approximately 20 dB lower compared to the traditional autodyne mode of operation of the same sensor.