I receive the received signal using an unmodulated continuous wave radar sensor and I'm struggling to obtain the relative distance of the object. I receive the IQ data in milli-volts and use the formula delta_phase = arctan2(Q_samples/I_samples), but the change in the phase as I plot is not that big although I keep on moving my hand back and forth from the sensor as I should see larger changes. The sensor is 61GHz and the wavelength is 4.92 mm. Any suggestion if I'm using the data in a wrong way or should I apply filtering before obtaining the phase change ??