An example device may include a transmitter, such as a radio-frequency (RF) transmitter, a receiver and a controller. The receiver may include a mixer that generates a beat signal from a received signal and a local oscillator signal. A transmitted signal may include a linear frequency ramp and may be incident on an object, inducing the received signal. The device may include a controller configured to detect a frequency and phase of the beat signal. The device may determine an absolute distance to the object using the beat frequency and a distance component using the beat signal phase. The distance component may be used to increase the precision of an object distance measurement relative to the absolute distance alone. The distance component may be used to detect relatively small movements of the object, such as micron-scale movements. Various other methods, systems and computer-readable media are also disclosed.