A system is disclosed for wirelessly detecting movement of a target. The system comprises a reference oscillator, a transmitter, a receiver, a demodulator, and a processor, wherein: the reference oscillator generates references frequencies for the transmitter, the receiver, and the demodulator the transmitter generates a continuous-wave signal at a frequency based on the transmitter reference frequency and wirelessly transmits it to the target the receiver wirelessly receives a reflected signal from the target having a phase angle corresponding to movement of the target and converts the reflected signal into an intermediate frequency signal based on the receiver reference frequency the demodulator demodulates the intermediate frequency signal into an in-phase component and a quadrature component and the processor converts the in-phase component and the quadrature component into a movement signal corresponding to movement of the target.
