查看文章

A motion detection device is provided. The motion detection device includes a first antenna, a voltage-controlled oscillator, a phase detector and a signal processing unit. The first antenna receives a first signal generated by a second signal reflected by a target object, so as to output the first signal to the phase detector or the voltage-controlled oscillator. The voltage-controlled oscillator receives first signal or the second signal and receives a frequency adjustment signal, so as to generate an oscillating signal according to the frequency adjustment signal and the one of the first signal and the second signal. The phase detector receives the oscillating signal and another one of the first signal and the second signal, and generates a first phase output signal and a second phase output signal. The signal processing unit estimates motion parameters of the target object according to the first and the second phase output signal.