Methods and apparatus are disclosed low power motion detection by a radar apparatus. One example radar apparatus includes a transmitter to transmit a pattern of chirps. The transmitted pattern includes a first series of chirps transmitted during a first time period and a second series of chirps transmitted during a second time period that begins after passage of a sleep time period from an end of the first time period. The example radar apparatus also includes a receiver to detect returning chirps including reflected portions of the transmitted pattern. The example radar apparatus also includes analog to digital converter (ADC) coupled to the receiver. The ADC is to sample analog signals from the receiver to generate ADC samples for the returning chirps detected by the receiver.