Motion detectors with microwave, especially residential sensors, don't use it as the sole detection method. It's always paired with passive infrared. Microwave

Motion detectors with microwave, especially residential sensors, don't use it as the sole detection method. It's always paired with passive infrared. Microwave interference doesn't really make any sense because he'd have to be tripping the infrared and microwave source at the same time. Source: I wrote firmware for microwave/PIR motion detectors for a few years.