What is a Microwave Motion Detector?

A microwave motion detector is a security sensor that uses a microwave radar to detect the presence of motion. This type of radar works by continuously sending out microwave signals. The signals should bounce off the objects in the room and return to the sensor with consistent timing.

Assuming that there is no motion present in the room, everything that the sensor detects will remain consistent. The microwave signals will bounce off any objects or structures that are present and return to the sensor in essentially the same manner every time. This is how the sensor will check to ensure that no intruder is present.

However, if a person walks into the room, then the microwave signals will bounce off of them. This will change the manner in which the signals are returning to the motion sensor. The sensor will then recognize this change and cause a fault for its corresponding zone on the alarm system. Please note that the change in the detected microwave signals will need to be significant enough for an alarm to occur, as small changes will not activate the sensor.

It should be mentioned that standalone microwave motion detectors are relatively uncommon. Most microwave motion sensors also utilize PIR technology to detect motion. This technology works by looking out for significant changes in infrared energy. If a substantial change in infrared energy is detected, the sensor will assume that motion is present. A motion sensor that uses both of these motion detection methods is often referred to as a dual-tech motion sensor. These motion sensors will require that both the PIR sensor and the microwave sensor be triggered before an alarm will occur.

Microwave motion detectors come in many forms. The biggest distinction is whether the sensor is wireless or hardwired. A wireless sensor, such as the Honeywell 5898, will communicate with the panel using RF signals. This type of sensor is generally very easy to install and program with the system, but it will need to have its batteries replaced every few years. On the other hand, a hardwired sensor can be more difficult to install, since it is necessary to run a wire from the panel to the sensor. However, a hardwired motion detector will never require a battery replacement.