MICROWAVE SENSOR

What is Microwave sensor?

The figure-1 depicts microwave motion sensor. As shown it emits frequency in the microwave region and will analyze the returned/reflected microwave frequency for determining motion.

Devices having microwave sensors generate microwave signals which cover certain area across the space. When a person walks into the microwave zone, his body causes waves to reflect. This is detected by the sensor to take appropriate action.

Microwave sensor functions as occupancy sensor like Pir Sensor Microwave sensor is active sensor as it emits microwave signal for detection.

Benefits or advantages of Microwave sensor

Following are the benefits or advantages of Microwave sensor:
➨Microwave sensors can cut substantial amount of energy wastage by turning off lights automatically when area is unoccupied. This saves 40% of electricity expenditure of the companies.
➨Moreover microwave sensors enable auto-dimming of lights which further optimizing the energy charts.
➨They are very sensitive and hence slightest movements are also being detected by them.
➨They have wide coverage range which is about 120 meters.
➨They can detect any motion even beyond the walls or behind the doors.
➨They have benefits of high interference immunity, high precision and high reliability.
➨They require one time servicing to provide lifespan operation.
➨ They can be used in harse environments where heat cycles are irregular.
➨Microwave sensors have wide variety of applications. They are used to monitor functions of bucket elevators and belt conveyors. They are also used for crane proximity detection. City municipalities also use them to monitor waste water and sewage levels.
➨Microwave sensors are used in medical applications such as breast cancer treatment, separation of red blood cells from white blood cells, liver tissue disease detection etc.

Drawbacks or disadvantages of Microwave sensor

Following are the drawbacks or disadvantages of Microwave sensor:
➨Prone to false alarms due to blowing of objects due to wind, emission from fluorescent lights, penetration through walls etc. For example, when they are used for lighting control in small offices, the sensors switch ON lights even when someone is outside the office premises as they can penetrate walls or glass.
➨They have higher sensitivity and hence they can detect non-human presence such as animals, fast moving objects in the air etc.
➨Microwave frequency do not penetrate metal objects and hence microwave sensors can not reach beyond any metal obstruction.
➨Microwave radiation is hazardous for health and hence low power microwave sensors are preferred.
➨They operate at irregular intervals and hence intruders sometimes are left unnoticed.
➨They are slightly costlier compare to PIR sensors.
➨They consume more energy compare to PIR sensors.