How Does a Microwave Sensor Work?

Microwave sensor

How Does a Microwave Sensor Work?

Microwave sensor work by emitting a constant signal into their surroundings. When something moves, it disrupts the wave causing it to take a slightly longer time to reflect back to the sensor.

This high-reliability sensor combines field-proven Southwest microwave detection technology with advanced embedded Digital Signal Processing to reliably distinguish intrusion attempts from environmental disturbances, mitigating risk of site compromise and preventing nuisance alarms. This makes them ideal for securing large outdoor areas.


Microwave sensors emit continuous waves of microwave radiation and look for a change in their frequency when they bounce off of objects. They are more accurate than PIR detectors and can be used indoors or outdoors, making them a versatile choice for many types of applications. They are also easy to install and require very little maintenance, making them a great option for commercial buildings or office spaces.

As a safety precaution, these sensors should not be used in areas where people may be moving around. However, these devices can still be triggered by some things that are not dangerous, such as the movement of curtains or sun patterns. Some models have the option to reduce the number of false alarms, ensuring that only intruders are detected and that the lights are not turned on by everyday activities.

These sensors work in a similar way to sonar, sending out microwave signals and measuring how long they take to return back to the sensor. When a person moves into the detection zone, this disrupts the signal and changes the echo time, which causes the light to turn on. Microwave sensors are less reliant on line of sight than PIR sensors, which makes them a good choice for oddly shaped rooms or large spaces with obstacles. This makes them ideal for industrial spaces, warehouses and other commercial facilities.


Using Doppler radar technology, these sensors detect movement by projecting microwaves that bounce off objects and return to the sensor. They then measure the time it takes for these signals to return to the sensor (the time taken to create a baseline). If someone moves into the detection zone, the microwave signals are disrupted and the echo time changes, triggering the light.

Microwave sensors are also able to work through Merrytek Intelligent sensor walls and glass, so they’re great for large spaces that don’t have a clear line of sight. They’re also more sensitive than PIR sensors, so they can pick up movements from a wider range of angles.

They’re often pricier than other types of sensors, but they offer superior performance. They can also be hardwired or wireless, and they’re great for high-security sites that require sensitive motion detection.

At Martec, we carry a wide range of PIR and microwave sensor lights that are ideal for commercial applications. Whether you’re looking for something simple and cost-effective or more complex and advanced, we have the perfect solution for your needs. All our PIR and microwave sensor lighting is manufactured by top-tier companies with excellent reputations. This allows them to take advantage of lower production costs, allowing them to pass on the savings to you. This, combined with our quality and affordable labor rates in China, provides you with a world-class product at an unbeatable price.


A microwave sensor is a line voltage sensor that works based on occupancy. It can turn lights on and off based on the movement of people in the detection range. It operates differently from PIR sensors, projecting microwaves that bounce off surfaces and return to the detector. The sensor then analyses this information to detect motion. It is a versatile, reliable and effective sensor system, allowing for greater flexibility than traditional photo-electric systems. It is also less susceptible to environmental factors such as vibration, air flow and dust that may cause nuisance switching.

Microwave sensors are able to perform well in areas with metalloid barriers which can impair the performance of PIR motion detectors. This makes them ideal Microwave sensor for applications like warehouses, prisons, and transformer substations. They can also be used in high heat environments that would otherwise fry PIR sensors.

The microwave sensor uses a Doppler principle to detect movement. It measures the time it takes for the microwave signal to echo back from an object in the detection range, and if the delay is longer than normal, the sensor triggers a light. This provides a reliable, low-energy, and cost-effective solution for many types of indoor and outdoor lighting applications. However, it is important to keep in mind that this technology has some drawbacks. For example, the microwave sensor can be triggered by things such as moving drapery or changing sunlight patterns. Additionally, microwave sensors require continuous power draw and work at intervals rather than continuously, which means that someone who runs fast enough could potentially evade detection.


A microwave sensor works by sending out microwaves that bounce off objects in the area. When something interrupts this pattern, the sensor can detect a change in frequency that tells it there is an intruder. It can also determine if the intruder is moving towards or away from it, making it an excellent choice for securing properties with high traffic areas.

Unlike PIR sensors, microwave motion detectors are safe to use inside and outside of a property, so they can cover a larger area. They are also great for detecting movement in areas that are usually hard to reach or have no fence line, such as warehouse aisles.

One disadvantage of this type of sensor is that it can be affected by a variety of environmental factors. For example, air flow can cause nuisance switching and vibration can interfere with the signal. It is therefore important to choose a location that is free from these effects.

In addition to evaluating normalized sensitivity, a coplanar waveguide fed open stub resonator sensor has been used to test the oil permittivity of some liquid materials. Akhtar and Shafi [47] explored the effect of different mixtures on the sensor’s normalized sensitivity. The results indicate that this method may be useful for non-destructive testing of liquid materials and a possible alternative to X-ray inspection.

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