Looking for an answer to current bulky radars in the market, a team of researchers from the KAUST University and the VTT Technical Research Center of Finland, have created, a compact, low-cost radar with potential applications in healthcare and personal security.
Radar technology has been used for decades in aviation, defense and speed-camera technology. It provides detailed information about the size, distance and speed of moving objects. However, for close-range applications, the transmitted radio waves must have short wavelengths to pick up as much detail as possible about its immediate environment. Such sensors could help visually impaired people, and unmanned moving devices, to see by translating radar reflections into useful information.
Current radar modules are large and bulky. They also lose out on key details because they operate using long radio wavelengths. The team thus wanted to develop a low-power, portable radar. The researchers at VTT brought the necessary experience in millimeter-wave and hardware design, while KAUST University focused on the signal processing side and developed modular radar software. The earliest prototype performed a single scan every two seconds, making it difficult to acquire enough input data. They then optimized the signal processing modules and improved the performance to eight scans per second, providing better real-time monitoring.
The new device design incorporates frequency-modulated continuous wave (FMCW) radar. This means the radar produces continuous pulses of millimeter-wavelength radio waves which have a frequency that varies during each pulse. The small wavelength means that the time taken for pulses to reach an object and reflect back, and therefore the distance to the object, are calculated accurately. To limit the size of the system, the team chose an operating frequency of 24 GHz. This enabled them to reduce the size of the microstrip antenna. The design also has one transmitting and two receiving antennae, meaning it can better estimate the angular location of a target.
The device fits into a 10-centimeter box, weighs less than 150 grams and is powered by a 5V battery. Initial trials suggest the device is capable of target detection, speed estimation and tracking at ranges of up to 12 meters. The team even used it to detect whether a person was breathing when sitting in a chair. The prototype may also be useful for unmanned robotic and quadcopter applications where a collision avoidance system is required. Seifallah Jardak worked on the project under the supervision of Sajid Ahmed and Mohamed-Slim Alouini from KAUST along with Tero Kiuru and Mikko Metso from VTT.
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