Tiny radar imaging chip shrinks cameras by 100x
Currently typical radar cameras usually weigh between 50 kg and 200 kg and are commonly used in large satellites. Despite being small, they can produce images that are of the same high quality if not better compared to conventional radar cameras. They are also 20 times cheaper to produce and consume at least 75% less power.
Developed over the past three years at NTU, the promising technology has already secured S$2.5 million in research funding from Singapore government agencies. The radar chip has attracted the attention of several multinational corporations, and is now being researched for use in Unmanned Aerial Vehicles (UAVs) and satellite applications.
Assistant Professor Zheng Yuanjin from NTU’s School of Electrical and Electronic Engineering who led the research, said that the size and effectiveness of the chip will open up new applications not possible previously.
"We have significantly shrunk the conventional radar camera into a system that is extremely compact and affordable, yet provides better accuracy. This will enable high resolution imaging radar technology to be used in objects and applications never before possible, like small drones, driverless cars, and small satellite systems," says Assistant Prof Zheng.
Current radar camera systems are usually between half and two metres in length and weigh up to 200 kg. They cost more than $1 million on the market and can consume over 1000 W in electricity per hour, the energy equivalent of a household air-conditioning unit running for an hour.
Known as Synthetic Aperture Radar (SAR), these large radar cameras are often carried by large satellites and aircrafts that produce detailed images of the Earth’s surface. Objects longer than a metre, such as cars and boats, can be easily seen by the radar camera mounted on an aircraft flying at a height of 11 kilometers.
Unlike optical cameras which cannot work well at night due to insufficient light or in cloudy conditions, a radar camera uses microwaves (X-band or Ku-band) for its imaging, so it can operate well in all weather conditions and can even penetrate through foliage.
However, the huge size, prohibitive cost and energy consumption are deterrents for use in smaller unmanned aerial vehicles and autonomous vehicles. In comparison, NTU’s radar chip (2-mm x 3-mm) when packaged into a module measures only 3- x 4- x 5-cm, weighing less than 100 grams.
Production costs can go as low as $10,000 per unit, while power consumption ranges from 1 W to 200 W depending on its application, similar to power-efficient LED TVs or a ceiling fan.
It can also capture objects as small as half a metre, which is twice as detailed as the conventional radar camera used in large aircrafts or satellites.
NTU’s tiny microchip for radar imaging embedded on a PCB board (small square chip on the upper right). Image courtesy of NTU Singapore.
Assistant Prof Zheng says that when mounted on UAVs, it can take high quality images on demand to monitor traffic conditions or even the coastlines for trespassers.
"Driverless cars will also be able to better scan the environment around them to avoid collisions and navigate more accurately in all weather conditions compared to current laser and optical technologies," he adds.
"Finally, with the space industry moving towards small satellite systems, such as the six satellites launched by NTU, smaller satellites can now also have the same advanced imaging capabilities previously seen only in the large satellites."
Large satellites can weigh up to 1,000 kg, but microsatellites weigh only 100 to 200 kg. According to Markets and Markets global forecasts and analysis, the global market for radar systems is estimated to grow to US$24 billion by 2020.