Silicon for cheaper radar

Scientists at the University of Wisconsin-Madison have found a way to make radar guided car safety systems cheaper.

Radar systems can be fitted to cars to detect an impending crash and then warn the driver or apply the brakes, but the semiconductor materials used to manufacture radar are very expensive, according to Electrical and Computer Engineering Assistant Professor Zhenqiang Ma.

A team led by Ma has now devised a way to make car radar systems based on silicon, which is less expensive and more robust. Silicon is also easier to manufacture than the materials in today's radar systems as the processes for creating silicon-based devices are much better established.

Car radar operates at extremely high frequencies. The team used silicon devices known as heterojunction bipolar transistors (HBTs), which act as signal amplifiers. To get HBTs to operate at radar frequencies, the devices were made very small, and to achieve the high power levels radar requires, many HBTs were joined together in an array.