Mini-radars for a smart environment
Millimeter-wave radars are sensors that use radio waves with a very short wavelength (1 to 10mm; frequency band 30 to 300 GHz) to detect objects. They are currently used in more expensive cars to assist with parking and to detect pedestrians and other vehicles, as well as to help prevent collisions. The number of radars used in cars will increase enormously in the years ahead as self-driving cars come on to the roads. The major advantage that radar has over cameras is that radar keeps working in poor (weather) conditions such as fog, dust, snow, excessive glare, etc.
Car radars use the 79GHz frequency band. Other frequency bands are also possible (e.g. 60 and 140 GHz) and these bands make new applications possible, such as presence/motion detection in buildings (for controlling lighting and climate). In these cases, the radars are more precise than current motion detectors, plus they are more ‘discreet’ than cameras. The advantage of a higher signal frequency – such as 140 GHz – is that the radar can be made even smaller and more sensitive.