76-81 GHz CMOS mm-wave signal generator by Fujitsu for Automotive Radar
Radar and the Lidar are the two key technologies used in self driving or autonomous cars to detect objects. The drawback with Lidar is, in rainy season or during foggy environment Lidar fails to detect objects whereas radar is useful even in those conditions. Fujitsu announced a component for radar which makes the radar further accurate. The CMOS millimeter-wave signal generator from Fujitsu for automotive radars can modulate frequencies in the band width range of 76-81 GHz.
The new signal generator device supports detection of objects at relative speed of 200km/hr, that means if two cars facing each other at a speed of 100km then also these CMOS signal generators can successfully detect objects. These CMOS sensors can detect pedestrians, bicycles or such moving objects on the road accurately. By this Millimeter Wave signal generator and also by using another device called four-channel CMOS transmitter circuit from Fujitsu, it is be possible to measure and control millimeter - Wave beams with a phase precision within 1 degree. The users can scan their surrounding with a high level of precision at high speed, according to Fujitsu. Fujitsu presented this technology at an event called European Microwave Week 2016 (EUMW 2016), which was held on October 3-7, in London.
The idea behind this chip is to expand the use of radar from 77-GHz band to broader band of 79 GHz. These radars can be used not only in front and rear of the vehicles but also on the peripheral sides.
Fujitsu signal generator circuit controls the frequency of the millimeter-wave signal continuously, reads in and counts the millimeter-wave signal pulses, applies a voltage to the frequency controller based on that count, and modulates the frequency. Compared to other signal generators, this signal generator is better due to its performance at higher temperatures. In conventional signal generators, the internal signals slow down and counts become inaccurate. Whereas this one continuously provide accurate counting at higher temperature and also at higher speeds according to Fujitsu. Fujitsu could achieve the accuracy by developing a new time compensating pulse counter that operates accurately even under high temperature of 150 degC. To detect more accurately, this chip uses higher modulation speeds where the chip uses the fastest modulation speed of 2 GHz for every 1 micro sec at 80 GHz band and achieves the maximum relative speed detection (200 km/h) that is expected of radar.
Fujitsu is working on integrating high performance processor along with signal generator so that it can provide more functions in single chip that technology is expected to be available by 2020.