77Ghz is mainly used on forward warning systems, while 24Ghz is used on rearward and sides.
Compared to 24Ghz, 77G has an even wider detection range, more accuracy, smaller unit and less consumption.  Although it provides better performance, the technology is only limited to leading companies such as Bosch, Continental, Dephi.  HD united company is immersed in the researches and developments, making mass production of 77G radar system comes soon.