The adaptive cruise control (ACC) system will be one of the most important applications in the Intelligent Transport System (ITS). The 76GHz vehicle radars are developed in many countries for ITS applications, especially for the ACC system application. The wider the horizontal field of view and the finer the horizontal angular accuracy, the better the radar sensor for ACC system. Because ACC radars have to recognize forward vehicles even at the curve in the road and they also have to distinguish which traffic lane forward vehicles are running under the complicated road environments. The vehicle radar with scanning beams, such as a mechanical scan or an electrical scan will meet these requirements. However an electrical scan is preferable to a mechanical scan from the view point of reliability. Other important requirements for the ACC radar are to decrease its size and cost. It is necessary to employ 76GHz MMICs for the RF front-end of the vehicle radar in order to fulfil these requirements. The transmitter MMIC having the output power of 11 dBm and the receiver MMIC having the conversion gain of -4.6 dB have been developed. Using these MMICs, the 76GHz vehicle radar with electrically scanned seven beams has been successfully developed, resulting in horizontal field of view of 12 degrees and horizontal angular accuracy of less than +/- 0.3 degrees, with the dimension of 120 mm wide, 105 mm height and 93 mm depth. The developed vehicle radar is promising for ACC application and other ITS applications. (A*)
Abstract