| Summary: | 博士 === 國立臺灣大學 === 電子工程學研究所 === 101 === Safety is undoubtedly one of the most important issues of automotive transportation. The millimeter-wave (MMW) radars which can be operated well at day, night and most weather conditions are superior to the other radar technologies such as the ultrasonic, infrared and laser radars. The MMW long-range radar (LRR) which this dissertation focuses on operated at 76–77 GHz for range detection up to 150 m is used for ACC. The ACC system senses the distance and relative speed of the object vehicle in front of the sensing vehicle to adjust acceleration and deceleration of the latter to ensure safe stopping distance. Due to the high performance-to-cost ratio when compared to frequency-shift keying (FSK) and pulse radars, the most commonly used LRR is frequency-modulated continuous wave (FMCW) radar. With the development of advanced CMOS technology, CMOS has become a favorable technology for MMW circuits because of low cost and high level of integration. The availability of low cost CMOS radar transceiver is a key to wide spread adoption of 77-GHz automotive LRRs. Interference will be a serious issue when automotive radars become popular. The radar signals of the vehicles in the adjacent lanes on highway may cause interference and ghost target detection. In this dissertation, an integrated 77-GHz CMOS long-range automotive radar transceiver with the capability of mutual interference reduction is presented. A fractional-N frequency synthesizer is chosen for FMCW generation since it has the advantages of small area occupation and low power consumption compared with direct digital frequency synthesizer (DDFS) when the fine frequency tuning is required. The frequency-hopping random chirp FMCW technique is developed to lower the possibility of false alarm by making mutual interference noise-like. The center frequency of the frequency sweep may hop to another frequency at the end of every sweep cycle. Moreover, the chirp bandwidth (frequency sweep range) and slope of frequency sweep can be altered every cycle. The modulation scheme makes the interference signals less likely to be correlated to the desired signal and results in noise-like frequency response for the mutual interference after received signal is demodulated. The integrated transceiver circuit was implemented in TSMC 65-nm CMOS technology with 1P9M and the occupied silicon area is 1030 μm by 940 μm. The measured receiver gain and noise figure are 23 dB and 14.8 dB respectively. The output power delivered by the transmitter is 6.4 dBm. The frequency-hopping random chirp FMCW function is tested by using analog demodulation function of the signal analyzer after the output signal is divided by 64. The total power consumption of integrated transceiver is 275 mW.
|
|---|
