A Low-Phase-Noise 77-GHz FMCW Radar Transmitter With a 12.8-GHz PLL and a $\times$6 Frequency Multiplier

In this letter, a 77-GHz transmitter (TX) with a 12.8-GHz phase-locked-loop (PLL) and a $\times$ 6 frequency multiplier is presented for a FMCW radar sensor in a 65-nm CMOS process. To realize the low-phase-noise TX, a voltage controlled oscillator (VCO) with an excellent phase noise performance at a lower fundamental frequency (12.8 GHz) is designed and scaled up ( $\times$ 6) for the desired target frequency (77 GHz). The measured FMCW modulation range with an external triangular chirp signal (1-ms sweep time) is 601 MHz. The output power and the total DC power consumption of the TX are 8.9 dBm and 116.7 mW, respectively. Here, a good phase noise level of -91.16 dBc/Hz at a 1-MHz offset frequency from a 76.81-GHz carrier is achieved.