A high power and wide tuning ra transmitter (TX), composed of a VCO and a operating from -40°C to 125°C for 76-81GHz au presented, and for the first time, demonstrates CMOS technology for automotive radar automotive operating temperature range. Using 65nm bulk technology, high output power of and 10dBm at 125°C is demonstrated with a 1 power variation across the operating temperat It is achieved by merging two sets of transm power matching network together for power single-ended output. A cross-coupled VCO frequency doubler is used to provide more tha range to cover process-voltage-temperature ( The 77GHz phase noise at the output is -87d offset. The overall power consumption is 420mW