Design of W-Band VCOs with high output power for potential application in 77 GHz automotive radar systems

It is demonstrated that SiGe bipolar preproduction technologies are well suited for VCOs in 77 GHz automotive radar systems. Due to the relatively high output power aimed at, the designer has to consider the physical transistor limits carefully. The VCOs need a single supply voltage only and have been fully integrated (including resonant circuit and output buffer) on a single small (1 mm(2)) chip, demonstrating their low-cost potential. First experimental results based on a not fully optimized design showed at a center frequency of about 77 GHz, a tuning range of 4.3 GHz and a phase noise of -95 dBc/Hz at 1 MHz offset frequency. The total, signal power of both outputs is 14.3 dBm. Simulations demonstrate a further potential increase of total output power (for two or four outputs) by about 5 dBm.