Monolithic 38GHz MESFET VCO with integrated buffer amplifier for automotive collision avoidance systems

Design, fabrication, and test results of a Ka-band monolithic MESFET VCO with integrated buffer amplifier are presented. The oscillator can be operated between 36.8 GHz and 38.6 GHz. The use of two independent varactor diodes enables the adjustment of the frequency linearity over a tuning range of at least 700 MHz and a compensation of ambient influences, e.g. temperature drift. The oscillator-amplifier chain generates an output power of more than +18 dBm, which is sufficient to obtain at 76 GHz an RF performance in the range of 10 mW and more via a state-of-the-art MMIC frequency doubler. The described device is a key component for collision avoidance radar applications in Europe.