Ultra low phase noise 19 GHz VCO design in bipolar technology

The thesis treats a design for an ultra low phase noise VCO for backhaul Gbit point-to-point communication 81-86 GHz. Two VCO-circuits have been designed for a frequency of 19 GHz with a tuning range of more than 10 % and a phase noise below -120 dBc/Hz at an offset frequency of 1 MHz. Both circuits use INFINEON's bipolar SiGe process offering high speed transistors, a high-Q varactor and a thick top metal level. One VCO circuit uses the varactor directly coupled to the integrated inductor requiring a tuning voltage up to 10 V. Although also comparable phase noise commercial products from HITTITE require such unconvenient high tuning voltages. A second version was implemented based on an integrated transformer and operating with a tuning voltage between 0 and 3.3 V. The power consumption of both implemented VCOs is 20 mA from a single 3.3 V supply voltage