An Integrated 20 GHz SiGe Bipolar Differential Oscillator with High Tuning Range

A fully integrated, differential LC oscillator manufactured in Infineons B7HF SiGe bipolar technology with an fT and fmax of 75 GHz is presented. The oscillator features a tank consisting of on-chip stripline inductors and the parasitic capacitances of the oscillator transistors. A tuning range of 14-21.5 GHz over bias current is achieved. The output buffer is inductively coupled to the tank. Total current consumption including the buffer is 13 mA from a 3 V supply at the maximum oscillation frequency of 21.5 GHz. The measured phase-noise at 1 MHz offset is -85 dBc/Hz at a core bias current of 7 mA.