Mobility

Optimization of SiGe VCOs for Wireless Applications

Date Added: Jan 2011
Format: PDF

This paper describes the optimization of phase noise performance in fully integrated SiGe HBT differential LC-tuned Voltage Controlled Oscillators (VCOs) for wireless applications. An accurate expression for phase noise in SiGe HBT LC-tuned VCOs is presented which takes the non-linear operation of the oscillator into account. The expression is derived using conversion-matrix analysis and includes the transfer of wideband noise sources in the LC-tuned VCO into close-in phase noise. Design methods are shown which minimize the different sources of phase noise toward the intrinsic limit set by the resonator quality factor