This thesis presents algorithms and tools for the automated design of RF LC CMOS voltage controlled oscillators (VCOs) with low phase noise given a set of specifications. The electromagnetic solver, ASITIC, combined with the circuit simulator, SpectreRF, allows optimization of the VCO circuit parameters and inductor layout. This approach gives a phase noise improvement of up to 20 dBc/Hz in the flicker noise region and up to 5 dBc/Hz in the thermal noise region. An optimization program for the computer-aided design of on-chip spiral inductors has also been developed. This program allows the designer to obtain the layout of an inductor with a required inductance value and maximal quality factor, thus enabling a reduction in the phase noise of the VCO being designed. The circuit simulator SPICE3 has been extended to handle phase noise analysis based on a non-linear perturbation analysis for oscillators. The implemented technique allows for an accurate simulation of phase noise due to devices described either by analytical or numerical models. With this extension, the automated design of RF LC oscillators can be performed within the SPICE3 framework. Furthermore, the technique is available in a public domain software and can be extended to other application domains. / Graduation date: 2004